An optimal admission control protocol for heterogeneous multicast streaming services

We investigate optimal call admission control (CAC) policy for multicast streaming services (MSS) in 3rd generation (3G) and beyond wireless mobile networks. Several MSS sessions are supported simultaneously in a bandwidth-limited network. Active sessions are those that are currently serving some users, and inactive sessions are those that are currently not serving any users. An admission decision in MSS is required only when an inactive session is requested, unlike in unicasting. For this reason, if a user request for an inactive MSS session arrives, we should make an admission decision in anticipation of (i) the possible reward earned based on users served during a session active time generated by accepting it, and (ii) the influence of the session active time upon the future status of network bandwidth and admission decisions. Our objective is to determine when to admit or block a user asking an inactive MSS session to achieve the optimality in rewards. We formulate this problem as a semi-Markov decision process (SMDP), and a value iteration algorithm is used to obtain an optimal stationary deterministic policy. We also derive the user blocking probability of the optimal policy by analyzing an embedded Markov chain induced by it.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=26hb201

Review article: faecal incontinence in children: epidemiology, pathophysiology, clinical evaluation and management

Faecal incontinence (FI) in children is a significant gastrointestinal problem, with great personal and social impacts. It is characterised by recurrent loss of faecal matter into the underwear. Both functional and organic causes contribute to its aetiology with the former predominating. To review the epidemiology, pathophysiology, clinical evaluation and management of functional faecal incontinence in children. A PubMed search was conducted using search terms f(a)ecal incontinence, and encopresis. Articles on epidemiology, pathophysiology, clinical evaluation, investigation and management of functional FI in children were retrieved and assessed. Community prevalence of this distressing problem ranges from 0.8% to 7.8% globally. Male: female ratio varies from 3:1 to 6:1. The diagnosis of FI is often based on established clinical criteria. The majority (82%) have constipation associated functional FI. Biopsychosocial factors play a crucial role in the pathogenesis. Limited physiological testing of anorectal function is recommended in the diagnostic procedures, particularly in children with atypical symptoms and possible organic disorders. Management of FI needs a multidisciplinary approach which includes establishment of an effective doctor-patient partnership, understanding the underlying mechanisms, pharmacotherapy and behavioural treatment. Approximately 15% of children with functional nonretentive faecal incontinence (FNRFI) had the same symptoms at the age of 18 years. Significant therapeutic advances have been made for retentive faecal incontinence, but treatment options for functional nonretentive faecal incontinence are limited. Limited long-term outcome data show that the majority outgrow faecal incontinence. A substantial proportion of children progress to adulthood with faecal incontinenc

Rumination syndrome in children and adolescents: a school survey assessing prevalence and symptomatology

<p>Abstract</p> <p>Background</p> <p>Rumination syndrome (RS) is a functional gastrointestinal disorder (FGD) increasingly recognized in children and adolescents. The epidemiology of this condition in school aged children is poorly understood. The main objective of this study was to assess the prevalence of rumination and other related associations in a cohort of Sri Lankan children.</p> <p>Methods</p> <p>Children aged 10-16 years were randomly selected from 8 schools in 4 provinces in Sri Lanka. RS was diagnosed using Rome III criteria. Data was collected using a self administered questionnaire distributed in an examination setting. It was translated into Sinhala, the native language and pretested before distribution.</p> <p>Results</p> <p>A total of 2163 children were included in the study (55% boys, mean age 13.4 years, SD 1.8 years). Prevalence of RS was 5.1% (<it>n</it> = 110); boys 5.1% and girls 5.0%. When symptoms were analyzed, 73.6% reported re-swallowing of regurgitated food, while the rest spat it out. In 94.5% regurgitation occurred during the first hour after the meal. Only 8.2% had daily symptoms while 62.7% had symptoms weekly. Abdominal pain, bloating and weight loss were the commonest symptoms associated with RS (19.1%, 17.3% and 11.8% respectively). No significant association was observed between exposure to stressful events and rumination (<it>p</it> > 0.05). Twenty (18.2%) with RS fulfilled Rome III criteria for at least one other FGD. School absenteeism was seen in 11.8% of affected children.</p> <p>Conclusion</p> <p>RS was reasonably common in this cohort of school-aged children and adolescents in Sri Lanka. However, symptoms were severe enough to affect schooling only in 12% of affected children. Around one fifth with RS had at least one other overlapping FGD.</p

Quality of Life in Children with Functional Constipation: A Systematic Review and Meta-Analysis

Objective: To systematically review the literature on health-related quality of life (HRQoL) in children with functional constipation and to identify disease-related factors associated with HRQoL. Study design: The Pubmed, Embase, and PsycINFO database were searched. Studies were included if they prospectively assessed HRQoL in children with functional constipation according to the Rome criteria. Articles were excluded if patients had organic causes of constipation and if HRQoL was only assessed after successful therapeutic interventions. A meta-analysis was performed calculating sample size–weighted pooled mean and SD of HRQoL scores. The quality of the studies was also assessed. Results: A total of 20 of 2658 studies were included, providing HRQoL data for 2344 children. Quality of evidence was considered to be poor in 9 of the 20 studies (45%); 13 of the 20 studies reported sufficient data to be included in the meta-analysis. Pooled total HRQoL scores of children with functional constipation were found to be lower compared with healthy reference samples (65.6 vs 86.1; P < .01). Similar HRQoL scores were found according to self-report and parent proxy report. Hospital-based studies reported lower HRQoL scores as compared with community-based studies. Two studies reported on HRQoL scores of children with and without fecal incontinence, but no significant difference was found. Conclusions: HRQoL is compromised in children with functional constipation

A Core Outcome Set for Clinical Trials in Pediatric Functional Abdominal Pain Disorders

Objective: To ensure consistency and reduce outcome measure reporting heterogeneity in clinical trials on pediatric functional abdominal pain disorders (FAPDs), a core outcome set (COS) was developed for pediatric FAPD trials. Study design: A mixed-method 2-round Delphi technique was used and key stakeholders, including healthcare professionals (HCPs), patients with FAPD, and their parents were invited to participate. In the first round, key stakeholders identified outcomes of importance through an open-ended questionnaire. Outcomes mentioned by ≥10% of the participants were included in a shortlist. In the second round, this shortlist was rated and prioritized. During a consensus meeting with an expert panel, the final COS was defined. Results: The first round was completed by 152 of 210 (72%) HCPs, 103 (100%) parents, and 50 of 54 (93%) patients. A total of 104 from 167 (62%) HCPs, 102 (100%) parents, and 53 (100%) patients completed round 2. Pain intensity, pain frequency, quality of life, school attendance, anxiety/depression, adequate relief, defecation pattern (disease specific, irritable bowel syndrome), and adverse events were included in the final COS for FAPDs. Conclusion: A set of 8 core outcomes has been identified that should minimally be measured in pediatric FAPD trials. Implementation of the use of this COS will increase comparison between studies and, therefore, improve management of children with FAPDs