Replica-mean-field limits of fragmentation-interaction-aggregation processes

Network dynamics with point-process-based interactions are of paramount modeling interest. Unfortunately, most relevant dynamics involve complex graphs of interactions for which an exact computational treatment is impossible. To circumvent this difficulty, the replica-mean-field approach focuses on randomly interacting replicas of the networks of interest. In the limit of an infinite number of replicas, these networks become analytically tractable under the so-called ‘Poisson hypothesis’. However, in most applications this hypothesis is only conjectured. In this paper we establish the Poisson hypothesis for a general class of discrete-time, point-process-based dynamics that we propose to call fragmentation-interaction-aggregation processes, and which are introduced here. These processes feature a network of nodes, each endowed with a state governing their random activation. Each activation triggers the fragmentation of the activated node state and the transmission of interaction signals to downstream nodes. In turn, the signals received by nodes are aggregated to their state. Our main contribution is a proof of the Poisson hypothesis for the replica-mean-field version of any network in this class. The proof is obtained by establishing the propagation of asymptotic independence for state variables in the limit of an infinite number of replicas. Discrete-time Galves–Löcherbach neural networks are used as a basic instance and illustration of our analysis.

Effect of peripheral iridectomy on VEGF-A and TGF-β levels in rabbit aqueous humour

Background Peripheral iridectomy (PI), routinely performed during glaucoma filtration surgery, may contribute to scarring. This study aims to determine whether PI alters the concentrations of VEGF-A and TGF-β isoforms in the rabbit aqueous humour. Methods Anterior chamber paracentesis (ACP) was performed in both eyes of six New Zealand white rabbits, with additional surgical PI performed in the right eyes. Eyes were examined on postoperative days (PODs) 1, 7, 30 and 60 by means of the tonopen, slit-lamp biomicroscopy, and bead-based cytokine assays for TGF-β and VEGF-A concentrations in the aqueous humor. Results ACP caused a significant reduction in intraocular pressure (IOP) from mean preoperative 11.47 ± 1.01 mmHg to 5.67 ± 1.63 mmHg on POD 1 while PI did not cause further IOP reduction. Limbal conjunctival vasculature appeared slightly increased on POD 1 in both ACP and PI eyes with PI also causing mild bleeding from damaged iris vessels. Two PI eyes developed fibrinous anterior chamber reaction and/ or peripheral anterior synechiae. Aqueous VEGF-A levels were not significantly different between eyes treated with ACP and PI. Aqueous TGF-β concentrations distributed in the ratio of 4:800:1 for TGF-β1:TGF-β2:TGF-β3 respectively. While aqueous TGF-β2 was not significantly induced by either procedure at any time point, TGF-β1 and TGF-β3 were significantly induced above baseline levels by PI on POD 1. Conclusion PI increases the risk of inflammation. The combined induction of aqueous TGF-β1 and TGF-β3 by PI in glaucoma surgery may impact surgery success in glaucoma subtypes sensitive to these isoforms.

So Where Do You See This Going? The Effects of Commitment Asymmetry and Asynchrony on Relationship Satisfaction and Breakup

We test the contribution of multiple types of romantic partners’ commitment asymmetry (discrepancies between partners’ commitment at a single time point) and asynchrony (discrepancies in the progression of commitment over time) to later relationship satisfaction and breakup. In three dyadic studies (N = 6,960 couples) over months (Study 1), days (Study 2), and years (Study 3), commitment asymmetry and asynchrony consistently did not predict satisfaction or breakup when controlling for commitment scores of individuals and their partners. Only one’s own commitment and proportion of downturns in commitment (when participants reported lower commitment than the previous time point) consistently predicted satisfaction across all three studies. For breakup, women’s (but not men’s) commitment was consistently negatively associated with breakup and proportion of downturns was consistently positively associated with breakup. Our findings indicate that, contrary to some significant findings in prior research, commitment asymmetry and asynchrony are not indicative of future relationship outcomes.

