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Numerical simulations of the geodynamo have successfully represented many observable characteristics of the geomagnetic field, yielding insight into the fundamental processes that generate magnetic fields in the Earth's core. Because of limited spatial resolution, however, the diffusivities in numerical dynamo models are much larger than those in the Earth's core, and consequently, questions remain about how realistic these models are. The typical strategy used to address this issue has been to continue to increase the resolution of these quasi-laminar models with increasing computational resources, thus pushing them toward more realistic parameter regimes. We assess which methods are most promising for the next generation of supercomputers, which will offer access to O(106) processor cores for large problems. Here we report performance and accuracy benchmarks from 15 dynamo codes that employ a range of numerical and parallelization methods. Computational performance is assessed on the basis of weak and strong scaling behavior up to 16,384 processor cores. Extrapolations of our weak-scaling results indicate that dynamo codes that employ two-dimensional or three-dimensional domain decompositions can perform efficiently on up to ∼106 processor cores, paving the way for more realistic simulations in the next model generation.

Presents a study determining the effect of the Magenstrasse & Mill non-banded gastroplasty on the lower esophageal sphincter (LOS) in obese patients. Performance of three-dimensional manometry; Report of heartburn after surgery; Increase of LOS pressure.

Introduction: The treatment of large renal stones (≥1 cm) in paediatric patients is challenging. The usual treatment options include percutaneous nephrolithotomy (PCNL) or shockwave lithotripsy (SWL). There is a rise in the use of ureteroscopy and laser stone fragmentation (URSL) for paediatric stones; however, outcomes of treatment for large renal stones in this age group are still largely unknown., Objective: To investigate the outcome of URSL for large paediatric renal stones ≥1 cm treated at the present institution over the last 5 years., Methods: A retrospective review was performed of outcomes from the prospectively maintained stone database. Only paediatric patients undergoing ureteroscopic (rigid or flexible ureteroscopy (URS)) procedures for stones ≥1 cm were included. Patient demographics, operative details, stone burden, hospital stay, complications and stone clearance were recorded and analysed., Results: From April 2010 to June 2015, 18 paediatric patients with a mean age of 10.4 years (range 3.6-15) underwent 35 ureteroscopic procedures for large stones (≥1 cm). The stone location was in the kidney (n = 14), ureter (n = 1), and in both the kidney and ureter for the remaining three patients. Nine patients had multiple stones. There was a preceding history of PCNL in four patients, with one patient having URS combined with a PCNL. The mean follow-up was 2.7 years (range 0-5). A postoperative stent was inserted in 21 (60%) patients. The overall stone-free rate (SFR) was 89% for a mean of 1.8 procedures per patient (range 1-4) - see Summary Table below. There was an inability to access stone within a lower pole calyx in one patient, despite maximum deflection of the ureteroscope. No intra- or post-operative complications were noted, and mean hospital stay was 1.1 days (range 0-5)., Discussion: Published papers in adult literature have shown that ureteroscopy and laser fragmentation (URSL) is a viable alternative to PCNL. Newer equipment and improved techniques have resulted in SFRs being comparable with PCNL. A recent systematic review reported an SFR of 91% for large adult stones (>2 cm) for a mean 1.45 procedures per patient, and an overall complication rate of 8.6%. The present study has also demonstrated excellent outcomes in the use of ureteroscopy and laser fragmentation for the management of large paediatric stones with no complications., Conclusion: The results show that paediatric URSL for large stones achieves a good SFR with minimal morbidity and is a good treatment option in established endourological units., (Copyright © 2016. Published by Elsevier Ltd.)

