Menthyl acetate powered self-propelled Janus sponge Marangoni motors with self-maintaining surface tension gradients and active mixing.

HYPOTHESIS: Small scale Marangoni motors, which self-generate motion by inducing surface tension gradients on water interfaces through release of surface-active "fuels", have recently been proposed as self-powered mixing devices for low volume fluids. Such devices however, often show self-limiting lifespans due to the rapid saturation of surface-active agents. A potential solution to this is the use volatile surface-active agents which do not persist in their environment. Here we investigate menthyl acetate (MA) as a safe, inexpensive and non-persistent fuel for Marangoni motors. EXPERIMENTS: MA was loaded asymmetrically into millimeter scale silicone sponges. Menthyl acetate reacts slowly with water to produce the volatile surface-active menthol, which induces surface tension gradients across the sponge to drive motion by the Marangoni effect. Videos were taken and trajectories determined by custom software. Mixing was assessed by the ability of Marangoni motors to homogenize milliliter scale aqueous solutions containing colloidal sediments. FINDINGS: Marangoni motors, loaded with asymmetric "Janus" distributions of menthyl acetate show velocities and rotational speeds up to 30 mm s-1 and 500 RPM respectively, with their functional lifetimes scaling linearly with fuel volume. We show these devices are capable of enhanced mixing of solutions at orders of magnitude greater rates than diffusion alone.

Multiband accelerated 2D EPI for multi-echo brain QSM at 3 T.

PURPOSE: Data for QSM are typically acquired using multi-echo 3D gradient echo (GRE), but EPI can be used to accelerate QSM and provide shorter acquisition times. So far, EPI-QSM has been limited to single-echo acquisitions, which, for 3D GRE, are known to be less accurate than multi-echo sequences. Therefore, we compared single-echo and multi-echo EPI-QSM reconstructions across a range of parallel imaging and multiband acceleration factors. METHODS: Using 2D single-shot EPI in the brain, we compared QSM from single-echo and multi-echo acquisitions across combined parallel-imaging and multiband acceleration factors ranging from 2 to 16, with volume pulse TRs from 21.7 to 3.2 s, respectively. For single-echo versus multi-echo reconstructions, we investigated the effect of acceleration factors on regional susceptibility values, temporal noise, and image quality. We introduce a novel masking method based on thresholding the magnitude of the local field gradients to improve brain masking in challenging regions. RESULTS: At 1.6-mm isotropic resolution, high-quality QSM was achieved using multi-echo 2D EPI with a combined acceleration factor of 16 and a TR of 3.2 s, which enables functional applications. With these high acceleration factors, single-echo reconstructions are inaccurate and artefacted, rendering them unusable. Multi-echo acquisitions greatly improve QSM quality, particularly at higher acceleration factors, provide more consistent regional susceptibility values across acceleration factors, and decrease temporal noise compared with single-echo QSM reconstructions. CONCLUSION: Multi-echo acquisition is more robust for EPI-QSM across parallel imaging and multiband acceleration factors than single-echo acquisition. Multi-echo EPI can be used for highly accelerated acquisition while preserving QSM accuracy and quality relative to gold-standard 3D-GRE QSM.

Automated assessment of task-based performance of digital mammography and tomosynthesis systems using an anthropomorphic breast phantom and deep learning-based scoring.