A Longitudinal Nonparametric Classification Method for Assessing Change in Latent Attributes Over Time

<p>This study proposed a longitudinal Hamming distance discrimination (Long-HDD) method to improve the application of longitudinal cognitive diagnosis in practical teaching by introducing a simple computation and less time-consuming nonparametric classification method—HDD—into longitudinal diagnostic data processing. Compared with the HDD, the proposed method represents correlation or dependence between adjacent time points of the same student using Hamming distance in anticipation of using information from the previous time point to improve the classification accuracy at the current time point. A simulation study was conducted to explore the performance of the proposed method in longitudinal diagnostic data analysis and to compare the performance of the proposed method with the HDD and a parametric longitudinal diagnostic classification model. The findings suggest that (1) the Long-HDD can provide high classification accuracy in longitudinal diagnostic data analysis; (2) compared with the parametric model, the Long-HDD is almost unaffected by sample size and performs better than the parametric model in small sample sizes; and (3) the Long-HDD consumes much less computing time than the parametric model. Overall, the Long-HDD is well suited to analyzing longitudinal diagnostic data and can provide speedy diagnostic feedback due to its convenient computation, which is especially significant in small-scale assessments at the classroom and school levels.</p>

A Longitudinal Nonparametric Classification Method for Assessing Change in Latent Attributes Over Time

<p>This study proposed a longitudinal Hamming distance discrimination (Long-HDD) method to improve the application of longitudinal cognitive diagnosis in practical teaching by introducing a simple computation and less time-consuming nonparametric classification method—HDD—into longitudinal diagnostic data processing. Compared with the HDD, the proposed method represents correlation or dependence between adjacent time points of the same student using Hamming distance in anticipation of using information from the previous time point to improve the classification accuracy at the current time point. A simulation study was conducted to explore the performance of the proposed method in longitudinal diagnostic data analysis and to compare the performance of the proposed method with the HDD and a parametric longitudinal diagnostic classification model. The findings suggest that (1) the Long-HDD can provide high classification accuracy in longitudinal diagnostic data analysis; (2) compared with the parametric model, the Long-HDD is almost unaffected by sample size and performs better than the parametric model in small sample sizes; and (3) the Long-HDD consumes much less computing time than the parametric model. Overall, the Long-HDD is well suited to analyzing longitudinal diagnostic data and can provide speedy diagnostic feedback due to its convenient computation, which is especially significant in small-scale assessments at the classroom and school levels.</p>

Fleeting: a Novel Ultrasonic Vocalization in Mice That Allows to Define Altered Developmental Milestones in Autism Spectrum Disorder

A major mode of rodent communication occurs through ultrasonic vocalizations (USVs), which are influenced by environmental factors, mouse strain or genetic background and, importantly, by developmental stage. However, few studies have looked into the age-dependent evolution of spectral features of mouse USVs. Here, we report the existence of a novel vocalization, previously unreported, which we named “Fleeting” consisting of two acoustic elements produced with a narrow silent temporal interval between them. Strikingly, this vocalization pattern was extinguished after the second postnatal week, and this temporal pattern was associated with increased emission of Complex vocalizations, by gradual loss of the inter-element interval, suggesting a maturation process occurring at this time point. Importantly, the Fleeting vocalization was analyzed in a mouse model (Tsc2+/-) of Autism Spectrum Disorder (ASD), and showed an abnormal persistence, in particular in females which presented delayed conversion of Fleeting into Complex vocalizations compared with males. The identification of this novel vocalization represents an important insight into the maturation of mouse vocal repertoire and may be used as a developmental milestone in studies on neurodevelopmental disorders with communication impairments.

