Electrocardiographic variables in children with syndromic craniosynostosis and primary snoring to mild obstructive sleep apnea

Background: In the spectrum of children with symptomatic sleep disordered breathing (SDB), some individuals – such as those with upper airway resistance syndrome (UARS) – do not have abnormalities on polysomnography (PSG). In this study we have assessed whether assessment of respiratory arrhythmia (RA) and heart rate variability (HRV) analysis helps in management of children with syndromic craniosynostosis and none-to-mild obstructive sleep apnea (OSA). Methods: Prospective cohort study in children aged 1–18 years old with syndromic craniosynostosis. Children were selected for HRV analysis from the ECG if their obstructive apnea–hypopnea index (oAHI) was between zero and five per hour (ie, oAHI ≤5/hour). Subjects were divided into groups based on the presence or absence of respiratory arrhythmia (with or without RA respectively) using the electrocardiogram (ECG). The main analysis included studying the relationship between RA and HRV, symptoms, interventions, and sleep architecture. Results: We identified 42 patients with, at worst, mild OSA. We found higher parasympathetic control and higher total power in children with RA during the non-rapid eye movement (non-REM) sleep. Children with RA also have a relatively higher percentage of paradoxical breathing during non-REM sleep (P = 0.042). Intracranial hypertension was distributed equally between groups. Last, RA patients showed increased parasympathetic activity that further increased in non-REM sleep. Conclusion: In syndromic craniosynostosis cases with SDB and PSG showing oAHI ≤5/hour, the presence of RA may indicate subsequent need for treatment interventions, and a trend toward higher occurrence of clinical symptoms. ECG analyses of HRV variables in subjects with RA demonstrate increased parasympathetic activity and total power. Such findings may add to the diagnosis of apparently asymptomatic children

DIALIGN-TX and multiple protein alignment using secondary structure information at GOBICS

We introduce web interfaces for two recent extensions of the multiple-alignment program DIALIGN. DIALIGN-TX combines the greedy heuristic previously used in DIALIGN with a more traditional ‘progressive’ approach for improved performance on locally and globally related sequence sets. In addition, we offer a version of DIALIGN that uses predicted protein secondary structures together with primary sequence information to construct multiple protein alignments. Both programs are available through ‘Göttingen Bioinformatics Compute Server’ (GOBICS)

DIL Symposium Program Development Exercise: Physical Sciences/Chemistry

The NP-hard Colorful Components problem is, given a vertex-colored graph, to delete a minimum number of edges such that no connected component contains two vertices of the same color. It has applications in multiple sequence alignment and in multiple network alignment where the colors correspond to species. We initiate a systematic complexity-theoretic study of Colorful Components by presenting NP-hardness as well as fixed-parameter tractability results for different variants of Colorful Components. We also perform experiments with our algorithms and additionally develop an efficient and very accurate heuristic algorithm clearly outperforming a previous min-cut-based heuristic on multiple sequence alignment data

Characteristics and outcomes in children with congenital central hypoventilation syndrome on long-term mechanical ventilation in the Netherlands

UNLABELLED: Congenital central hypoventilation syndrome (CCHS) is a rare condition characterized by central hypoventilation, leading to the majority of patients being dependent on ventilatory support during sleep. This condition is often accompanied by various associated symptoms, due to a PHOX2B gene variant involved in neuronal crest cell migration. This study is the first to review the characteristics and outcomes in children with CCHS on long-term mechanical ventilation in the Netherlands. We performed a retrospective study of all CCHS patients treated in the 4 Centers of Home Mechanical Ventilation of the University Medical Centers in the Netherlands from 2000 till 2022 by collecting information from the electronic medical records, documented during follow-up. We included 31 patients, out of which 27 exhibited a known genetic profile associated with CCHS, while no PHOX2B variant was identified in the remaining patients. Among the 27 patients with known genetic profiles, 10 patients had a non-polyalanine repeat expansion mutation (NPARM), followed by 20/27, 20/25, and 20/26 polyalanine repeat expansion mutations (PARMs) in descending order. The most common presentation involved respiratory failure or apneas during the neonatal period with an inability to wean off ventilation. The majority of patients required ventilatory support during sleep, with four patients experiencing life-threatening events related to this dependency. Daily use of ventilatory support varied among different genetic profiles. All genotypes reported comorbidities, with Hirschsprung's disease and cardiac arrhythmias being the most reported comorbidities. Notably, Hirschprung's disease was exclusively observed in patients with a 20/27 PHOX2B variant. CONCLUSION: Our study results suggest that in our cohort, the genotype is not easily associated to the phenotype in CCHS. Consistent with these findings and international literature, we recommend a thorough annual evaluation for all patients with CCHS to ensure optimal management and follow-up. WHAT IS KNOWN: • The majority of CCHS patients are dependent on ventilatory support. • Variants in the PHOX2B gene are responsible for the characteristics of CCHS. WHAT IS NEW: • This study provides insight into the clinical course and long-term outcomes of CCHS patients in the Netherlands. • In CCHS, the genotype is not easily associated with the phenotype, requiring a thorough life-long follow-up for all patients

Evaluation of ILP-Based Approaches for Partitioning into Colorful Components

The NP-hard Colorful Components problem is a graph partitioning problem on vertex-colored graphs. We identify a new ap-plication of Colorful Components in the correction of Wikipedia interlanguage links, and describe and compare three exact and two heuristic approaches. In particular, we devise two ILP formulations, one based on Hitting Set and one based on Clique Partition. Furthermore, we use the recently proposed implicit hitting set framework [Karp, JCSS 2011, Chandrasekaran et al., SODA 2011] to solve Colorful Components. Finally, we study a move-based and a merge-based heuristic for Col-orful Components. We can optimally solve Colorful Components for Wikipedia link correction data; while the Clique Partition-based ILP outperforms the other two exact approaches, the implicit hitting set is a simple and competitive alternative. The merge-based heuristic is very accurate and outperforms the move-based one. The above results for Wikipedia data are confirmed by experiments with synthetic instances

Maximum colorful cliques in vertex-colored graphs

International audienceIn this paper we study the problem of finding a maximum colorful clique in vertex-colored graphs. Specifically, given a graph with colored vertices, we wish to find a clique containing the maximum number of colors. Note that this problem is harder than the maximum clique problem, which can be obtained as a special case when each vertex has a different color. In this paper we aim to give a dichotomy overview on the complexity of the maximum colorful clique problem. We first show that the problem is NP-hard even for several cases where the maximum clique problem is easy, such as complement graphs of bipartite permutation graphs, complement graphs of bipartite convex graphs, and unit disk graphs, and also for properly vertex-colored graphs. Next, we provide a XP parameterized algorithm and polynomial-time algorithms for classes of complement graphs of bipartite chain graphs, complete multipartite graphs and complement graphs of cycle graphs, which are our main contributions