Large Variations Research Articles

Satellite-Based Estimation of Nitrous Oxide Concentration and Emission in a Large Estuary.

Estuaries are nitrous oxide (N2O) emission hotspots and play an important role in the global N2O budget. However, the large spatiotemporal variability of emission in complex estuary environments is challenging for large-scale monitoring and budget quantification. This study retrieved water environmental variables associated with N2O cycling based on satellite imagery and developed a machine learning model for N2O concentration estimations. The model was adopted in China's Pearl River Estuary to assess spatiotemporal N2O dynamics as well as annual total diffusive emissions between 2003 and 2022. Results showed significant variability in spatiotemporal N2O concentrations and emissions. The annual total diffusive emission ranged from 0.76 to 1.09 Gg (0.95 Gg average) over the past two decades. Additionally, results showed significant seasonal variability with the highest contribution during spring (31 ± 3%) and lowest contribution during autumn (21 ± 1%). Meanwhile, emissions peaked at river outlets and decreased in an outward direction. Spatial hotspots contributed 43% of the total emission while covering 20% of the total area. Finally, SHapley Additive exPlanations (SHAP) was adopted, which showed that temperature and salinity, followed by dissolved inorganic nitrogen, were key input features influencing estuarine N2O estimations. This study demonstrates the potential of remote sensing for the estimation of estuarine emission estimations.

The Distribution and Seasonality of Per- and Polyfluoroalkyl Substances (PFAS) in the Vertical Water Column of a Stratified Eutrophic Freshwater Lake

The vertical distribution and potential variability of Per- and Polyfluoroalkyl substances (PFAS) in the water column of lacustrine systems is important to know for sampling and monitoring purposes, but could also relate to details of their fate, transport, and distribution. In this study, the water column of a eutrophic freshwater lake (Lake Monona, Madison, WI, USA) was sampled vertically for PFAS during summer stratification at several depths (surface microlayer to 1 m from the bottom) and then monitored at four dates and three depths the following year to assess seasonality. PFAS concentration did not exhibit vertical stratification or large variability in the water column. However, seasonal variation in PFAS concentration was detected, as well as an increase in PFAS concentration related to drought conditions. This study suggests that a surface water grab sample may be a sufficient representative of the water column for the basic monitoring of PFAS. But a single sample during the year may not provide a complete understanding of the lake, and multiple samples should be taken to capture and understand important seasonal events.

Large Variations in Phenylalanine Concentrations Associate Adverse Cardiac Remodelling in Adult Patients With Phenylketonuria-A Long-Term CMR Study.

Despite a phenylalanine (Phe) restrictive diet, most adult patients with 'classical' phenylketonuria (PKU) maintain life-long Phe concentrations above the normal range and receive tyrosine (Tyr) and protein-enriched diets to maintain acceptable concentrations and ensure normal development. While these interventions are highly successful in preventing adverse neuropsychiatric complications, their long- term consequences are incompletely explored. We observed early cardiomyopathic characteristics and associated hemodynamic changes in adult PKU patients and present here the results of a longitudinal evaluation of cardiac phenotype. Fifteen adult patients with PKU (age: 39.8 ± 8.1 years, 9 males and 6 females) underwent a comprehensive follow-up cardiac magnetic resonance (CMR) imaging assessment after a mean follow-up interval of 8.3 ± 0.3 years from the initial baseline visit. The CMR protocol included left (LV) and right (RV) ventricular and left atrial (LA) volumetric assessment, LV parametric mapping (precontrast and postcontrast T1 and T2 maps, extracellular volume [ECV]), multilayer LV myocardial strain, systolic and diastolic hemodynamic forces and RV and LA strain and aortic distensibility evaluation. Plasma concentrations of Phe, tyrosine (Tyr) and other biochemical markers of disease were retrospectively collected. For comparison, a group of 20 matched control subjects undergoing an identical CMR protocol was included. On average, the LV end-diastolic volume (EDV) (158 ± 29 vs. 143 ± 29 mL, p = 0.013) and end-systolic volume (ESV) (68 ± 18 vs. 62 ± 18 mL, p = 0.011) were lower at follow-up. In contrast, LV mass (LVM) (72 ± 25 vs. 82 ± 29 g, p < 0.001) and the ratio LVM/EDV (0.46 ± 0.12 vs. 0.58 ± 0.23 g/mL, p = 0.005) were increased, and T1 times were longer (940 ± 42 vs. 1010 ± 35 ms, p < 0.001). LV EF (57 ± 6 vs. 57 ± 7%, p = 0.90), longitudinal (GLS) and circumferential (GCS) systolic strain remained unchanged, but early diastolic hemodynamic (HD) forces were more markedly negative (-19.4 ± 7.0 vs. -26.5 ± 12.2%, p = 0.012), while LA strain 43.8 ± 11.3 vs. 37.3 ± 9.6%, p = 0.031) and aortic distensibility (6.38 ± 1.75 vs. 5.21 ± 1.17 10-3 mmHg-1, p = 0.008) decreased at follow-up. Compared with controls, PKU patients maintain reduced systolic function with lower LV EF and impaired GCS and have more markedly negative early diastolic HD pressures. A higher decrease in Phe concentration (ΔPhe) was associated with longer T1 times, ΔT1 (β = -0.78, p < 0.001), increased ECV, ΔECV (β = -0.61, p = 0.016) and a decrease in systolic function, ΔEF (β = 0.61, p = 0.017). In contrast, variations in Tyr concentrations did not affect the cardiac phenotype. At long-term follow-up, a marked drop in Phe plasma concentration was associated with detrimental cardiac remodelling consisting of decreased LV systolic function and increased diffuse fibrosis, in PKU patients. These new data prompt further investigation into the effects of large Phe variability over time and underline the usefulness of periodic cardiovascular assessment in adults with PKU.