Purpose: Conventional metrics used for assessing digital mammography (DM) and digital breast tomosynthesis (DBT) image quality, including noise, spatial resolution, and detective quantum efficiency, do not necessarily predict how well the system will perform in a clinical task. A number of existing phantom-based methods have their own limitations, such as unrealistic uniform backgrounds, subjective scoring using humans, and regular signal patterns unrepresentative of common clinical findings. We attempted to address this problem with a realistic breast phantom with random hydroxyapatite microcalcifications and semi-automated deep learning-based image scoring. Our goal was to develop a methodology for objective task-based assessment of image quality for tomosynthesis and DM systems, which includes an anthropomorphic phantom, a detection task (microcalcification clusters), and automated performance evaluation using a convolutional neural network. Approach: Experimental 2D and pseudo-3D mammograms of an anthropomorphic inkjet-printed breast phantom with inserted microcalcification clusters were collected on clinical mammography systems to train a signal-present/signal-absent image classifier based on Resnet-18 architecture. In a separate validation study using simulations, this Resnet-18 classifier was shown to approach the performance of an ideal observer. Microcalcification detection performance was evaluated as a function of four dose levels using receiver operating characteristic (ROC) analysis [i.e., area under the ROC curve (AUC)]. To demonstrate the use of this evaluation approach for assessing different technologies, the method was applied to two different mammography systems, as well as to mammograms with re-binned pixels emulating a lower-resolution X-ray detector. Results: Microcalcification detectability, as assessed by the deep learning classifier, was observed to vary with the exposure incident on the breast phantom for both DM and tomosynthesis. At full dose, experimental AUC was 0.96 (for DM) and 0.95 (for DBT), whereas at half dose, it dropped to 0.85 and 0.71, respectively. AUC performance on DM was significantly decreased with an effective larger pixel size obtained with re-binning. The task-based assessment approach also showed the superiority of a newer mammography system compared with an older system. Conclusions: An objective task-based methodology for assessing the image quality of mammography and tomosynthesis systems is proposed. Possible uses for this tool could be quality control, acceptance, and constancy testing, assessing the safety and effectiveness of new technology for regulatory submissions, and system optimization. The results from this study showed that the proposed evaluation method using a deep learning model observer can track differences in microcalcification signal detectability with varied exposure conditions.

Microglia are essential for tissue contraction in wound closure after brain injury in zebrafish larvae.

Wound closure after brain injury is crucial for tissue restoration but remains poorly understood at the tissue level. We investigated this process using in vivo observations of larval zebrafish brain injury. Our findings show that wound closure occurs within the first 24 h through global tissue contraction, as evidenced by live-imaging and drug inhibition studies. Microglia accumulate at the wound site before closure, and computational models suggest that their physical traction could drive this process. Depleting microglia genetically or pharmacologically impairs tissue repair. At the cellular level, live imaging reveals centripetal deformation of astrocytic processes contacted by migrating microglia. Laser severing of these contacts causes rapid retraction of microglial processes and slower retraction of astrocytic processes, indicating tension. Disrupting the lcp1 gene, which encodes the F-actin-stabilising protein L-plastin, in microglia results in failed wound closure. These findings support a mechanical role of microglia in wound contraction and suggest that targeting microglial mechanics could offer new strategies for treating traumatic brain injury.

FunMaps: a method for parcellating functional brain networks using resting-state functional MRI data.

Parcellations of resting-state functional magnetic resonance imaging (rs-fMRI) data are widely used to create topographical maps of functional networks in the human brain. While such network maps are highly useful for studying brain organization and function, they usually require large sample sizes to make them, thus creating practical limitations for researchers that would like to carry out parcellations on data collected in their labs. Furthermore, it can be difficult to quantitatively evaluate the results of a parcellation since networks are usually identified using a clustering algorithm, like principal components analysis, on the results of a single group-averaged connectivity map. To address these challenges, we developed the FunMaps method: a parcellation routine that intrinsically incorporates stability and replicability of the parcellation by keeping only network distinctions that agree across halves of the data over multiple random iterations. Here, we demonstrate the efficacy and flexibility of FunMaps, while describing step-by-step instructions for running the program. The FunMaps method is publicly available on GitHub (https://github.com/persichetti-lab/FunMaps). It includes source code for running the parcellation and auxiliary code for preparing data, evaluating the parcellation, and displaying the results.

Concepts of Pain Management Following Nerve Injuries: Multidisciplinary Approach.

