Secondary Driver Research Articles

Drivers of tropical forest loss between 2008 and 2019

During December 2020, a crowdsourcing campaign to understand what has been driving tropical forest loss during the past decade was undertaken. For 2 weeks, 58 participants from several countries reviewed almost 115 K unique locations in the tropics, identifying drivers of forest loss (derived from the Global Forest Watch map) between 2008 and 2019. Previous studies have produced global maps of drivers of forest loss, but the current campaign increased the resolution and the sample size across the tropics to provide a more accurate mapping of crucial factors leading to forest loss. The data were collected using the Geo-Wiki platform (www.geo-wiki.org) where the participants were asked to select the predominant and secondary forest loss drivers amongst a list of potential factors indicating evidence of visible human impact such as roads, trails, or buildings. The data described here are openly available and can be employed to produce updated maps of tropical drivers of forest loss, which in turn can be used to support policy makers in their decision-making and inform the public.

WISDOM Project – X. The morphology of the molecular ISM in galaxy centres and its dependence on galaxy structure

ABSTRACT We use high-resolution maps of the molecular interstellar medium (ISM) in the centres of 86 nearby galaxies from the millimetre-Wave Interferometric Survey of Dark Object Masses (WISDOM) and Physics at High Angular Resolution in Nearby GalaxieS (PHANGS) surveys to investigate the physical mechanisms setting the morphology of the ISM at molecular cloud scales. We show that early-type galaxies tend to have smooth, regular molecular gas morphologies, while the ISM in spiral galaxy bulges is much more asymmetric and clumpy when observed at the same spatial scales. We quantify these differences using non-parametric morphology measures (Asymmetry, Smoothness, and Gini), and compare these measurements with those extracted from idealized galaxy simulations. We show that the morphology of the molecular ISM changes systematically as a function of various large-scale galaxy parameters, including galaxy morphological type, stellar mass, stellar velocity dispersion, effective stellar mass surface density, molecular gas surface density, star formation efficiency, and the presence of a bar. We perform a statistical analysis to determine which of these correlated parameters best predicts the morphology of the ISM. We find the effective stellar mass surface (or volume) density to be the strongest predictor of the morphology of the molecular gas, while star formation and bars maybe be important secondary drivers. We find that gas self-gravity is not the dominant process shaping the morphology of the molecular gas in galaxy centres. Instead effects caused by the depth of the potential well, such as shear, suppression of stellar spiral density waves, and/or inflow, affect the ability of the gas to fragment.

ERG amplification is a secondary recurrent driver event in myeloid malignancy with complex karyotype and TP53 mutations.

ERG is a transcription factor encoded on chromosome 21q22.2 with important roles in hematopoiesis and oncogenesis of prostate cancer. ERG amplification has been identified as one of the most common recurrent events in acute myeloid leukemia with complex karyotype (AML-CK). In this study, we uncover three different modes of ERG amplification in AML-CK. Importantly, we present evidence to show that ERG amplification is distinct from intrachromosomal amplification of chromosome 21 (iAMP21), a hallmark segmental amplification frequently encompassing RUNX1 and ERG in a subset of high-risk B-lymphoblastic leukemia. We also characterize the association with TP53 aberrations and other chromosomal aberrations, including chromothripsis. Lastly, we show that ERG amplification can initially emerge as subclonal events in low-grade myeloid neoplasms. These findings demonstrate that ERG amplification is a recurrent secondary driver event in AML and raise the tantalizing possibility of ERG as a therapeutic target.

Clinical Utility of CDK4/6 Inhibitors in Sarcoma: Successes and Future Challenges.

PURPOSESoft tissue and bone sarcomas are rare malignancies that exhibit significant pathologic and molecular heterogeneity. Deregulation of the CDKN2A-CCND-CDK4/6-retinoblastoma 1 (Rb) pathway is frequently observed in about 25% of unselected sarcomas and is pathognomonic for specific sarcoma subtypes. This genomic specificity has fueled the clinical evaluation of selective CDK4/6 inhibitors in sarcomas. Here, we highlight successes, opportunities, and future challenges for using CDK4/6 inhibitors to treat sarcoma.MATERIALS AND METHODSThis review summarizes the current evidence for the use of CDK4/6 inhibitors in sarcoma while identifying molecular rationale and predictive biomarkers that provide the foundation for targeting the CDK4/6 pathway in sarcoma. A systematic review was performed of articles indexed in the PubMed database and the National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov). For each sarcoma subtype, we discuss the preclinical rationale, case reports, and available clinical trials data.RESULTSDespite promising clinical outcomes in a subset of sarcomas, resistance to CDK4/6 inhibitors results in highly heterogeneous clinical outcomes. Current clinical data support the use of CDK4/6 inhibitors in subsets of sarcoma primarily driven by CDK4/6 deregulation. When dysregulation of the Rb pathway is a secondary driver of sarcoma, combination therapy with CDK4/6 inhibition may be an option. Developing strategies to identify responders and the mechanisms that drive resistance is important to maximize the clinical utility of these drugs in patients with sarcoma. Potential biomarkers that indicate CDK4/6 inhibitor sensitivity in sarcoma include CDK4, CCND, CCNE, RB1, E2F1, and CDKN2A.CONCLUSIONCDK4/6 inhibitors represent a major breakthrough for targeted cancer treatment. CDK4/6 inhibitor use in sarcoma has led to limited, but significant, early clinical success. Targeted future clinical research will be key to unlocking the potential of CDK4/6 inhibition in sarcoma.

