44 research outputs found
Exposing flaws of generative model evaluation metrics and their unfair treatment of diffusion models
We systematically study a wide variety of generative models spanning
semantically-diverse image datasets to understand and improve the feature
extractors and metrics used to evaluate them. Using best practices in
psychophysics, we measure human perception of image realism for generated
samples by conducting the largest experiment evaluating generative models to
date, and find that no existing metric strongly correlates with human
evaluations. Comparing to 17 modern metrics for evaluating the overall
performance, fidelity, diversity, rarity, and memorization of generative
models, we find that the state-of-the-art perceptual realism of diffusion
models as judged by humans is not reflected in commonly reported metrics such
as FID. This discrepancy is not explained by diversity in generated samples,
though one cause is over-reliance on Inception-V3. We address these flaws
through a study of alternative self-supervised feature extractors, find that
the semantic information encoded by individual networks strongly depends on
their training procedure, and show that DINOv2-ViT-L/14 allows for much richer
evaluation of generative models. Next, we investigate data memorization, and
find that generative models do memorize training examples on simple, smaller
datasets like CIFAR10, but not necessarily on more complex datasets like
ImageNet. However, our experiments show that current metrics do not properly
detect memorization: none in the literature is able to separate memorization
from other phenomena such as underfitting or mode shrinkage. To facilitate
further development of generative models and their evaluation we release all
generated image datasets, human evaluation data, and a modular library to
compute 17 common metrics for 9 different encoders at
https://github.com/layer6ai-labs/dgm-eval.Comment: NeurIPS 2023. 53 pages, 29 figures, 12 tables. Code at
https://github.com/layer6ai-labs/dgm-eval, reviews at
https://openreview.net/forum?id=08zf7kTOo
Performance of serum-supplemented and serum-free media in IFNγ Elispot Assays for human T cells
The choice of serum for supplementation of media for T cell assays and in particular, Elispot has been a major challenge for assay performance, standardization, optimization, and reproducibility. The Assay Working Group of the Cancer Vaccine Consortium (CVC-CRI) has recently identified the choice of serum to be the leading cause for variability and suboptimal performance in large international Elispot proficiency panels. Therefore, a serum task force was initiated to compare the performance of commercially available serum-free media to laboratories’ own medium/serum combinations. The objective of this project was to investigate whether a serum-free medium exists that performs as well as lab-own serum/media combinations with regard to antigen-specific responses and background reactivity in Elispot. In this way, a straightforward solution could be provided to address the serum challenge. Eleven laboratories tested peripheral blood mononuclear cells (PBMC) from four donors for their reactivity against two peptide pools, following their own Standard Operating Procedure (SOP). Each laboratory performed five simultaneous experiments with the same SOP, the only difference between the experiments was the medium used. The five media were lab-own serum-supplemented medium, AIM-V, CTL, Optmizer, and X-Vivo. The serum task force results demonstrate compellingly that serum-free media perform as well as qualified medium/serum combinations, independent of the applied SOP. Recovery and viability of cells are largely unaffected by serum-free conditions even after overnight resting. Furthermore, one serum-free medium was identified that appears to enhance antigen-specific IFNγ-secretion
The correlation between exaggerated fluid in lumbar facet joints and degenerative spondylolisthesis: prospective study of 52 patients
Magnetic resonance imaging (MRI) is often used to evaluate low back pain; however, MRI in the supine position does not always reveal degenerative spondylolisthesis. The existence of a linear correlation between increased fluid in the facet joints seen on the supine axial T2 MRI of the lumbosacral spine and lumbar instability seen on standing lateral flexion-extension lumbosacral radiographs has recently been reported. The objective of this prospective study was to determine the incidence of increased fluid in the lumbar facet joints seen on the supine axial T2 MRI, and to evaluate the correlation of this finding with radiographic evidence of lumbar instability
Biventricular responses to exercise and their relation to cardiorespiratory fitness in pediatric pulmonary hypertension.
This is the final version. Available from American Physiological Society via the DOI in this record. Data availability.