Purpose: A systematic review to identify treatment approaches for the management of pain following peripheral nerve injury. Methods: A published literature search was performed for the concepts of peripheral nerve injury and pain management with related synonyms. The strategies were created using a combination of controlled vocabulary terms and keywords and were executed in Embase.com, Ovid-Medline All, and Scopus from database inception. Database searches were completed on August 22, 2023. Results: The initial search resulted in a total of 1,793 citations. In total, 724 duplicates were removed, leaving 1,069 unique citations remaining for analysis. This review excluded all papers that were not specific to pain following peripheral nerve injury. Case and cohort studies (n < 5) were also excluded. Thirty-two articles on pain management strategies after peripheral nerve injury remained, with years of publication ranging from 1981 to 2023. An additional four articles were identified by manual search. Of the 36 articles reviewed, 15 articles reported on the approach to the treatment of pain after a peripheral nerve injury, and the other 22 articles consisted of cohort and case series studies. Conclusions: There is a lack of literature describing efficacy of various treatment strategies for pain following peripheral nerve injuries. Few studies provide clear, stepwise clinical guidance for practicing physicians and other health care providers on the treatment of these complicated patients.

Outcomes in infective endocarditis among adults with CHD: a comparative national study.

BACKGROUND: Given increased survival for adults with CHD, we aim to determine outcome differences of infective endocarditis compared to patients with structurally normal hearts in the general population. METHODS: We conducted a retrospective cross-sectional study identifying infective endocarditis hospitalisations in patients 18 years and older from the National Inpatient Sample database between 2001 and 2016 using International Classification of Disease diagnosis and procedure codes. Weighting was used to create national annual estimates indexed to the United States population, and multivariable logistic regression analysis determined variable associations. Outcome variables were mortality and surgery. The primary predictor variable was the presence or absence of CHD. RESULTS: We identified 1,096,858 estimated infective endocarditis hospitalisations, of which 17,729 (1.6%) were adults with CHD. A 125% increase in infective endocarditis hospitalisations occurred for adult CHD patients during the studied time period (p < 0.001). Adults with CHD were significantly less likely to experience mortality (5.4% vs. 9.5%, OR 0.54, CI 0.47-0.63, p < 0.001) and more likely to undergo in-hospital surgery (31.6% vs. 6.7%, OR 6.49, CI 6.03-6.98, p < 0.001) compared to the general population. CHD severity was not associated with increased mortality (p = 0.53). Microbiologic aetiology of infective endocarditis varied between groups (p < 0.001) with Streptococcus identified more commonly in adults with CHD compared to patients with structurally normal hearts (36.2% vs. 14.4%). CONCLUSIONS: Adults with CHD hospitalised for infective endocarditis are less likely to experience mortality and more likely to undergo surgery than the general population.

Associations of takeaway outlets with takeaway food consumption and adiposity: longitudinal analysis of the Fenland cohort.

OBJECTIVE: This study builds on prior findings that link increased availability of takeaway food outlets in home, workplace, and commuting environments to greater takeaway consumption and adiposity. Using longitudinal data, we examine associations of takeaway availability at baseline with changes in consumption and adiposity between baseline and follow-up. METHODS: We analyzed data from the Fenland Study, with baseline data from 2005 to 2015 and follow-up from 2015 to 2020. Takeaway outlet availability within 1 mile of participants' home and workplace addresses, based on 2011 local authority data, was assessed. Outcomes included takeaway food consumption (from a food frequency questionnaire) and body fat percentage (measured via dual-energy x-ray absorptiometry) at follow-up. RESULTS: Among 7581 participants (mean [SD] age, 49.3 [7.4] years) with a mean follow-up of 6.7 years, no positive association was found between takeaway outlet availability at baseline and changes in consumption or body fat percentage. However, among the 12 associations tested, the highest combined home-workplace availability of takeaway outlets, compared with none, was associated with a 0.68 decrease in body fat percentage (95% CI: 0.24-1.12). CONCLUSIONS: Although takeaway outlet availability was linked to greater consumption and adiposity at baseline, it did not predict changes over time, underscoring the complexity of dietary behaviors and their relationship with the neighborhood food environment.

Analysis of Histologic, Immunohistochemical and Genomic Features of Large B Cell Lymphoma Tumors May Predict Response to Polatuzumab Vedotin Based Therapy in Patients With Relapsed/Refractory Disease.