Muscular Forces Responsible for Proximal Humeral Deformity After Fracture.

To evaluate the contribution of each of the rotator cuff muscles and deltoid to fracture deformity in a 2-part proximal humerus fracture model. Our hypothesis was that superior cuff muscles would have the greatest contribution to coronal plane deformity, whereas muscles with anterior and posterior attachments would have the greatest contribution to axial and sagittal plane deformity. A medial wedge osteotomy was created in 8 cadaveric shoulder specimens. A custom shoulder testing system was used to load each rotator cuff muscle and deltoid under increasing loading conditions. Fracture displacement was measured using a Microscribe digitizing system. The primary outcome was the contribution of each muscle to varus collapse. Secondary outcomes included contributions of each muscle to apex anterior/posterior deformity and humeral head anteversion/retroversion. Unbalanced loading of the supraspinatus resulted in the greatest varus deformity (34.5 ± 2.3 degrees), followed by the infraspinatus (22.3 ± 3.6 degrees) and subscapularis (21.7 ± 3.1 degree) (P < 0.05). Unbalanced loading of the subscapularis induced the greatest apex posterior (27.5 ± 4.8 degrees, P < 0.05) and retroversion (39.0 ± 5.6 degrees, P < 0.05) deformity, whereas the infraspinatus induced the greatest apex anterior (8.7 ± 3.4 degrees, P > 0.05) and anteversion (17.7 ± 5.7 degrees, P > 0.05) deformity. In this proximal humerus fracture model, the supraspinatus was the primary driver of varus deformity, whereas the subscapularis and infraspinatus contributed to apex posterior/retroversion and apex anterior/anteversion, respectively. The subscapularis and infraspinatus are also important secondary drivers of varus deformity. This study establishes a physiologically relevant fracture model that mimics in vivo conditions for future biomechanical testing.

Inflammation in the Pathogenesis of Arrhythmogenic Cardiomyopathy: Secondary Event or Active Driver?

Arrhythmogenic cardiomyopathy (ACM) is a rare inherited cardiac disease characterized by arrhythmia and progressive fibro-fatty replacement of the myocardium, which leads to heart failure and sudden cardiac death. Inflammation contributes to disease progression, and it is characterized by inflammatory cell infiltrates in the damaged myocardium and inflammatory mediators in the blood of ACM patients. However, the molecular basis of inflammatory process in ACM remains under investigated and it is unclear whether inflammation is a primary event leading to arrhythmia and myocardial damage or it is a secondary response triggered by cardiomyocyte death. Here, we provide an overview of the proposed players and triggers involved in inflammation in ACM, focusing on those studied using in vivo and in vitro models. Deepening current knowledge of inflammation-related mechanisms in ACM could help identifying novel therapeutic perspectives, such as anti-inflammatory therapy.

A Nonlinear Observability Analysis of Ambient Wind Estimation with Uncalibrated Sensors, Inspired by Insect Neural Encoding.

Estimating the direction of ambient fluid flow is key for many flying or swimming animals and robots, but can only be accomplished through indirect measurements and active control. Recent work with tethered flying insects indicates that their sensory representation of orientation, apparent wind, direction of movement, and control is represented by a 2-dimensional angular encoding in the central brain. This representation simplifies sensory integration by projecting the direction (but not scale) of measurements with different units onto a universal polar coordinate frame. To align these angular measurements with one another and the motor system does, however, require a calibration of angular gain and offset for each sensor. This calibration could change with time due to changes in the environment or physical structure. The circumstances under which small robots and animals with angular sensors and changing calibrations could self-calibrate and estimate the direction of ambient fluid flow while moving remains an open question. Here, a methodical nonlinear observability analysis is presented to address this. The analysis shows that it is mathematically feasible to continuously estimate flow direction and perform self-calibrations by adopting frequent changes in course (or active prevention thereof) and orientation, and requires fusion and temporal differentiation of three sensory measurements: apparent flow, orientation (or its derivative), and direction of motion (or its derivative). These conclusions are consistent with the zigzagging trajectories exhibited by many plume tracking organisms, suggesting that perhaps flow estimation is a secondary driver of their trajectory structure.