Deidentified data used in this analysis cannot be made publicly available as it might contain sensitive information but can be shared upon reasonable request to the corresponding author, and data sharing agreements compliant with local and international data privacy laws are implemented.Despite exercise intolerance being predictive of outcomes in pulmonary arterial hypertension (PAH), its underlying cardiac mechanisms are not well described. The aim of the study was to explore the biventricular response to exercise and its associations with cardiorespiratory fitness in children with PAH. Participants underwent incremental cardiopulmonary exercise testing and simultaneous exercise echocardiography on a recumbent cycle ergometer. Linear mixed models were used to assess cardiac function variance and associations between cardiac and metabolic parameters during exercise. Eleven participants were included with a mean age of 13.4 ± 2.9 yr old. Right ventricle (RV) systolic pressure (RVsp) increased from a mean of 59 ± 25 mmHg at rest to 130 ± 40 mmHg at peak exercise (P < 0.001), whereas RV fractional area change (RV-FAC) and RV-free wall longitudinal strain (RVFW-Sl) worsened (35.2 vs. 27%, P = 0.09 and -16.6 vs. -14.6%, P = 0.1, respectively). At low- and moderate-intensity exercise, RVsp was positively associated with stroke volume and O2 pulse (P < 0.1). At high-intensity exercise, RV-FAC, RVFW-Sl, and left ventricular longitudinal strain were positively associated with oxygen uptake and O2 pulse (P < 0.1), whereas stroke volume decreased toward peak (P = 0.04). In children with PAH, the increase of pulmonary pressure alone does not limit peak exercise, but rather the concomitant reduced RV functional reserve, resulting in RV to pulmonary artery (RV-PA) uncoupling, worsening of interventricular interaction and LV dysfunction. A better mechanistic understanding of PAH exercise physiopathology can inform stress testing and cardiac rehabilitation in this population. New and Noteworthy - In children with pulmonary arterial hypertension, there is a marked increase in pulmonary artery pressure during physical activity, but this is not the underlying mechanism that limits exercise. Instead, right ventricle-to-pulmonary artery uncoupling occurs at the transition from moderate to high-intensity exercise and correlates with lower peak oxygen uptake. This highlights the more complex underlying pathological responses and the need for multiparametric assessment of cardiac function reserve in these patients when feasible.Labatt Family Heart CenterUK Research and Innovation (UKRI)Medical Research Council (MRC
A web-based intervention to promote physical activity in adolescents and young adults with cystic fibrosis: protocol for a randomized controlled trial
BACKGROUND
Regular participation in physical activity by people with cystic fibrosis (CF) promotes positive clinical and health outcomes including reduced rate of decline in lung function, fewer hospitalizations and greater wellbeing. However adherence to exercise and activity programs is low, in part due to the substantial daily therapy burden for young people with CF. Strict infection control requirements limit the role of group exercise programs that are commonly used in other clinical groups. Investigation of methods to promote physical activity in this group has been limited. The Active Online Physical Activity in Cystic fibrosis Trial (ActionPACT) is an assessor-blinded, multi-centre, randomized controlled trial designed to compare the efficacy of a novel web-based program (ActivOnline) compared to usual care in promoting physical activity participation in adolescents and young adults with CF.
METHODS
Adolescents and young adults with CF will be recruited on discharge from hospital for a respiratory exacerbation. Participants randomized to the intervention group will have access to a web-based physical activity platform for the 12-week intervention period. ActivOnline allows users to track their physical activity, set goals, and self-monitor progress. All participants in both groups will be provided with standardised information regarding general physical activity recommendations for adolescents and young adults.
Outcomes will be assessed by a blinded assessor at baseline, after completion of the intervention, and at 3-months followup. Healthcare utilization will be assessed at 12 months from intervention completion. The primary outcome is change in moderate-to-vigorous physical activity participation measured objectively by accelerometry. Secondary outcomes include aerobic fitness, health-related quality of life, anxiety and depression and sleep quality.
DISCUSSION
This trial will establish whether a web-based application can improve physical activity participation more effectively than usual care in the period following hospitalization for a respiratory exacerbation. The web-based application under investigation can be made readily and widely available to all individuals with CF, to support physical activity and exercise participation at a time and location of the user’s choosing, regardless of microbiological status.
TRIAL REGISTRATION
Clinical trial registered on July 13, 2017 with the Australian and New Zealand Clinical Trials Register at (ACTRN12617001009303)
The Exeter Activity Unlimited statement on physical activity and exercise for cystic fibrosis: methodology and results of an international, multidisciplinary, evidence-driven expert consensus
This is the final version. Available on open access from SAGE Publications via the DOI in this recordData availability statement: All results are presented within the manuscript and supplementary files.BACKGROUND: The roles of physical activity (PA) and exercise within the management of cystic fibrosis (CF) are recognised by their inclusion in numerous standards of care and treatment guidelines. However, information is brief, and both PA and exercise as multi-faceted behaviours require extensive stakeholder input when developing and promoting such guidelines. METHOD: On 30th June and 1st July 2021, 39 stakeholders from 11 countries, including researchers, healthcare professionals and patients participated in a virtual conference to agree an evidence-based and informed expert consensus about PA and exercise for people with CF. This consensus presents the agreement across six themes: (i) patient and system centred outcomes, (ii) health benefits, iii) measurement, (iv) prescription, (v) clinical considerations, and (vi) future directions. The consensus was achieved by a stepwise process, involving: (i) written evidence-based synopses; (ii) peer critique of synopses; (iii) oral presentation to consensus group and peer challenge of revised synopses; and (iv) anonymous voting on final proposed synopses for adoption to the consensus statement. RESULTS: The final consensus document includes 24 statements which surpassed the consensus threshold (>80% agreement) out of 30 proposed statements. CONCLUSION: This consensus can be used to support health promotion by relevant stakeholders for people with CF.Cystic Fibrosis Trus
Fitzgerald, Hemingway, and Morrill Cody: Two Degrees of Separation, or the One That Got Away
Aims to bring the life and writing of Morrill Cody, journalist in 1920s Paris and friend to Fitzgerald and Hemingway, back into the critical spotlight. Celebrates Cody\u27s literary contributions, including his memoir The Women of Montparnasse (1984), which features a chapter on Hemingway\u27s first wife, Hadley, describing her as the best-liked woman in Montparnasse. Highlights a number of his other works of interest to students and scholars of the modernist era such as This Must Be the Place: Memoirs of Montparnasse by Jimmie \u27The Barman\u27 Charters, As Told to Morrill Cody (1934), reprints notes sent by Hemingway to Cody regarding his writing of the book\u27s introduction, and recounts remarks Cody made about Hemingway at a 1973 Paris conference
Diritto penale della miseria, miseria del diritto penale
Il volume raccoglie contributi interdisciplinari sul tema del rapporto tra sistema penale e miseri