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Introduction: Large datasets are required to ensure reliable non-invasive glioma assessment with radiomics-based machine learning methods. This can often only be achieved by pooling images from different centers. Moreover, trained models should perform with high accuracy when applied to data from different centers. In this study, the impact of reconstruction settings and segmentation methods on radiomic features derived from amino acid and TSPO PET images of glioma patients was examined. Additionally, the ability to model and thus reduce feature differences was investigated. Methods: [18F]FET and [18F]GE-180 PET data were acquired from 19 glioma patients. For each acquisition, 10 reconstruction settings and 9 segmentation methods were included to emulate multicentric data. Statistical robustness measures were calculated before and after ComBat harmonization. Differences between features due to setting variations were assessed using Friedman test, coefficient of variation (CV) and inter-rater reliability measures, including intraclass and Spearman’s rank correlation coefficients and Fleiss’ Kappa. Results: According to Friedman analyses, most features (>60%) showed significant differences. Yet, CV and inter-rater reliability measures indicated higher robustness. ComBat resulted in almost complete harmonization (>87%) according to Friedman test and little to no improvement according to CV and inter-rater reliability measures. [18F]GE-180 features were more sensitive to reconstruction settings than [18F]FET features. Conclusions: According to Friedman test, feature distributions could be successfully aligned using ComBat. However, depending on settings, changes in patient ranks were observed for some features and could not be eliminated by harmonization. Thus, for clinical utilization it is recommended to exclude affected features.

This report details calibration method for measurements of 13C/12C and 18O/16O ratios of atmospheric CO2 by the Scripps CO2 program from 1992-2018.  The method depends principally on repeat analysis of CO2 derived from a suite of high-pressure gas cylinders filled with compressed natural air pumped at La Jolla.  The first set of three cylinders were given isotopic assignments in 1994 based on comparisons with material artifacts NBS16, NBS17, and NBS19.  Six cylinders subsequently brought into service were assigned values by comparing directly or indirectly with this first set.  A tenth cylinder with natural CO2 in air was obtained from MPI Jena.  Aliquots of CO2 from these cylinders, which serve as secondary standards, were extracted into heat-sealed glass ampoules (“flame-off tubes”) before introduction into the mass spectrometer.  Some of these ampoules have been stored for many years before analysis, allowing long-term isotopic drift of the cylinders to be quantified.  All secondary standards contain natural levels of N2O.  The method corrects for any detected drift, while also applying corrections for N2O interference, for isobaric interferences (“Craig correction”) and for an inter-lab offset identified in early comparisons with the isotope lab at the University of Groningen.  The Jena cylinder was found to be drifting upwards in δ18O at a rate of +0.10 ‰ per decade.  Five of the other nine cylinders were found to be drifting downwards in δ18O, δ13C, or both, at rates of up to -0.11‰ per decade.  The secondary standards were applied uniformly across a transition to a new mass spectrometer in 2000, thereby establishing continuity across this transition.  Results are presented also for instrumental precision based on replicate analyses of standards.  Drift-corrected analyses of the Jena cylinder establishes offsets of +0.037 ‰ in δ13C and +0.041 ‰ in δ18O between the Scripps and JRAS isotopic scales (Scripps more positive).

Abstract News and social media play an important role in public political discourse. It is not clear what quantifiable relationships public discussions of politics have with official discourse within legislative bodies. In this study we present an analysis of how language used by Members of Parliament (MPs) in the United Kingdom (UK) changes after social media posts and online reactions to those posts. We consider three domains: news articles posted on Facebook in the UK, speeches in the questions-debates in the UK House of Commons, and Tweets by UK MPs. Our method works by quantifying how the words used in one domain become more common in another domain after an event such as a social media post. Our results show that words used in one domain later appear more commonly in other domains. For instance after each article on Facebook, we estimate that on average 4 in 100,000 words in Commons speeches had changed, becoming more similar to the language in the article. We also find that the extent of this language change positively correlates with the number of comments and emotional interactions on Facebook. The observed language change differs between political parties; in particular, changes in word use by Labour MPs are more strongly related to social media content than that of Conservative MPs. We argue that the magnitude of this word flow is quite substantial given the large volume of news articles shared on Facebook. Our method and results quantify how parliamentary attention follows public interest as expressed on Facebook and also indicate how this effect may be stronger for posts which evoke reactions on Facebook associated with laughter or anger.