Food pleasure across nations: A comparison of the drivers between Chinese and Danish populations

Cross-cultural research with a focus on understanding food consumer behaviour is becoming increasingly relevant and important, not least because of the globalization of food markets. A better understanding of the relative importance of factors contributing to food pleasure could advance our understanding of different food behaviours.Two identical consumer surveys were conducted with a Chinese (n = 306) and a Danish sample (n = 280) to explore the importance of several drivers to food pleasure in each sample. Exploratory factor analyses were utilized for investigating underlying constructs of drivers of food pleasure. Most important drivers of food pleasure for each sample were investigated and a cross-cultural comparative analysis of main drivers of food pleasure was performed.Both samples found ‘Sensory-driven Pleasure’ to be most important for experienced food pleasure. In addition, the Danish sample had two secondary drivers of food-related pleasure; ‘Exploratory-driven Pleasure’ and ‘Confirming-driven Pleasure’. The Chinese sample had three secondary drivers of food pleasure: ‘Cognition-driven Pleasure’, ‘Curiosity-driven Pleasure’ and ‘Symbolic-driven Pleasure’. Thereby, the sensory-driven pleasure could be regarded the primary driver of food pleasure on a cross-cultural level, whereas secondary drivers seem to distinguish food-related pleasure in different cultures.These findings are relevant in several areas, as they provide new insights and knowledge of cultural differences in food choice and eating behaviour between China and Denmark, as well as contribute to the important field of cross-cultural research. This knowledge can support food researchers and food industry for a better understanding of what drives food pleasure, and ultimately food choice too.

IPCC's current conceptualization of ‘vulnerability’ needs more clarification for climate change vulnerability assessments

In this Short Communication, we raise the concern that the existing conceptualization of ‘vulnerability’, introduced in the IPCC Fifth Assessment Report (AR5), is not facilitative for standalone vulnerability assessments and that this conceptualization has not been well accepted by the vulnerability researchers. We identify three key reasons for low adoption of the AR5 conceptualization in climate change vulnerability assessments, and urge the IPCC Working Group II to clarify how the current conceptualization of ‘vulnerability’ can facilitate standalone climate change vulnerability assessments. We propose treating ‘exposure’ not only as a precondition for vulnerability but also as a secondary driver of vulnerability to capture the influence of differential exposure.

Introduction and Genetic Correction of Calreticulin Mutations in Human Hematopoietic Stem and Progenitor Cells Sheds Light on MPN Pathogenesis

Introduction:Recurrent mutations in calreticulin (CALR) are present in 70% to 80% of essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients without a JAK2 or MPL mutation. Despite recent advances in understanding mutant CALR, the detailed mechanisms are not fully elucidated, and current knowledge is mainly based on transgenic mouse models or human cancer cell lines. Thus, to more faithfully model MPN pathogenesis, we first aimed to introduce heterozygous type-1 and type-2 CALR mutations into healthy human hematopoietic stem and progenitor cells (HSPCs) via targeted CRISPR/Cas9-mediated gene knock-in (KI) and investigate its impact on HSPC function in vitro and in vivo. Second, we aimed to correct CALR mutations in patient-derived HSPCs to study their dependence on the initial driver event to exert an MPN phenotype.Methods:We used CRISPR/Cas9 to introduce heterozygous CALR mutations into the endogenous gene locus of healthy cord blood-derived HSPCs. Our approach is based on homologous recombination using DNA repair templates delivered by adeno-associated virus serotype 6 (AAV6). Briefly, Cas9-sgRNA ribonucleoprotein (RNP) was used to cut the DNA. Simultaneously AAV6, carrying either a mutation-bearing or a wildtype control cDNA, was co-delivered to allow for targeted in-frame integration. This way, mutant CALR remains under the control of the endogenous promoter. Concurrent integration of a fluorescent reporter downstream of the mutated exon, enabled purification and tracking of modified cells via flow cytometry. Purified CRISPR-modified HSPCs were used for in vitro collagen-based colony-forming assays, proliferation and differentiation assays in liquid culture, and intrafemoral transplantation into immunodeficient NSG mice to assess their pathogenic potential.Results:Our CRISPR/Cas9 KI strategy enabled us to efficiently generate and enrich for heterozygous CALR mutant human HSPCs. Modified cells harbor the mutation at the endogenous CALR locus with intact gene regulatory regions. Correct integration and transcript expression were confirmed on DNA and RNA level by sanger sequencing. Additionally, CALR mutant protein expression was confirmed via immunohistochemistry using a diagnostically approved mutant-specific antibody.Type-1 and type-2 CALR mutations led to TPO-independent growth of CD34 + HSPC-derived cells and a two-fold (p<0.01) increase of megakaryocyte colonies in collagen-based media compared to wildtype control KI. These findings were corroborated by significantly enhanced CD41 + CD42b + megakaryocyte formation of CALR mutant HSPCs upon liquid culture differentiation.When transplanted into sublethally irradiated immunodeficient NSG mice, CALR mutant HSPCs showed robust engraftment in the bone marrow with a myeloid lineage skewing, outcompetition of wildtype cells and increased formation of CALR mutant CD41 + megakaryocyte progenitors.To investigate, if removal of type-1 and type-2 CALR mutations can ameliorate MPNs, we utilized our KI strategy to correct both CALR mutations in MPN patient-derived HSPCs by replacing them with wildtype sequences. A successful correction was confirmed on DNA and RNA level and by the absence of mutant CALR protein. Opposite to the results from introducing CALR mutations, correcting the mutations led to a two-fold decrease in megakaryocyte colony formation. Interestingly this was only seen in ET and post-ET MF samples, whereas primary MF samples were unaffected, underscoring the importance of other secondary genetic driver events in the pathogenesis of primary MF.Conclusion:Our system allows us to investigate human MPN pathogenesis prospectively and shed light on the transforming mechanisms of mutant CALR in primary HSPCs. We could show that CALR mutations prime HSPCs toward the formation of platelet-producing megakaryocytes. Genetic correction of CALR mutations in MPN patient-derived HSPCs revealed a dependence on the oncogenic mutant CALR driver event in ET and post-ET MF patients, opening the possibility of an ex vivo gene correction approach to remove mutant CALR in patient-derived HSPCs . Lastly, since MPN patient-derived cells have notoriously low engraftment potential in mice, our CRISPR/Cas9-engineered CALR mutant model also provides a powerful new strategy to generate MPN xenotransplants with defined genotypes for the evaluation of novel therapies. DisclosuresGreinix: Celgene: Consultancy; Therakos: Consultancy; Takeda: Consultancy; Sanofi: Consultancy; Novartis: Consultancy. Sill: Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Zebisch: Novartis: Consultancy; AbbVie: Consultancy; Celgene: Consultancy, Honoraria. Reinisch: Celgene: Research Funding; Pfizer: Consultancy.