Transcranial direct current stimulation alleviates the pain severity in people suffering from knee osteoarthritis: a systematic review and meta-analysis.

Considerable research has shown the benefits of transcranial direct current stimulation (tDCS) for the alleviation of pain associated with knee osteoarthritis (KOA). Still, a large variance in study protocols and observations across publications exists. We here thus completed a systematic review and meta-analysis to comprehensively and quantitatively characterize the effects of tDCS on KOA-related pain. A search strategy based on the Population, Intervention, Comparison, Outcome, and Study design (PICOS) principle was used to obtain the publications in 7 databases. Studies exploring the effects of tDCS on KOA-related pain were screened, and eligible studies were included. Ten studies of 518 participants using Visual Analogue Scale or Numeric Rating Scale to assess pain were included in the systematic review, and 9 of them were included in meta-analysis. The quality of these studies was good. Compared to control, tDCS induced significant short-term improvements in KOA-related pain with medium heterogeneity (standardized mean difference [SMD] = -0.91, 95% confidence interval [-1.24, -0.58], P < 0.001, I2 = 61%). Subgroup analyses showed that both home-based (SMD = -1.32, 95% CI [-1.65, -0.99], P < 0.001, I 2 = 0%) and laboratory-based intervention (SMD = -0.66, 95% CI [-0.99, -0.33], P < 0.001, I 2 = 40%) with at least 5 sessions per week (SMD = -1.02, 95% CI [-1.41, -0.64], P < 0.001, I 2 = 65%) and/or with a total number of at least 10 sessions (SMD = -1.12, 95% CI [-1.51, -0.74], P < 0.001, I 2 = 59%) can induce maximum benefits for the alleviation of KOA-related pain. The results here showed that tDCS is of great promise to alleviate KOA-related pain. Still, future studies with more rigorous design are needed to confirm the observations from this work, which can ultimately help the determination of appropriate intervention protocol that can maximize such benefits.

Differential prevalence of arsenic speciation in the kelps Laminaria digitata and L. hyperborea.

Large variability in highly toxic inorganic arsenic (iAs) has previously been reported for the kelp Laminaria digitata. This study aimed to compare iAs concentrations in two morphologically similar kelps species (L. digitata and L. hyperborea). Both species contained similarly high total arsenic concentrations. However, whilst L. hyperborea contained only trace levels of iAs (0.363±0.161mg/kg), iAs constituted the majority of arsenic species in L. digitata (61.6±18.7mg/kg). Since the identification of iAs relies on retention time of the arsenic species, co-elution of any other organoarsenicals was checked by determination of arsenosugars using HPLC-ICPMS and ESI-HR-MS. Additionally, hydride generation ICP-MS gave comparable results to HPLC-ICPMS analyses. Overall, given the previously observed variability in iAs within and across kelp biomass, and the possibility of commercial processing of mixed-species kelp biomass that may include L. digitata, it may be advisable to verify iAs concentration regularly in seaweed batches destined for any application that exposes humans or animals to risks associated with As toxicity.