BACKGROUND: Large B cell lymphoma (LBCL) is the most common form of lymphoma. Polatuzumab vedotin (polatuzumab) is an effective therapy for patients diagnosed with LBCL; however, only limited information regarding pathologic features detected by clinical laboratory assays is available to determine which patients are most likely to benefit from polatuzumab based therapies. PATIENTS AND METHODS: We collected data from real world patients with relapsed or refractory LBCL whose tumors underwent next generation sequencing and were treated with polatuzumab based therapy at a single large academic cancer center. Tumor and patient characteristics were analyzed to look for factors that predict response to polatuzumab based therapies. RESULTS: We identified high grade B cell lymphoma (HGBL) -NOS or MYC/BCL2 histology and presence of MYC rearrangement as factors that predict inferior response to polatuzumab based therapy. Patients with germinal center B cell of origin (GCB COO) LBCL without these factors had a high response rate (73%) to polatuzumab based therapy. CONCLUSION: In a single center real world retrospective analysis of R/R LBCL patients with available genomic data, polatuzumab based therapy may be less effective in patients with HGBL-NOS or MYC/BCL2 histology and MYC rearrangements, but not in patients with GCB COO LBCL without these features. Routine performance of more comprehensive pathologic analysis of tumors may inform the use of polatuzumab based therapy in patients with LBCL.

Pathways between grief, depression, hopelessness, reasons for living, and suicidal ideation in bereaved individuals.

BACKGROUND: Associations between comorbid depression and grief with suicidal ideation (SI) have been inconsistent. To identify at-risk individuals, it is important to determine the role of symptom severity by examining both continuous and clinical-threshold grief and depression, in addition to other factors (i.e., hopelessness, reasons for living-RFL) associated with SI. METHODS: Participants (n = 216) bereaved by combat, accident, or suicide completed an online survey. Associations between depression, grief, SI, RFL, and hopelessness were examined by multivariable logistic regressions and structural equation modeling (SEM). RESULTS: Across the sample, hopelessness and RFL were associated with SI while continuous measures of grief and depression were not. In contrast, clinical-threshold grief, clinical-threshold depression, hopelessness, and RFL each were associated with SI. In addition, of the grief characteristics, yearning was the most robust correlate of SI, and Survival/Coping Beliefs (SCB) was the RFL most associated with SI. SEM indicated that direct paths between grief and SI, hopelessness and SI, and RFL and SI were significant, but not between depression and SI. Instead, depression had a strong direct effect on hopelessness, and hopelessness had a direct effect on SI. DISCUSSION: Results are consistent with previously-identified associations between SI and clinical levels of depression and grief. More nuanced findings suggest hopelessness, yearning, and SCB as additional targets for reducing risk for SI in bereaved individuals regardless of whether they meet clinical thresholds for grief or depression.

Interplay of Age and Risk Factor Control Upon Coronary Atheroma Progression.

BACKGROUND & AIM: The extent and composition of coronary plaque, and its progression differ with patients' age. The interplay of patient's age with respect to risk factor control, upon atheroma progression has not been evaluated. We tested the hypothesis that risk factor control modulates the association between age and coronary atheroma progression. METHOD: We performed a posthoc pooled analysis of data from 10 prospective, randomised trials involving serial coronary intravascular ultrasonography (IVUS) (n=5,823). The percent atheroma volume (PAV) was calculated as the proportion of the entire vessel wall occupied by atherosclerotic plaque. RESULTS: Mean overall age was 58±9 years (28% women). In a fully adjusted multivariable analysis (following adjustment of sex, body mass index, systolic blood pressure [SBP], smoking, high-density lipoprotein and low-density lipoprotein [LDL]-cholesterol, triglyceride levels, peripheral vascular disease, diabetes mellitus, trial, region, and baseline PAV), an increase in age by one standard deviation was linked with PAV progression (ß-estimate 0.097; 95% confidence interval 0.048-0.15; p<0.001). In patients with good risk factor control (LDL-cholesterol <1.8 mmol/L and SBP <130 mmHg), increasing age remained associated with PAV progression (0.123; 0.014-0.23; p=0.027). Lower effect sizes for the association of age with PAV progression were observed for patients with partial control of LDL-cholesterol and SBP and were not significantly associated with PAV progression when both LDL-cholesterol and SBP were not controlled (0.099; 0.032-0.167; p=0.004 and 0.042; -0.056 to 0.14; p=0.40, respectively). CONCLUSIONS: Patient age is directly associated with coronary atheroma progression independently of traditional cardiovascular risk factors. In the setting of poor risk factor control, the influence of age on coronary artery disease progression is attenuated.