The ERK1/2 Regulator WNK2 Shows Differential Expression and Isoform Usage, Primarily Driven By Aberrant Methylation, in MYD88 Mutated Waldenström's Macroglobulinemia

MYD88 mutations (MYD88 MUT) are present in 95-97% of patients with Waldenström's Macroglobulinemia (WM). Transgenic mouse studies show that MYD88 MUT alone is insufficient to drive oncogenesis. We previously reported the occurrence of non-overlapping somatic mutations in either CXCR4 (CXCR4 MUT) or deletions in 6q (del6q) in MYD88 mutated (MYD88 MUT) WM patients, suggesting either event may serve as a secondary driver of WM oncogenesis. Intersecting the lists of genes differentially modulated by either CXCR4 MUT or del6q revealed WNK2 as a top hit (Guerrera ML et al, Haematologica 2018). WNK2 is a serine/threonine protein kinase that negatively regulates ERK1/2 activation and has known tumor suppressor function in several solid tumors, wherein its expression is primarily silenced by aberrant promoter methylation. ERK1/2 pathway plays an important pro-survival role, its activation is accompanied by the release of inflammatory cytokines and can mediate ibrutinib resistance in WM (Chen et al, Blood 2018). We therefore sought to investigate the expression of WNK2, and clarify the mechanisms underlying its aberrant expression by genomic subtypes in WM.To study the regulation of WNK2 gene expression, we analyzed our previously published RNA-Seq data (Hunter ZH et al, Blood 2016) and validated findings in 47 WM patients by RT-qPCR. Compared to healthy donor (HD) B and plasma cells (PC), we observed marked upregulation of WNK2 expression in bone marrow (BM) CD19-selected tumor cells from MYD88 MUTCXCR4 WT patients (p<0.0001). Conversely, WNK2 expression was silenced in tumor cells from MYD88 MUTCXCR4 MUT and MYD88 WTCXCR4 WT (p<0.001 vs HD PC) patients, with less pronounced suppression of WNK2 also observed in MYD88 MUTdel6q cases. Immunohistochemistry analysis on patient BM biopsies confirmed the findings observed at the mRNA level per patient genotype.To assess the impact of alternative splice variants on overall gene expression, we then studied the relative composition of the 16 documented isoforms (Figure 1). RNA-Seq showed a prevalence of protein-coding transcripts, particularly those coding for isoforms missing the ERK regulatory kinase domain, in MYD88 MUT vs MYD88 WT WM. By RT-PCR, we validated the preferential use of the protein-coding WNK2-208, WNK2-203 and WNK2-205 transcripts in 32 of 47 WM samples with detectable total WNK2 levels. Of those, WNK2-208 and WNK2-203 lack the region coding for the functional kinase domain. Analysis of known post-translational modification (PTM) sites annotated for the canonical isoform WNK2-201 in the 3 isoforms of interest demonstrated that C-terminal PTM sites are highly conserved across all isoforms even in the absence of the kinase domain, alluding to novel protein regulatory sites yet to be characterized.Analysis of CpG methylation using enhanced reduced representation bisulfite sequencing from 62 WM patients identified 3 clusters of differentially methylated CpG islands (CpGs) between MYD88 MUTCXCR4 WT and MYD88 MUTCXCR4 MUT patients. Three CpGs in the WNK2 promoter, four in intron 1 and one in intron 11 constituted clusters 1, 2 and 3, respectively (Figure 1). Compared to healthy donor memory B-cell and PC, we observed aberrant hypermethylation in cluster 1 in MYD88 MUTCXCR4 MUT and hypomethylation at a putative enhancer in cluster 2 in MYD88 MUTCXCR4 WT patients, while del6q cases showed a mixed methylation pattern. A higher degree of methylation, particularly in cluster 2, significantly correlated with reduction in total and transcript-specific WNK2 mRNA levels that affected expression of transcripts encoding for kinase domain-containing isoforms. Furthermore, we validated the differential methylation status of 3 of 4 methylated CpGs in cluster 2 in 10 patients, including MYD88 MUTCXCR4 WT, MYD88 MUTCXCR4 MUT and MYD88 MUTdel6q, and 3 MYD88 MUT (BCWM.1, TMD-8) and MYD88 WT (Ramos) cell lines by means of bisulfite PCR followed by Sanger sequencing. Taken together, our findings reveal that the ERK1/2 regulator WNK2 shows differential expression and isoform usage in distinct genomic subsets of MYD88 MUT WM; is primarily driven by aberrant methylation; and may serve as a key driver of disease progression in WM. [Display omitted] DisclosuresYang: Blueprint Medicines Corporations: Current Employment, Current holder of individual stocks in a privately-held company. Castillo: Abbvie: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy; Roche: Consultancy; TG Therapeutics: Research Funding. Treon: BeiGene: Consultancy, Research Funding; Eli Lily: Research Funding; Abbvie/Pharmacyclics: Consultancy, Research Funding.