A decrease in the 13C/12C ratio of atmospheric CO2 has been documented by direct observations since 1978 and from ice core measurements since the industrial revolution. This decrease, known as the 13C-Suess effect, is driven primarily by the input of fossil fuel-derived CO2 but is also sensitive to land and ocean carbon cycling and uptake. Using updated records, we show that no plausible combination of sources and sinks of CO2 from fossil fuel, land, and oceans can explain the observed 13C-Suess effect unless an increase has occurred in the 13C/12C isotopic discrimination of land photosynthesis. A trend toward greater discrimination under higher CO2 levels is broadly consistent with tree ring studies over the past century, with field and chamber experiments, and with geological records of C3 plants at times of altered atmospheric CO2, but increasing discrimination has not previously been included in studies of long-term atmospheric 13C/12C measurements. We further show that the inferred discrimination increase of 0.014 ± 0.007‰ ppm-1 is largely explained by photorespiratory and mesophyll effects. This result implies that, at the global scale, land plants have regulated their stomatal conductance so as to allow the CO2 partial pressure within stomatal cavities and their intrinsic water use efficiency to increase in nearly constant proportion to the rise in atmospheric CO2 concentration.

Abstract To what extent can we predict the structure of online conversation trees? We present a generative model to predict the size and evolution of threaded conversations on social media by combining machine learning algorithms. The model is evaluated using datasets that span two topical domains (cryptocurrency and cyber-security) and two platforms (Reddit and Twitter). We show that it is able to predict both macroscopic features of the final trees and near-future microscopic events with moderate accuracy. However, predicting the macroscopic structure of conversations does not guarantee an accurate reconstruction of their microscopic evolution. Our model’s limited performance in long-range predictions highlights the challenges faced by generative models due to the accumulation of errors.

Purpose: According to the World Health Organization classification for tumors of the central nervous system, mutation status of the isocitrate dehydrogenase (IDH) genes has become a major diagnostic discriminator for gliomas. Therefore, imaging-based prediction of IDH mutation status is of high interest for individual patient management. We compared and evaluated the diagnostic value of radiomics derived from dual positron emission tomography (PET) and magnetic resonance imaging (MRI) data to predict the IDH mutation status non-invasively. Methods: Eighty-seven glioma patients at initial diagnosis who underwent PET targeting the translocator protein (TSPO) using [18F]GE-180, dynamic amino acid PET using [18F]FET, and T1-/T2-weighted MRI scans were examined. In addition to calculating tumor-to-background ratio (TBR) images for all modalities, parametric images quantifying dynamic [18F]FET PET information were generated. Radiomic features were extracted from TBR and parametric images. The area under the receiver operating characteristic curve (AUC) was employed to assess the performance of logistic regression (LR) classifiers. To report robust estimates, nested cross-validation with five folds and 50 repeats was applied. Results: TBRGE-180 features extracted from TSPO-positive volumes had the highest predictive power among TBR images (AUC 0.88, with age as co-factor 0.94). Dynamic [18F]FET PET reached a similarly high performance (0.94, with age 0.96). The highest LR coefficients in multimodal analyses included TBRGE-180 features, parameters from kinetic and early static [18F]FET PET images, age, and the features from TBRT2 images such as the kurtosis (0.97). Conclusion: The findings suggest that incorporating TBRGE-180 features along with kinetic information from dynamic [18F]FET PET, kurtosis from TBRT2, and age can yield very high predictability of IDH mutation status, thus potentially improving early patient management. [ABSTRACT FROM AUTHOR]