Incidence and Risk Factors for Lumbar Sympathetic Chain Injury After Oblique Lumbar Interbody Fusion.

OBJECTIVE: Oblique lumbar interbody fusion (OLIF), performed using a retroperitoneal approach, can lead to complications related to the approach, such as lumbar sympathetic chain injury (LSCI). Although LSCI is a common complication of OLIF, its reported incidence varies across studies due to an absence of specific diagnostic criteria. Moreover, research on the risk factors of postoperative sympathetic chain injuries after OLIF remains limited. Therefore, this study aimed to describe the incidence, and identify independent risk factors for LSCI, in patients with degenerative lumbar spinal diseases who underwent OLIF. METHODS: Between October 2020 and August 2023, a retrospective review was conducted at our institute on 200 patients who underwent OLIF at 1 to 4 consecutive spinal levels (L1-5) for degenerative spinal diseases including spinal stenosis, spondylolisthesis, degenerative scoliosis. We excluded those with infections, trauma, tumors, and lower extremity edema/warmth due to other causes. The patients were categorized into 2 groups: those with and without LSCI symptoms. Demographic data, operative data, and pre- and postoperative parameters were evaluated for their association with LSCI using a univariate logistic regression model. Variables with a p-value <0.1 in the univariate analysis were included in a multivariate model to identify the independent risk factors. RESULTS: Thirty-five of 200 patients (17.5%) developed LSCI symptoms after OLIF. Multivariate logistic regression analysis indicated that prolonged retraction time, particularly exceeding 31.5 miniutes, remained an independent risk factor (adjusted odds ratio, 12.59; p<0.001). CONCLUSION: This study demonstrated that prolonged retraction time was an independent risk factor for LSCI following OLIF, particularly when it exceeded 31.5 minutes. Protecting the lumbar sympathetic chain during surgery and minimizing retraction time are crucial to avoiding LSCI following OLIF.

Risk Factors of Unsatisfactory Outcomes Requiring Additional Intervention Following Oblique Lateral Interbody Fusion.

OBJECTIVE: Oblique lateral interbody fusion (OLIF) is a minimally invasive procedure for stabilizing the spine and indirectly decompressing the neural elements. There is sparse data on unsatisfactory outcomes that require additional interventions (surgery or intervention) after OLIF. This study aimed to identify the causes, and risk factors of these reintervention. METHODS: This was a single-center retrospective study of the patients who underwent the OLIF procedure from June 2016 to March 2023. Several clinical and radiographic parameters were studied. We also analyzed associations between several potential risk factors and the reintervention following OLIF. RESULTS: A total of 231 patients were included. Over an average of 2.5 years of follow-up, 28 patients (12.1%) required a reintervention. Adjacent segment disease (ASD) was the most common cause of reintervention. The risk factors associated with reintervention were previous surgery (adjusted odds ratio [aOR], 4.44; 95% confidence interval [CI], 1.21-16.33; p=0.02) and high preoperative Oswestry Disability Index (ODI) scores (aOR, 1.04; 95% CI, 1.00-1.08; p=0.03). Although increasing the duration of follow-up was not statistically significant, the 95% CI was consistent with an increased risk of reintervention with longer follow-up (OR, 1.18; 95% CI, 0.94-1.50). CONCLUSION: This study showed that patients with prior lumbar surgery and high preoperative ODI scores were more likely to require additional intervention after the OLIF procedure. In addition, an increasing duration of follow-up was associated with an increased risk of reintervention. The most common reason for reintervention was ASD after OLIF.

A Novel Deep Ensemble Method for Selective Classification of Electrocardiograms.