The 2024 American Association for Thoracic Surgery expert consensus document: Current standards in donor lung procurement and preservation.

Donor lung procurement and preservation is critical for lung transplantationsuccess. Unfortunately, the large variability in techniques impacts organ utilization rates and transplantation outcomes. Compounding this variation, recent developments in cold static preservation and new technological advances with machine perfusion have increased the complexity of the procedure. The objective of the American Association for Thoracic Surgery (AATS) Clinical Practice Standards Committee (CPSC) expert panel was to make evidence-based recommendations for best practices in donor lung procurement and preservationbased on review of the existing literature. The AATS CPSC assembled an expert panel of 16 lung transplantation surgeons from 14 centers who developed a consensus document of recommendations. The panel was divided into 7 subgroups covering (1) intraoperative donor assessment, (2) surgical techniques, (3) ex situ static lung preservation methods, (4) hypothermic preservation, (5) normothermic exvivo lung perfusion (EVLP), (6) donation after circulatory death (DCD) and normothermic regional perfusion, and (7) donor management centers, organ assessment centers, and third-party procurementteams. Following a focused literature review, each subgroup formulated recommendation statements for each subtopic, which were reviewed and further refined using a Delphi process until a 75% consensus was achieved on each final statement by the voting group. The expert panel achieved consensus on 34 recommendations for current best practices in donor lung procurement and preservation both in brain-dead as well as DCD donation. The use of new methods of cold preservation, the role of EVLP, and DCD with and without concomitant heart donation are described in detail. Consistent and best practices in donor lung procurement and preservationare critical to improve both lung transplantation numbers as well as recipient outcomes. The recommendations described here provide guidance forprofessionals involved in the care of patients with end-stage lung disease considered for transplantation.

Path integral molecular dynamics approximations of quantum canonical observables

Mean-field molecular dynamics based on path integrals is used to approximate canonical quantum observables for particle systems consisting of nuclei and electrons. A computational bottleneck is the Monte Carlo sampling from the Gibbs density of the electron operator, which due to the fermion sign problem has a computational complexity that scales exponentially with the number of electrons. In this work, we construct an algorithm that approximates the mean-field Hamiltonian by path integrals for fermions. The algorithm is based on the determinant of a matrix with components based on Brownian bridges connecting permuted electron coordinates. The computational work for n electrons is O(n3), which reduces the computational complexity associated with the fermion sign problem. We analyze a bias resulting from this approximation and provide a rough computational error indicator. It remains to rigorously explain the surprisingly high accuracy for high temperatures. The method becomes infeasible at low temperatures due to a large sample variance.

Dynamic in vivo monitoring of granum structural changes of Ctenanthe setosa (Roscoe) Eichler during drought stress and subsequent recovery.

Investigating the effects of drought stress and subsequent recovery on the structure and function of chloroplasts is essential to understanding how plants adapt to environmental stressors. We investigated Ctenanthe setosa (Roscoe) Eichler, an ornamental plant that can tolerate prolonged drought periods (40 and 49 days of water withdrawal). Conventional biochemical, biophysical, physiological and (ultra)structural methods combined for the first time in a higher plant with in vivo small-angle neutron scattering (SANS) were used to characterize the alterations induced by drought stress and subsequent recovery. Upon drought stress, no significant changes occurred in the chloroplast ultrastructure, chlorophyll content, 77K fluorescence emission spectra and maximal quantum efficiency of PSII (Qy dark), but the actual quantum efficiency of PSII (Qy light) decreased, the amounts of PSI-LHCII complexes and PSII monomers declined, and that of PSII supercomplexes increased. Thickness of the leaf and of the adaxial hypodermis, chloroplast length and granum repeat distance (RD) values decreased upon drought stress, as shown by light microscopy and SANS, respectively. Because of the very slight (nm-range) changes in RD values, the large biological variability (significant differences in RD values among the leaves and studied leaf regions) and the invasive sampling required for this method, transmission electron microscopy (TEM) hardly showed significant differences. On the other side, in situ SANS analyses provided a unique insight in vivo into the fast structural recovery of the granum structure of drought-stressed leaves, which happened already 18 h after re-watering, while functional and biochemical recovery took place on a longer time scale.