1595 Instituting Rapid and Semi-rapid COVID-19 Testing Pathways to Facilitate Emergency Surgery

Abstract Aim Defining a patient’s COVID-19 status on admission is essential for optimised patient management, safe bed-placement, and flow across the hospital. Perioperative COVID-19 infection is associated with significantly poorer outcomes and may influence a patient's and/or surgeon's decision to proceed. Rapid PCR tests (1-2 hours) for COVID-19 remain the gold-standard, however most NHS Trust’s either do not have, or have severely limited access to such testing modalities. Our aim was to introduce a surgical triaging algorithm to conserve rapid testing for immediate surgery, whilst developing a semi-rapid pathway with results available in 12-15 hours for surgery within 24-48 hours. Method Using quality improvement methodology, based on a ‘PDSA’ model we introduced a surgical triaging algorithm. Testing options were categorised into rapid, semi-rapid or routine (24 hours). Defined outcomes, as well as primary and secondary drivers were identified. Both the pre-analytical and post-analytical testing pathways were characterised, concentrating on electronic requesting, laboratory transportation and reporting. Five ‘PDSA’ cycles were performed with immediate audit and feed-back to surgeons after each round. A vetting procedure was also introduced to improve compliance with requesting. Results Turn-around-times for COVID-19 PCR swabs at our institution improved from 23 hrs:13 minutes at baseline, to 9 hrs:38 minutes for semi-rapids, to &amp;lt; 2 hours for rapid swabs. Conclusions Adoption of a surgical triaging algorithm ensured prioritisation of rapid and semi-rapid COVID testing based on clinical need. This ensured optimised patient care, safe theatre and anaesthetic Infection Prevention and Control practices, as well as correct post-operative placement.

Quantifying Contributions of External Drivers to the Global Ionospheric State

AbstractTo advance our understanding of the global response of the ionospheric total electron content (TEC) to various external drivers, we apply entropy‐based information theory to quantify contributions of solar, interplanetary, and lower atmospheric drivers to the global ionospheric state described by the Global Ionospheric Map (GIM). By computing normalized transfer entropy on 18 years of GIM TEC, F10.7, solar wind, and lower atmospheric data, we obtain the predictive information transfer from the present drivers to the global ionospheric state at various future times. We find that the solar extreme ultraviolet (EUV) irradiance dominates the information transfer within 3 days into the future, while the lower atmospheric migrating tidal sources dominate beyond 3 days into the future. The maximum information transfer from individual drivers reveals the maximum contributions from the drivers to the global ionospheric state. Among all drivers considered, the lower atmospheric migrating tidal sources contribute most. The solar EUV irradiance and tropospheric deep convection are secondary drivers with comparable contributions at about half of the contribution from migrating tidal sources. The interplanetary driving contributes the least to the global ionospheric state during both geomagnetic storm and quiet time, even though the contribution from the interplanetary magnetic field can enhance four to six times during geomagnetic storm time than quiet time.

Histopathological, Ultrastructural, and Immunohistochemical Findings in Radial Longitudinal Deficiency: A Prospective, Observational Study

To report the histopathological, electron microscopic, and immunohistochemical findings of tissue samples obtained from patients with radial longitudinal deficiency (RLD) and investigate the contribution of abnormality in soft tissues as a secondary driver of deformity in RLD. Specimens from radial-sided muscles and tendons were obtained at the time of surgery (either radialization or centralization) from 14 patients with 16 limbs affected with Bayne type 3 and type 4 RLD. The specimens were evaluated using light microscopy, electron microscopy, and immunohistochemical examination. Among the 16 frozen muscle specimens, 6 (37%) showed normal muscle, while 10 (63%) showed the presence of atrophic fibers. The 6 cases with normal muscle showed no abnormality in fiber type distribution. Six patients showed predominance of type 1 muscle fibers. None of the specimens had myofibroblasts; 4 of 16 specimens had mast cells, and 9 of 16 specimens showed the presence of platelet derived growth factor-positive cells. Features of myofibroblasts (the presence of basal lamina, intercellular junctions, or pinocytic vesicles) were not identified in any specimen on electron microscopy. The histopathological, electron microscopic, and immunohistochemical findings, in particular the absence of myofibroblasts, in tissue samples obtained from patients with RLD, do not support the assumption of abnormality in soft tissues as a secondary driver of deformity in RLD. This study provides a preliminary insight into a possible role of soft tissues in the development of the deformity in RLD.