OBJECTIVE: Telehealth paradigms are essential for remotely managing patients with chronic conditions. To assist clinicians in handling the large volumes of data collected through these systems, clinical decision support systems (CDSSs) have been developed. However, the effectiveness of CDSSs depends on the quality of remotely recorded physiological data and the reliability of the algorithms used for processing this data. This study aims to reliably detect atrial fibrillation (AF) from short-term single-lead (STSL) electrocardiogram (ECG) recordings obtained in unsupervised telehealth environments. METHODS: A novel deep ensemble-based method was developed for detecting AF from STSL ECG recordings. Following this, a postprocessing algorithm was created to assess uncertainty in classified STSL ECGs and to refrain from interpretation when confidence is low. The proposed method was validated through a 5-fold cross-validation on the Cardiology Challenge 2017 (CinC2017) dataset. RESULTS: The deep ensemble method achieved 83.5 ± 1.5% sensitivity, 98.4 ± 0.2% specificity, and an F 1-score of 0.847 ± 0.016in AF detection. Implementing the selective classification algorithm resulted in significant improvements, with sensitivity increasing to 92.8 ± 2.2%, specificity to 99.7 ± 0.0%, and an F 1-score of 0.919 ± 0.016. CONCLUSION: The proposed method demonstrates the feasibility of accurately detecting AF from STSL ECG recordings. The selective classification approach offers a substantial enhancement to automated ECG interpretation algorithms in telehealth solutions. SIGNIFICANCE: These findings highlight the potential for improving the utility of telehealth systems by integrating advanced CDSSs capable of managing uncertainty and ensuring higher accuracy, thereby improving patient outcomes in remote healthcare settings.

Parameter quantification for oxygen transport in the human brain.

BACKGROUND AND OBJECTIVE: Oxygen is carried to the brain by blood flow through generations of vessels across a wide range of length scales. This multi-scale nature of blood flow and oxygen transport poses challenges on investigating the mechanisms underlying both healthy and pathological states through imaging techniques alone. Recently, multi-scale models describing whole brain perfusion and oxygen transport have been developed. Such models rely on effective parameters that represent the microscopic properties. While parameters of the perfusion models have been characterised, those for oxygen transport are still lacking. In this study, we set to quantify the parameters associated with oxygen transport and their uncertainties. METHODS: Effective parameter values of a continuum-based porous multi-scale, multi-compartment oxygen transport model are systematically estimated. In particular, geometric parameters that capture the microvascular topologies are obtained through statistically accurate capillary networks. Maximum consumption rates of oxygen are optimised to uniquely define the oxygen distribution over depth. Simulations are then carried out within a one-dimensional tissue column and a three-dimensional patient-specific brain mesh using the finite element method. RESULTS: Effective values of the geometric parameters, vessel volume fraction and surface area to volume ratio, are found to be 1.42% and 627 [mm2/mm3], respectively. These values compare well with those acquired from human and monkey vascular samples. Simulation results of the one-dimensional tissue column show qualitative agreement with experimental measurements of tissue oxygen partial pressure in rats. Differences between the oxygenation level in the tissue column and the brain mesh are observed, which highlights the importance of anatomical accuracy. Finally, one-at-a-time sensitivity analysis reveals that the oxygen model is not sensitive to most of its parameters; however, perturbations in oxygen solubilities and plasma to whole blood oxygen concentration ratio have a considerable impact on the tissue oxygenation. CONCLUSIONS: The findings of this study demonstrate the validity of using a porous continuum approach to model organ-scale oxygen transport and draw attention to the significance of anatomy and parameters associated with inter-compartment diffusion.

Carbon-13 Hyperpolarization of α-Ketocarboxylates with Parahydrogen in Reversible Exchange.

Signal Amplification by Reversible Exchange (SABRE) is a relatively simple and fast hyperpolarization technique that has been used to hyperpolarize the α-ketocarboxylate pyruvate, a central metabolite and the leading hyperpolarized MRI contrast agent. In this work, we show that SABRE can readily be extended to hyperpolarize 13C nuclei at natural abundance on many other α-ketocarboxylates. Hyperpolarization is observed and optimized on pyruvate (P13C=17%) and 2-oxobutyrate (P13C=25%) with alkyl chains in the R-group, oxaloacetate (P13C=11%) and alpha-ketoglutarate (P13C=13%) with carboxylate moieties in the R group, and phenylpyruvate (P13C=2%) and phenylglyoxylate (P13C=2%) with phenyl rings in the R-group. New catalytically active SABRE binding motifs of the substrates to the hyperpolarization transfer catalyst-particularly for oxaloacetate-are observed. We experimentally explore the connection between temperature and exchange rates for all of these SABRE systems and develop a theoretical kinetic model, which is used to fit the hyperpolarization build-up and decay during SABRE activity.