Heavy Mineral Analysis and Characterization of Ilmenites from the Beach Sands of Central West Coast of India

ABSTRACT Studies on heavy minerals from the estuarine beaches of Kali and Gangavali River, Central West Coast of India were conducted to understand the abundance of heavy minerals and their characterization. Higher concentrations of heavy minerals were found during monsoon followed by pre- and post-monsoon seasons. Within the sub-environments of the studied beaches, the backshore has a higher abundance compared to berm zone. The estuarine beaches of the Gangavali River show higher heavy mineral concentrations compared to the Kali estuarine beaches. Quantitative heavy mineral studies indicated that ilmenite is the dominant mineral present in the study area and shows a large spatio-temporal variability in their concentration. Ilmenites are highly altered and show three stages of alterations viz., pseudoilmenite, pseudorutile and leucoxene which indicates a progressive alteration process in the natural sedimentary environment that is attributed to the leaching of iron along with other oxides from the ilmenite lattice. The ilmenite abundance in the beach sands and their characteristics suggest a promising source for industrial minerals and have the potential for future exploitation.

Crater Dimensions on the Dwarf Planets

Abstract The icy dwarf planets of Pluto, Charon, and Ceres provide important geologic comparisons for each other as they possess similar gravities and experience impacts of similar velocities compared to larger planets and moons. Differences in their impact craters can therefore be attributed to differences in the impactor and/or target compositions. Craters on Ceres show taller rims than craters on Charon, but comparable internal crater dimensions (depth, wall slope, and peak size). It is possible that the non-ice component of the Ceres crust provides additional strength to this outer portion of the crater, maintaining less rim collapse during the modification stage of crater formation, while the warmer central crater region is controlled by the weakness of the icy component. The spreads in depth-to-diameter ratio and wall-slope values for the Pluto data set are not clearly related to preservation state, suggesting that fresh craters on Pluto possess a large variance in these crater dimensions compared to Charon. This could be due to the geologically diverse terrains and depositional histories at different latitudes and longitudes of Pluto. These provide different target properties for each impact, so that even pristine impact craters on Pluto could display a wide range in depths and wall slopes based on the different strength of the target in each area.

Brazilian Amazon Coast is an essential habitat for threatened and evolutionarily distinct sharks and rays

Despite the high proportion of endangered species of elasmobranchs occurring in coastal areas subjected to intense fishing pressure, most of the existing habitat use information applies to pelagic species. Recent research efforts have substantially increased the information available on the habitat use of overlooked and often data deficient species. Here, we use vertebrae microchemistry data to study the habitat use patterns of four species of threatened sharks and two species of stingrays occurring in the Brazilian Amazon Coast (BAC). We obtained vertebrae samples from specimens sold in fish markets along the entire BAC area and analyze element:Ca ratios for four elements: Mg, Mn, Sr, and Ba. Our results demonstrate that most species likely complete their entire life cycle in the same region, with little to no use of freshwater habitats, and sympatric occurrence of neonates, juveniles, and adult life stages. The wingfin stingray, the only benthic-restricted species analyzed, differed substantially from all other species, with strong reliance on estuarine areas. The scalloped hammerhead has the largest variability in chemical trace elements, suggesting the use of habitats with wide variations. American cownose ray, daggernose, shovelbill, and smalleye hammerhead sharks showed strong reliance on the same type of habitat throughout their ontogenetic development. Our findings underscore the importance of the BAC as an Essential Fish Habitat for these species, a critical area for improved fisheries management given the widespread population declines and historical overfishing, and the danger of proposed oil exploration in the area can pose to its elasmobranch populations.

Vascular health and exercise in females throughout the lifespan: Exploring puberty, pregnancy and menopause.