Diel and seasonal patterns of soil CO2 efflux in a temperate tidal marsh

Tidal marshes store large amounts of carbon; however, little is known about the patterns, magnitudes, and biophysical drivers that regulate CO2 efflux from these ecosystems. Due to harsh environmental conditions (e.g., flooding), it is difficult to measure continuous soil CO2 efflux in tidal marshes. These data are necessary to inform empirical and process-based models and to better quantify carbon budgets. We performed automated (30 min) and manual (bi-monthly) soil CO2 efflux measurements, for ~20 months, at two sites in a temperate tidal marsh: tall Spartina (TS; dominated by S. cynosuroides) and short Spartina (SS; dominated by S. alterniflora). These measurements were coupled with water quality, canopy spectral reflectance, and meteorological measurements. There were no consistent diel patterns of soil CO2 efflux, suggesting a decoupling of soil CO2 efflux with diel variations in temperature and tides (i.e., water level) showing a hysteresis effect. Mean soil CO2 efflux was significantly higher at SS (2.15 ± 1.60 μmol CO2 m−2 s−1) than at TS (0.55 ± 0.80 μmol CO2 m−2 s−1), highlighting distinct biogeochemical spatial variability. At the annual scale, air temperature explained >50% of the variability in soil CO2 efflux at both sites; and water level and salinity were secondary drivers of soil CO2 efflux at SS and TS, respectively. Annual soil CO2 efflux varied from 287-876 to 153-211 g C m−2 y−1 at SS and TS, respectively, but manual measurements underestimated the annual flux by <67% at SS and <23% at TS. These results suggest that measuring and modeling diel soil CO2 efflux variability in tidal marshes may be more challenging than previously expected and highlight large discrepancies between manual and automated soil CO2 efflux measurements. New technical approaches are needed to implement long-term automated measurements of soil CO2 efflux across wetlands to properly estimate the carbon balance of these ecosystems.

The Role of Flare‐Driven Ionospheric Electron Density Changes on the Doppler Flash Observed by SuperDARN HF Radars

AbstractTrans‐ionospheric high frequency (HF: 3–30 MHz) signals experience strong attenuation following a solar flare‐driven sudden ionospheric disturbance (SID). Solar flare‐driven HF absorption, referred to as short‐wave fadeout, is a well‐known impact of SIDs, but the initial Doppler frequency shift phenomena, also known as “Doppler flash” in the traveling radio wave is not well understood. This study seeks to advance our understanding of the initial impacts of solar flare‐driven SID using a physics‐based whole atmosphere model for a specific solar flare event. First, we demonstrate that the Doppler flash phenomenon observed by Super Dual Auroral Radar Network (SuperDARN) radars can be successfully reproduced using first‐principles based modeling. The output from the simulation is validated against SuperDARN line‐of‐sight Doppler velocity measurements. We then examine which region of the ionosphere, D, E, or F, makes the largest contribution to the Doppler flash. We also consider the relative contribution of change in refractive index through the ionospheric layers versus lowered reflection height. We find: (a) the model is able to reproduce radar observations with an root‐median‐squared‐error and a mean percentage error (δ) of 3.72 m/s and 0.67%, respectively; (b) the F‐region is the most significant contributor to the total Doppler flash (∼48%), 30% of which is contributed by the change in F‐region's refractive index, while the other ∼18% is due to change in ray reflection height. Our analysis shows lowering of the F‐region's ray reflection point is a secondary driver compared to the change in refractive index.