BackgroundVideo is a versatile and popular medium for digital health interventions. As mobile device and app technology advances, it is likely that video-based interventions will become increasingly common. Although clinic waiting rooms are complex and busy environments, they offer the opportunity to facilitate engagement with video-based digital interventions as patients wait to see their providers. However, to increase efficiency in public health, leverage the scalability and low cost of implementing digital interventions, and keep up with rapidly advancing technology and user needs, more design and development guidance is needed for video-based tailored interventions. ObjectiveWe provide a tutorial for digital intervention researchers and developers to efficiently design and develop video-based tailored digital health interventions. We describe the challenges and solutions encountered with Positive Health Check (PHC), a hybrid app used to deliver a brief, interactive, individually tailored video-based HIV behavioral counseling intervention. PHC uses video clips and multimedia digital assets to deliver intervention content, including interactive tailored messages and graphics, a repurposed animated video, and patient and provider handouts generated in real time by PHC. MethodsWe chronicle multiple challenges and solutions for the following: (1) using video as a medium to enhance user engagement, (2) navigating the complexity of linking a database of video clips with other digital assets, and (3) identifying the main steps involved in building an app that will seamlessly deliver to users individually tailored messages, graphics, and handouts. ResultsWe leveraged video to enhance user engagement by featuring “video doctors,” full-screen video, storyboards, and streamlined scripts. We developed an approach to link the database of video clips with other digital assets through script coding and flow diagrams of algorithms to deliver a tailored user experience. We identified the steps to app development by using keyframes to design the integration of video and digital assets, using agile development methods to gather iterative feedback from multidisciplinary teams, and creating an intelligent data-driven back-end solution to tailor message delivery to individual users. ConclusionsVideo-based digital health interventions will continue to play an important role in the future of HIV prevention and treatment, as well as other clinical health practices. However, facilitating the adoption of an HIV video intervention in HIV clinical settings is a work in progress. Our experience in designing and developing PHC presented unique challenges due to the extensive use of a large database of videos tailored individually to each user. Although PHC focuses on promoting the health and well-being of persons with HIV, the challenges and solutions presented in this tutorial are transferable to the design and development of video-based digital health interventions focused on other areas of health.

Background: In addition to manual compression, various vascular closure devices (VCD) are available to seal the puncture site following arterial vascular procedures. Purpose: To evaluate the efficacy and safety of the extravascular MYNX CONTROL closure system for achieving primary hemostasis after femoral arterial access following peripheral arterial procedures, compared to the intravascular FemoSeal Aclosure system. Patients and Methods: A retrospective analysis of consecutive patients who underwent endovascular intervention between April and November 2022 was performed. The primary endpoint was the incidence of significant puncture site complication defined as a complication resulting in medical treatment. Secondary endpoints included peri-interventional incidence of hematoma, peri-interventional changes in hemoglobin, incidence of emergency diagnostics and predictors for closure system failure. Results: Five hundred and forty-eight patients were included in this analysis. False aneurysm occurred in 18/273 cases (6.6%) following the use of the MYNX closure system, compared to 6/275 cases after using the FemoSeal closure system (2.2%, p = 0.006). The incidence of post-interventional hematoma was not significantly different (28 (10.3%) in the MYNX group versus 32 (11.6%) in the FemoSeal group, p = 0.358). Peri-interventional hemoglobin drop did not differ between groups (p = 0.449). Emergency diagnostics were not significantly performed more often in the MYNX group (14 (5.1%) versus 8 (2.9%), p = 0.134). A post-interventional duplex sonography showed stenosis at the puncture site in one patient after use of the MYNX system. For the entire cohort, oral anticoagulation was the only predictor for the failure of the closure device (p = 0.036). Conclusions: Device failure was more common after using the extravascular MYNX CONTROL system than after using the intravascular FemoSeal system. However, the need for surgical or interventional therapy due to device failure was low. [ABSTRACT FROM AUTHOR]

Multimedia has the potential of providing bioscience education novel learning environments and pedagogy applications to foster student interest, involve students in the research process, advance critical thinking/problem-solving skills, and develop conceptual understanding of biological topics. "Cancer Cell Biology," an interactive, multimedia, problem-based module, focuses on how mutations in protooncogenes and tumor suppressor genes can lead to uncontrolled cell proliferation by engaging students as research scientists/physicians with the task of diagnosing the molecular basis of tumor growth for a group of patients. The process of constructing the module, which was guided by scientist and student feedback/responses, is described. The completed module and insights gained from its development are presented as a potential "multimedia pedagogy" for the development of other multimedia science learning environments. (Contains 6 figures and 2 tables.)