This narrative review highlights the impact of exercise on vascular health in females over the lifespan with an emphasis on puberty, pregnancy and menopause. These events encompass substantial changes in sex hormone levels, particularly oestrogens and progesterone. They are also accompanied by distinct adaptations of the central, peripheral and cerebral vasculature. Regular exercise is an effective mechanism to reduce vascular risk in females of all ages, especially for those at higher risk for vascular disorders. However, there are large variabilities in the vascular adaptations to exercise in females that may be related to circulating sex hormone levels. In addition, exogenous hormones, such as oral contraceptives taken after puberty or hormonal replacement therapy taken to mitigate symptoms of menopause, may interact with exercise-induced changes in vascular function. We highlight how more research is needed to understand the optimal exercise interventions to promote vascular health in females across the lifespan, especially during times of hormonal transition.

Multi-session tDCS over the posterior parietal cortex and associative memory.

Associative memory (AM) plays a crucial role in our ability to link disparate elements of our experiences, yet it is especially vulnerable to age-related decline and pathological conditions. Non-invasive brain stimulation (NIBS), particularly transcranial direct current stimulation (tDCS), has been investigated as a potential intervention to enhance cognitive functions, including AM. Previous tDCS studies yielded inconsistent results, often due to variations in stimulation sites and protocols. Nonetheless, enough evidence suggests that tDCS over the posterior parietal cortex (PPC) can improve AM performance. This study aimed to investigate the cumulative effects of multiple anodal tDCS over the PPC on AM performance alongside item memory and verbal fluency. In a randomized sham-controlled trial, 59 healthy young adults were assigned to either anodal or sham stimulation group, receiving tDCS (1.5 mA, for 20 minutes, at P3) over three consecutive days. Memory performance was assessed at four timepoints: pretest, immediately after the first session, posttest (Day 5), and follow-up (Day 9). Although tDCS was well tolerated, the anticipated enhancement of memory performance was not observed. We interpret these findings in the light of methodological considerations and propose potential explanations for the observed results emphasizing the large between-participants variability in memory performance as a significant factor that may have hindered the detection of tDCS effects.

Accurate estimation of interobserver variability in echocardiography segmentation measured from 35 experts and impact on derived clinical metrics

Abstract Introduction The delineation of cardiac structures is crucial to the analysis of echocardiography images and a prerequisite for the calculation of clinical metrics derived from heart chamber areas and volumes. Nevertheless, significant interobserver variability exists due to anatomical variability and echocardiography image quality, leading to discrepancies in endocardial border tracing [1]. Estimations of interobserver variability reported in the literature are based on measurements from a reduced number of annotations per sample [2]. Purpose This work aims to elaborate on previous interobserver variability studies presented in the literature to improve the accuracy and robustness of the estimations by considering (1) a large cohort of annotators and (2) a controlled environment, where the interobserver variability is isolated from other sources of variability, such as image acquisition, cardiac cycle selection or labelling method. Methods A group of 35 experienced sonographers independently delineated the heart chambers at end-systole (ES) and end-diastole (ED) in apical 4-chamber (A4C) and 2-chamber (A2C) views from a cohort of 10 patients (median age 72, IQR: 52-77; predominantly male, 70%), resulting in a total of 120 corresponding annotations per sonographer. The ES and ED frames were preselected by a clinical committee for each sequence to remove this source of variability. Segmentations of each sonographer were used to derive the area of the heart chambers, along with several clinical metrics routinely used to assess cardiac morphology and function. Variability was quantified via relative standard deviation (RSD) and intraclass correlation coefficient (ICC). Results The analysis confirmed a large interobserver variability, with a global RSD of 15.4±5.2% and ICC of 0.89 in area (Figure 1). Variability was significantly higher at ES phase (p&amp;lt;0.001) and in A2C view (p=0.02). No significant differences were found across heart chambers. The annotation variability directly affected the calculation of clinical metrics, leading to particularly large RSD values for those metrics derived from multiple annotations (Figure 2). The variability of left ventricular ejection fraction (LVEF) was 16.0±3.4%, in line with the literature [3]. However, the LVEF ICC was highly compromised (0.187), suggesting that the interobserver variability is larger than the variability of the metric itself. This raises concerns about the use of LVEF derived from manual segmentation as a robust diagnostic reference [4]. These findings argue the need for enhanced standardization protocols and a swift towards automated annotation that mitigate this variability, as evidenced in the EchoNet trial [5]. Conclusion This study accurately evaluates the echocardiography segmentation interobserver variability and its impact on clinical metrics. The findings confirm a large variability and highlight the need to mitigate it, ultimately improving diagnostic assessment.