Efficacy and safety of P11-4 for the treatment of periodontal defects in dogs

Objectives This study’s aim was to investigate the safety and performance of a self-assembling peptide matrix (SAPM) P11-4 for the treatment of periodontal disease in a controlled pre-clinical study. Materials and methods Acute buccal bony dehiscence defects (LxW: 5 × 3 mm) were surgically created on the distal root of four teeth on one mandible side of 7 beagle dogs followed by another identical surgery 8 weeks later on the contralateral side. SAPM P11-4 (with and without root conditioning with 24% EDTA (T1, T2)), Emdogain® (C) and a sham intervention (S) were randomly applied on the four defects at each time point. Four weeks after the second surgery and treatment, the animals were sacrificed, the mandibles measured by micro-computed tomography (µ-CT) and sections of the tissue were stained and evaluated histologically. Results Clinically and histologically, no safety concerns or pathological issues due to the treatments were observed in any of the study groups at any time point. All groups showed overall similar results after 4 and 12 weeks of healing regarding new cementum, functionality of newly formed periodontal ligament and recovery of height and volume of the new alveolar bone and mineral density. Conclusion A controlled clinical study in humans should be performed in a next step as no adverse effects or safety issues, which might affect clinical usage of the product, were observed. Clinical relevance The synthetic SAPM P11-4 may offer an alternative to the animal-derived product Emdogain® in the future.

Simultaneous Descriptors of Research Design

Many students are not aware that research design can be simultaneously described in many different ways; for example, a drug trial may be described as being prospective, longitudinal, randomized, double-blind, and placebo-controlled, all at the same time. This article provides examples to explain how studies can be simultaneously prospective and cross-sectional, prospective and longitudinal, retrospective and cross-sectional, and retrospective and longitudinal. The term prospective indicates that the study data are newly collected, whereas the term retrospective indicates that the study data already exist in records and merely need to be extracted for study. The term cross-sectional indicates that the study subjects are studied on a single occasion; that is, at a single point in time. The term longitudinal indicates that the study subjects are followed up and that there is almost always more than one time point at which the subjects are assessed. This article also describes unusual designs, such as cross-sectional randomized controlled trials and retrospective studies with prospective data ascertainment.

Late arrhythmia recurrence after atrial fibrillation ablation: incidence, mechanisms and clinical implications

Background and objectives Catheter ablation of atrial fibrillation (AF) has become a well-established and widely used therapy, with pulmonary vein isolation (PVI) being the key modality of ablation. However, arrhythmia recurrences after PVI are common, with a relevant number of patients undergoing repeat ablation. Arrhythmia recurrence after PVI may vary regarding time point and mode of recurrence. While early arrhythmia recurrences of AF after PVI are mostly found to be the product of electrical reconnection of the pulmonary veins, the exact mechanisms of very late arrhythmia recurrence, occurring later than 12 months after successful PVI, remain unclear. This review provides an overview on the current evidence on time point and mechanisms of arrhythmia recurrence after PVI focussing on late arrhythmia recurrence. Recent findings The incidence of late arrhythmia recurrence after PVI can lie at a rate of up to 30% according to long-term follow-up studies. Mechanisms of recurrence include electrical reconnection of previously isolated pulmonary veins and development of atrial fibrosis. The use of cryoballoon ablation is likely to be more effective in reducing late arrhythmia recurrences compared to radiofrequency ablation. Novel scores such as the MB-LATER score or the APPLE score may become useful tools in predicting arrhythmia recurrence after PVI. Results and conclusion Late arrhythmia recurrence after PVI is common and leads to a relevant impairment of long-term success. Relevant data are currently limited and exact mechanisms of arrhythmia recurrence remain unclear. Further studies are needed to elucidate pathogenetic mechanisms of late arrhythmia recurrence after PVI in order to improve treatment strategies.

An AI-Enabled Predictive Analytics Dashboard for Acute Neurosurgical Referrals

Healthcare dashboards make key information about service and clinical outcomes available to staff in an easy-to-understand format. Most dashboards are limited to providing insights based on group-level inference, rather than individual prediction. Here, we evaluate a dashboard which could analyze and forecast acute neurosurgical referrals based on 10,033 referrals made to a large volume tertiary neurosciences center in central London, U.K., from the start of the Covid-19 pandemic lockdown period until October 2021. As anticipated, referral volumes significantly increased in this period, largely due to an increase in spinal referrals. Applying a range of validated time-series forecasting methods, we found that referrals were projected to increase beyond this time-point. Using a mixed-methods approach, we determined that the dashboard was usable, feasible, and acceptable to key stakeholders. Dashboards provide an effective way of visualizing acute surgical referral data and for predicting future volume without the need for data-science expertise.