PD-0867 Development of a Radiotherapy Quality Assessment Tool

Purpose or Objective There is increasing focus on developing and implementing quality and service improvement methodology in healthcare practice with it recognised that these principles must be embedded in the governance framework and culture of services. Radiotherapy (RT) pathways are complex and multidisciplinary. This project aims to develop a quality assessment (QA) tool for evaluating operational/technical aspects of RT service within and across different departments. Materials and Methods A multidisciplinary team (MDT) scoping exercise was undertaken within a single large RT centre and theme analysis was cross referenced with associated literature and theories to inform the development of the QA tool. The tool was validated in three different clinical scenarios and the associated processes were refined through MDT inquiries. There as 5 steps to completing the tool as a collaborative MDT. 1. Framing the question Questions can be categorised into two categories. Category 1: Direct comparison between the same service/pathway in two different departments. Category 2: Comparison of two alternative pathways in a single department. 2. Identifying drivers Primary and secondary drivers for answering the given question should be discussed and noted to allow for considered evaluation of scoring following completion of the tool 3. Scoping Review of the metrics/measures of quality and efficiency/resource for different aspects of the pathway should be identified under the headings outlined below. - Structure: Consider the attributes of the service/ pathway such as e.g. Staff to patient ratios, Skill Mix/Pay banding - Process: Consider how each procedure/system of work interacts in order to achieve the outcomes as defined by clinical policies and procedures. - Outcome: Measures should consider the impact on potential endpoints. 4. Scoring Each aspects of the pathway identified under the different headings is discussed and scored according to the scoring matrix for both the quality and efficiency/productivity (table 1). Only a quality score is applied to the outcomes. (Table presented.)ale Results) Clinical example 1 (COVID initiative): telephone vs face to face on treatment consultation Completing the QA tool identified not only that there were comparable outcomes with significant efficiency and potential quality improvement via telephone consultation but also highlighted where enhancement of other areas of the patient pathway were needed. This mitigated patient care risk to allow benefits from this service improvement to be realised.) Clinical example 2: Treatment verification for prostate SABR CBCT vs Fiducial Utilising the tool in this clinical example identified key lines of enquiry from both a clinical and technical perspective and promoted an objective evidence-based approach to evaluating the necessities of fiducials in the context of prostate imaged guided radiotherapy. A pathway change was implemented. Clinical example 3: Eclipse pathway vs Pinnacle pathway The tool was implemented following an MDT incident review meeting. Figure1 shows the visual output after completing the tool scoring comparing the two palliative RT pathways utilising two different RT planning systems. Points 1,2 relate to structure, 3,4,5 to process and 6 the outcome. It was evident that despite the outcome of the two pathways being comparable, pathway 2 represented a quality improvement not only in quality including risk but also efficiency features of the pathway and was implemented in practice. $Φg Conclusion The QA tool can support collaborative service improvements and enhance the governance process within RT services. Analysing the themes of user feedback from those who were involved in the piloting of the QA tool indicated that the tool was supportive in, • Objective independent discussion. • Encouraging collaboration between different professions. • Promoting an evidence-based approach across all aspects of the pathway. • Provided a useful output for reporting within governance process. • Future work has been planned to valid te the tool in a multicentre setting. Future work has been planned to validate the tool in a multicentre setting.

Proton-conducting Ceramic Fuel Cells for Co-Producing Electricity and Fuel – A Design for Manufacture and Assembly (DFMA) Analysis

This work develops preliminary design for manufacture and assembly (DFMA) models of a novel, proton-conducting, anode-supported ceramic electrochemical cell for co-producing electricity and fuels simultaneously. These DFMA models can then be used to estimated future, expected costs incorporating the novel cell design under various manufacturing production scenarios. The cell electrochemically coverts oxygen (O2) in air and methane (CH4) fuel (the primary constituent of natural gas) into electricity, water, and higher-order hydrocarbons, such as ethane (C2H6). To do this, the cell integrates a methane coupling catalyst into the anode and thereby co-produces ethane (C2H6) and hydrogen (H2) at the anode. The ethane can then be converted into other fuels. The cell is part of a joint R&D effort by Argonne National Laboratory (ANL) and the Illinois Institute of Technology (IIT). The cell’s current technology readiness level (TRL) is about a one (1), i.e. laboratory-scale demonstration of the fundamental concept.Approach:Gaia Energy Research Institute (Gaia) collaborates closely with ANL and IIT to develop the DFMA models for this novel cell design. Gaia works closely with ANL and IIT to identify and analyze key electrochemical cell engineering performance data. Gaia then develops and deploys custom DFMA computer models and data sets. DFMA models center around the electrolyte-electrode assembly (EEA), or the ‘heart’ of the electrochemical cell, where the anode and cathode half-reactions occur. Gaia first develops a specific physical embodiment of the novel cell, then the cell’s bill of materials (BOM), and finally cost estimates for the electrochemical cell, fuel cell stack, and full-scale stationary fuel cell system. Gaia follows this methodology:1. Develop a specific design that physically embodies the EEA concept;2. Develop the EEA’s BOM to specify quantities of components and materials used;3. Identify, for all key materials, price quotes from one or more manufacturers;4. Calculate the minimum costs for the EEA based on materials costs alone;5. Ascertain the EEA’s primary cost drivers;6. Quantify the uninstalled capital costs for a full-size fuel cell stack and stationary fuel cell system incorporating the novel cell design.With the exception of the EEA, other parts of the fuel cell, stack, and system were assumed to be somewhat similar in design to more traditional stationary solid oxide fuel cell (SOFC) systems. Capital costs for the novel stack design were scaled linearly with stack power density. This work estimates stack and system costs for a 100 kWe net electric stack mass-produced at a rate of 50,000 systems per year.Results:Model results indicate that the fuel cell stack subsystem will cost about $478/kW and the entire fuel cell system will cost about $597/kW, including all BOP components. These stack costs are roughly 74% higher than a ‘plain vanilla’ SOFC subsystem, analyzed by the author for DOE in a prior analysis. These system costs are roughly 48% higher than the same ‘plain vanilla’ SOFC system previously analyzed. At the same time, these cost estimates are well below the DOE ARPA-E program goal of < $2,000/kW.Gaia observed an order of magnitude difference in price quotes for several of the specialty ceramic materials investigated. Price quotes from Praxair Specialty Ceramics were approximately double those of Trans-Tech Inc. The reasons cited for the extreme price differential were different manufacturing methods, specifically a chemical co-processing approach for Praxair and a solid-state material manufacturing process (SSMP) for Trans-Tech Inc. The pros and cons of each manufacturing approach are discussed in greater detail in this talk. This analysis assumes that SSMP is used with no degradation in cell performance and bases subsequent cost estimates solely on prices from Trans-Tech Inc., and not Praxair, at ANL’s request.The primary cost driver for the EEA appears to be the BZY-NiO anode substrate. The BZY and NiO anode substrate material is estimated to cost either 2.88 cents/cm2 [based on price quotes for BZY from TransTech Inc.] or 16.40 cents/cm2 [based on price quotes from Praxair Specialty Ceramics]. If the lower BZY cost estimate is taken based on price quotes from Trans-Tech Inc., 52% of the cost derives from the BZY. If the higher BZY cost estimate is taken based on price quotes from Praxair Specialty Ceramics Inc., 92% of the cost derives from the BZY. The secondary cost driver for the EEA appears to be the anode catalyst. The catalyst material is estimated to cost 2.45 cents/cm2. 94% of its cost is due to the material cost of the platinum. The EEA is estimated to cost 5.56 cents/cm2 or $278/kW of gross electric power from the cell or stack.