P-50. Mpox Vaccine Uptake Among Sexual and Gender Minority Veterans With and Without HIV in a Nationwide US Veteran Cohort

Abstract Background Sexual and gender minorities (SGM) and people with HIV have been disproportionately affected by the Mpox pandemic. Vaccination is recommended for those who may be at an increased risk. We examined the uptake of Mpox vaccine nationally in the Veterans Health Administration (VHA) among SGM Veterans and reported on disparities across groups. Methods We queried VHA’s national database to identify Veterans whose sexual orientation is recorded as lesbian, gay, bisexual or queer (LGBQ+) and gender identity as transgender woman (TGW)/man (TGM), non-binary or another gender (except cisgender) [transgender or gender diverse (TGD)] as of April 2024. Birth sex male LGBQ+ and TGD Veterans of both birth sexes were included in the cohort, stratified by age, race/ethnicity and HIV status. Within these cohorts we quantified receipt of JYNNEOS vaccine in the VHA starting 2022. Results Among the 42,434 males who identify as LGBQ+, 4759 (11.2%) had received at least one dose of the JYNNEOS vaccine; of these, 74% completed the series. There were large variabilities in vaccine uptake among LGBQ+ males by age: the 19-29 cohort had the lowest uptake at 5.2% and lowest series completion rate at 58.1% while the 50-59 age group had the highest uptake at 15.6% (Figure 1). Among racial groups, Asian LGBQ+ males had the highest uptake at 19.3%, and Whites had the lowest uptake at 9.4% (Figure 2). Black and Hispanic LGBQ+ males had better than average uptake at 14.7% and 15.6% respectively. Among 111,338 Veterans who identify as TGD, only 138 (1.2%) had received at least one dose by the end of observation period. Among these, TGW had the highest number of persons vaccinated (n=73) but non-binary Veterans had highest rate at 2.6% (Figure 3). Those with HIV were much more likely to have received at least one dose of the vaccine compared to those without (LGBQ+ males 25.5% vs. 7.6%; TGD 15.1% vs. 1%) (Figure 4). Conclusion TGD Veterans were much less likely to have received Mpox vaccination in the VHA compared to LGBQ+ males, with HIV status being the strongest predictor of vaccination in both groups. While the overall rates of Mpox vaccination appear lower in the VHA compared to general population, we did not see racial disparities that have been reported in Blacks but observed age related differences. Disclosures All Authors: No reported disclosures

Artificial intelligence for automatic echocardiography image view detection and left ventricle segmentation and ejection fraction prediction

Abstract Background Left-ventricular (LV) border segmentation is key to assess LV size and function. Current assessment has relatively large inter-observer variability, possibly impacting patients care. Artificial intelligence (AI) may permit faster and more reproducible assessment, possibly suitable to be used by non-experts. Purpose To train and test AI algorithms for (i) the identification of views, (ii) the segmentation of the LV in 2, 3 and 4-chamber views, and (iii) the computation of LV ejection fraction (EF). Methods Fifteen thousand echocardiography studies acquired in the Vall d’Hebron University Hospital (VH) for patients care were retrieved and anonymized. LV wall was identified via commercial clinical software in 619 videos with 2-, 3- and 4-chamber views (14082 frames) and 3 masks were created: LV cavity (within endocardial border), overall LV (within epicardial border) and LV wall. Annotated frames were split into independent training (465 videos) and testing (154) sets and performances were evaluated in terms of DICE score. End-diastolic and end-systolic LV volumes of 4-chamber views were identified and used to compute LV EF, which was compared with clinical reports in 488 patients. An external validation on CAMUS dataset was performed. Results A total of 6831 videos from 488 VH subjects were available for this analysis (Table 1). AI model identified image views with high accuracy (93%). AI performance on the segmentation of the LV cavity, overall LV and LV wall were satisfactory in 2- (0,86[0,79;0,90], 0,91[0,86;0,93], 0,79[0,74;0,83]), 3- (0,88[0,84;0,91], 0,91[0,90;0,93], 0,81[0,77;0,83]) and 4-chamber (0,90[0,86;0,93], 0,92[0,88;0,94], 0,82[0,79;0,85]) views. Segmentation performances were similar between sexes but were lower in case of atrial fibrillation and in images with low quality. In an external validation in 500 CAMUS patients performances were satisfactory, with DICE score of 0,91[0,87;0,94] and 0,80[0,73;0,84] for whole LV and LV cavity in 2 and 4-chamber views, respectively. In VH data EF predictions were in line with expected inter-observer reproducibility, with a good linear association (R=0.39, p&amp;lt;0.001) but remarkable underestimation (mean error = 12%). Models performed similarly in the external validation set, with a good linear association (R=0.31, p&amp;lt;0.001) and minimal underestimation (mean error = 2.2%). Conclusions AI models can identify echocardiography views, segment the LV in 2, 3 and 4-chamber views and use the segmentation to quantify EF. Care should be taken to avoid biases in AI performances, particularly in case of atrial fibrillation and limited image quality. Demographic and clinical information