Warming reduces trophic diversity in high-latitude food webs.

The physical effects of climate warming have been well documented, but the biological responses are far less well known, especially at the ecosystem level and at large (intercontinental) scales. Global warming over the next century is generally predicted to reduce food web complexity, but this is rarely tested empirically due to the dearth of studies isolating the effects of temperature on complex natural food webs. To overcome this obstacle, we used 'natural experiments' across 14 streams in Iceland and Russia, with natural warming of up to 20°C above the coldest stream in each high-latitude region, where anthropogenic warming is predicted to be especially rapid. Using biomass-weighted stable isotope data, we found that community isotopic divergence (a universal, taxon-free measure of trophic diversity) was consistently lower in warmer streams. We also found a clear shift towards greater assimilation of autochthonous carbon, which was driven by increasing dominance of herbivores but without a concomitant increase in algal stocks. Overall, our results support the prediction that higher temperatures will simplify high-latitude freshwater ecosystems and provide the first mechanistic glimpses of how warming alters energy transfer through food webs at intercontinental scales.

Cardiorespiratory Fitness in Childhood Cancer Survivors: A Systematic Review and Meta-Analysis.

AIMS: Cardiovascular disease (CVD) is a leading cause of mortality in childhood cancer survivors (CCS) that may be related to the cardiotoxic effects of radiation or chemotherapy and concomitant reductions in cardiorespiratory fitness. Therefore, we sought to compare cardiorespiratory fitness (peak oxygen uptake, V̇O2peak) between CCS and age-matched non-cancer controls (CON). Secondary outcomes included hemodynamics and resting cardiac function. METHODS: Embase, Scopus, MEDLINE, CINAHL and SPORTDiscus databases were searched from inception to June 2023 for eligible studies. Cross-sectional studies with V̇O2peak measured in CCS and CON were included. Differences in outcomes and pooled estimates for each outcome were estimated from a fixed effects meta-analysis and between group differences were reported as a weighted mean difference (WMD). RESULTS: Of 2026 studies identified, 18 reported V̇O2peak (CCS: n=786, 44% female, mean age: 16-years, time post-therapy: 5.8 years; CON: n=1379, 50% female, mean age: 16-years). V̇O2peak was lower in CCS (WMD: -7.08mL/kg/min, 95% CI: -7.75 to -6.42, I2: 79%, n=2,165) with no difference for peak exercise heart rate (WMD: -1.4bpm, 95% CI: -3.0 to 0.2, I2: 63%, n=741). Resting left-ventricular ejection fraction (WMD: -1.61%, 95% CI: -2.60 to -0.62, I2.: 49%, n=222) and systolic blood pressure were lower (WMD: -3.8mmHg, 95% CI: -5.7 to -1.9, I2: 25%, n=184) while resting heart rate was higher in CCS (WMD: 4.9bpm; 95% CI: 1.8 to 7.9, I2: 55%, n=262). CONCLUSIONS: CCS have a marked reduction in cardiorespiratory fitness (7.1ml/kg/min lower than CON) that may have important prognostic implications for their future risk of CVD and mortality.

Childhood cancer survivors are at increased risk of developing cardiovascular disease, in particular, heart failure. This increased cardiovascular risk is partly due to cardiovascular damage from cancer treatment, but may also be due to reductions in cardiorespiratory fitness that accompany increased sedentary behavior prior to, during, or after cancer treatment. In this review, we assessed the degree of cardiorespiratory fitness impairment and cardiovascular function in childhood cancer survivors relative to their cancer-free peers. Key Findings:  Whilst traditional markers of cardiovascular function appear normal, childhood cancer survivors have a marked reduction in cardiorespiratory fitness that may increase their risk of heart failure and cardiovascular mortality.Measuring cardiorespiratory fitness alongside traditional cardiovascular risk markers may help to identify cancer survivors at increased risk of cardiovascular disease.