Food availability and temperature optima shaped functional composition of chironomid assemblages during the Late Glacial–Holocene transition in Northern Europe

Non-biting midges (Chironomidae) are the most diverse and abundant invertebrate group in boreal lakes and are strongly responsive to climate change, thus they are a valuable palaeoecological proxy for studying aquatic biodiversity response in the face of climate change. Here, we aim to decipher the influence of climate-induced changes on temporal patterns in chironomid assemblages. We apply a novel approach combining traditional taxon-based analysis and species-trait framework to subfossil chironomid assemblages in a sediment core covering the Late Glacial–Holocene transition in Northern Europe. We produce pollen-based July and January temperature reconstructions to characterize past climate fluctuations that show a distinct Early Holocene warming for continuous 1700 years with considerably greater warming in winter (ca. 10 °C) than summer (ca. 4 °C) temperature. Overall, chironomid taxonomic changes were mainly induced by the temperature tolerances and optima of species, as temporal dynamics showed agreement with temperature reconstructions. Our results suggest that vegetation dynamics could also play a role in structuring chironomid assemblages by selecting taxa with the highest ability to exploit available food resources, thus potentially confounding chironomid-based summer climate reconstructions. We demonstrate that the study of the hidden chironomid functional composition could help to identify secondary drivers and thus strengthen the reliability of climate reconstruction based on subfossil chironomids.

Mass mortality of pen shell Atrina maura (Bivalvia: Pinnidae) due to abrupt population increase of tunicate (Distaplia sp.) in a subtropical bay, Mexico

The present study analyses the coverage of epibiont Distaplia cf. stylifera (Ascidiacea: Holozoidae) and five environmental variables (Sal, SST, DO, sea surface Chl-a concentration and pH) as potential factors to explain a mass mortality event in a restored population of the pen shell Atrina maura (Bivalvia: Pinnidae) in a subtropical bay of the Gulf of California, Mexico. Annual autumn surveys in 2015, 2016 and 2017 (Nov–Dec) and an additional summer survey in 2016 (Jun) showed that the tunicate was first observed at low densities in a few sampling sites during 2015 and rapidly expanded along the pen shell banks in 2016. Tunicate manual removal was carried out in two small areas during Sep-Nov 2016 and Jan–Mar 2017. The mass mortalities of A. maura detected in 2016 and 2017 resulted in a high economic loss for regional fishers. A Generalised additive model (GAM) indicated that the substrate provided by A. maura was the only significant factor associated to the rapid expansion (measured as the proportion of coverage) of D. cf. stylifera. Paradoxically, the recovery success in the A. maura population increased substrate availability for the tunicate epibiont, facilitating an abrupt and fast colonisation process on the pen shell banks, resulting in A. maura mass mortality events in 2016 and 2017. Our model predicts that D. cf. stylifera coverage effects begin to occur when the density of A. maura is > 47 inds./250 m2. A second GAM demonstrated that the main driver of A. maura mortality was ascidian coverage, and salinity, SST and DO were secondary driver factors. We concluded that the density of dead A. maura increases when the coverage of D. cf. stylifera is >8%, salinity >37.3 PSU, SST <26.9 °C and DO > 5.06 mg O2/L. Early harvesting of A. maura to decrease substrate availability at the first signs of D. cf. stylifera population growth can avoid significant economic losses in the future.