Transformer-based neural speech decoding from surface and depth electrode signals

Objective.This study investigates speech decoding from neural signals captured by intracranial electrodes. Most prior works can only work with electrodes on a 2D grid (i.e. Electrocorticographic (ECoG) or ECoG array) and data from a single patient. We aim to design a deep-learning model architecture that can accommodate both surface ECoG and depth (stereotactic EEG or sEEG) electrodes. The architecture should allow training on data from multiple participants with large variability in electrode placements. The model should not have subject-specific layers and the trained model should perform well on participants unseen during training.Approach.We propose a novel transformer-based model architecture named SwinTW that can work with arbitrarily positioned electrodes by leveraging their 3D locations on the cortex rather than their positions on a 2D grid. We train subject-specific models using data from a single participant and multi-subject models exploiting data from multiple participants.Main results.The subject-specific models using only low-density 8 × 8 ECoG data achieved high decoding Pearson Correlation Coefficient with ground truth spectrogram (PCC = 0.817), overN= 43 participants, significantly outperforming our prior convolutional ResNet model and the 3D Swin transformer model. Incorporating additional strip, depth, and grid electrodes available in each participant (N= 39) led to further improvement (PCC = 0.838). For participants with only sEEG electrodes (N= 9), subject-specific models still enjoy comparable performance with an average PCC = 0.798. A single multi-subject model trained on ECoG data from 15 participants yielded comparable results (PCC = 0.837) as 15 models trained individually for these participants (PCC = 0.831). Furthermore, the multi-subject models achieved high performance on unseen participants, with an average PCC = 0.765 in leave-one-out cross-validation.Significance.The proposed SwinTW decoder enables future speech decoding approaches to utilize any electrode placement that is clinically optimal or feasible for a particular participant, including using only depth electrodes, which are more routinely implanted in chronic neurosurgical procedures. The success of the single multi-subject model when tested on participants within the training cohort demonstrates that the model architecture is capable of exploiting data from multiple participants with diverse electrode placements. The architecture's flexibility in training with both single-subject and multi-subject data, as well as grid and non-grid electrodes, ensures its broad applicability. Importantly, the generalizability of the multi-subject models in our study population suggests that a model trained using paired acoustic and neural data from multiple patients can potentially be applied to new patients with speech disability where acoustic-neural training data is not feasible.

Multi-spacecraft observations of the decay phase of solar energetic particle events

The parameters of solar energetic particle (SEP) event profiles such as the onset time and peak time have been researched extensively to obtain information on the acceleration and transport of SEPs. The corotation of particle-filled magnetic flux tubes with the Sun is generally thought to play a minor role in determining intensity profiles. However recent simulations have suggested that corotation affects the SEP decay phases and depends on the location of the observer with respect to the active region associated with the event. We aim to determine whether signatures of corotation are present in observations of the decay phases of SEP events, and we study the dependence of the parameters of the decay phase on the properties of the flares and coronal mass ejections associated with the events. We analysed multi-spacecraft observations of SEP intensity profiles from 11 events between 2020 and 2022 using data from Solar Orbiter, PSP, STEREO-A, and SOHO. We determined the decay-time constant, τ, in three energy channels; electrons ∼1 MeV, protons ∼25 MeV, and protons ∼60 MeV. We studied the dependence of τ on the longitudinal separation, Δ ϕ, between the source of the active region and the spacecraft magnetic footpoint on the Sun. Individual events show a tendency for the decay-time constant to decrease with increasing Δ ϕ. This agrees with test particle simulations. The magnitude of the event as measured through the intensity of the associated flare and SEP peak flux affects the measured τ values and likely is the cause of the observed large inter-event variability together with the varying solar wind and the conditions in the interplanetary magnetic field. We conclude that corotation affects decay phase of an SEP event and should be included in future simulations and interpretations of these events.

Seeing Into the Future: Adults' Accuracy Predicting the Vocabulary of Early Symbolic Communicators Who Use Augmentative and Alternative Communication.

Vocabulary access is important for individuals who use augmentative and alternative communication (AAC), especially for children in the early stages of language learning. This study sought to understand how accurate speech-language pathologists (SLPs), teachers, and parents are in predicting the vocabulary needed by early symbolic communicators who use AAC in three contexts. Ten groups, each with a child who used AAC as their primary mode of communication and who was classified as an early symbolic communicator and their parent, teacher, and SLP, participated. The parents, teachers, and SLPs predicted a vocabulary list of words children who use AAC needed to participate in a dinner, a math lesson, and a speech session using the blank page method and categorical inventories technique. Children were then recorded in 15-min videos participating in the three contexts. Words were recorded and compared to the words predicted. There was large variability in the accuracy of percentage of words the children used that were predicted by the adults out of all the words the children used. The adults were significantly more accurate predicting the vocabulary for the math lesson than the dinner. Parents, teachers, and SLPs predicted much of the vocabulary of early symbolic communicators who use AAC. Implications for early vocabulary selection and alternatives to predicting vocabulary are discussed.

Sequential use of low-load-blood-flow-restricted vs. high-load resistance training on neuromuscular activation, hypertrophy and neuromuscular performance

Introduction Low-load Blood Flow Restriction training (BFRT) is a viable alternative to high-load resistance training (HLT), especially for clinical populations, due to its lower mechanical tension (Centner et al., 2019). Despite using lower loads, BFRT achieves comparable or slightly lower gains in muscle hypertrophy and strength than HLT. However, neural adaptations after low-load BFRT remain poorly understood and are hypothesized to be less pronounced (Centner &amp; Lauber, 2020). Thus, this study aimed to compare the effects of BFRT and HLT, as well as the sequential application of HLT following BFRT, to address potential gaps in neuromuscular adaptation (Duchateau et al., 2021). Methods In this 10-week randomized controlled trial, 37 healthy male and female adults (35-60 years) completed progressive resistance training for knee extensors either 8 weeks with low-load BFRT followed by 2 weeks of HLT, or exclusively HLT. Measurements at baseline including familiarization (PRE1 and PRE2), 8 weeks (MID) and 10 weeks (POST) included maximal voluntary contraction of knee extensors (MVC), leg press strength (LP), voluntary activation (VA, via electrical muscle stimulation) and vastus lateralis muscle volume (V_VL, via ultrasound at 30-70% femur length). Linear mixed models were used to analyze group differences over time, with Cohen’s d effect sizes. Here, we report the preliminary data of 20 participants. Results Reliability between PRE1 and PRE2 was excellent for MVC and V_VL (ICC&gt;0.98) and good for LP (ICC=0.88). From PRE2 to POST, MVC showed a moderate overall increase (+14.7%, d=0.49), while from MID to POST the BFRT group benefited slightly more (d=-0.14). LP increased similarly in both groups at MID (+5.9), but at POST, the HLT group demonstrated a greater increase compared to the BFRT group (+14.8%, d=0.32). No meaningful differences in VA changes were observed between groups or across timepoint, however, the interaction at POST favored more change in BFRT compared to HLT (d=-0.3). Both groups showed comparable increases in V_VL, with negligible differences between groups (+3.4%, d=0.05). Discussion/Conclusion The results of the analyzed sub-sample imply that BFRT and HLT lead to similar changes in maximal force, neural adaptation, and muscle size, however, a large variability was found. The greater increase in VA and MVC in the BFRT group at POST suggests that sequential HLT training after BFRT may enhance performance more than HLT alone (Duchateau et al., 2021). The analysis of the remaining participants may help clarify these effects and enlighten, how mechanical tension and metabolic stress contribute to neural adaptations.