Purpose: Antegrade continence enema (ACE) revolutionised the lives of children with chronic constipation and soiling. Parents often ask how long the ACE will be required. We looked at our patients 5 years after ACE formation to answer the question., Methods: We reviewed clinical notes of all patients undergoing ACE procedure during January 1990 to December 2010. Only patients with >5 years follow-up were included. Data are given as median (range)., Results: 133 patients were included with >5 years of follow-up. Primary pathology was anorectal anomaly (ARA) 64 (48%); spinal dysraphism (SD) 40 (30%); functional constipation (FC) 14 (10%); Hirschsprung's Disease (HD) 10 (8%) and others 5 (4%). Median follow-up was 7 years (5-17 years). Overall 74% still use their ACE; whilst 26% no longer access their stoma, of whom 47% recovered normal colonic function. 50% of HD patient recover colonic function. FC has the highest failure rate at 21%., Conclusions: Overall 86% achieved excellent clinical outcome with 74% of patient still using their ACE at 5 years. HD has the highest recovery rate of 50%. FC has a more unreliable clinical outcome with 21% recovered colonic function and 21% failed. Outcome varied dependent on the background diagnosis.

Objective: To determine whether the adrenoceptor agonist, ephedrine hydrochloride, is an effective treatment for resistant non-neurogenic daytime urinary incontinence in children., Methods: From 2000 to 2010, eighteen children with resistant non-neurogenic daytime urinary incontinence were treated with oral ephedrine hydrochloride at our institution. Sixteen were female and two were male. Median age at treatment was 12 years (range 5-15 years). Two children had spina bifida occulta. There were no other co-morbidities. Multiple anticholinergics were prescribed and dose maximized to support a bladder and bowel training programme, without achieving continence in this resistant group of children. Pre-treatment urodynamics were normal in 10, but revealed an open bladder neck in 8 patients. None showed detrusor over-activity. Oral ephedrine hydrochloride was started at 7.5 mg or 15 mg twice daily and titrated up to a maximum of 30 mg four times daily according to response., Results: Median follow-up was 7 years (range 6-8 years). Seventeen children (94%) reported improvement in symptoms and six (33%) achieved complete urinary continence. All patients maintained compliant bladders on post-treatment urodynamics. Seven of the 8 previously open bladder necks were closed. No patients reported any significant side effects. Patients with open bladder necks on pre-treatment urodynamics were more likely to show a full response to ephedrine (odds ratio 15; 95% CI 1.2-185.2)., Conclusions: Oral ephedrine hydrochloride is an effective treatment for carefully selected children with resistant non-neurogenic daytime urinary incontinence., (Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Background: Idiopathic intussusception is one of the most common causes of small bowel obstruction in children. In the event of failed radiological reduction, laparotomy remains the treatment of choice. There is still no agreement in pediatric surgery about safety and effectiveness of the use of minimally invasive surgery in this common pediatric condition. By reviewing available data we aimed to establish whether laparoscopy should be the primary technique in the surgical reduction of intussusception., Methods: A systematic review of all publications on the laparoscopic treatment of pediatric intussusception from January 1990 to April 2012 was performed. The following variables were analyzed: age, laparoscopic success rate, reason for conversion, enterotomy rate, operative time, complications, and length of stay (LOS)., Results: Ten retrospective studies treating 276 cases of laparoscopically reduced intussusception were identified. A total of 80 conversions corresponded to a 71.0% laparoscopic success rate. Only one case of intraoperative iatrogenic intestinal perforation was reported (0.4%). Postoperative complications occurred in 8 patients (2.9%), and adhesive small bowel obstruction was reported in 1 case (0.4%). Recurrence rate after laparoscopy was 3.6%. Three of 10 papers compared results between laparoscopic and open reduction of intussusception showing a shorter mean LOS in the former group (4.0 vs. 7.1 days, p<0.01)., Conclusion: Laparoscopy is safe and effective in the treatment of pediatric intussusception. Tertiary centers with adequate minimally invasive skills should establish laparoscopy as the primary surgical technique in the treatment of this condition., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We report a case of a 7-year-old boy with a voluminous 8.5-cm "cobra-head" calculus in a duplex system ureterocele causing flank pain, hematuria, and infection. Combined cysto-ureteroscopy and percutaneous cystolithotomy enables dependent ureterocele incision along its inferolateral border and efficient stone clearance in a single minimally invasive procedure. Protracted and repeated urethral instrumentation is avoided.

Paediatric surgeons commonly evaluate acute scrotal pain. Previous peer review articles have suggested that boys should be educated to ensure early medical assessment thereby avoiding potential testicular loss. In this study we sought to ascertain a contemporary view of educational awareness of testicular pain in boys presenting to our service. A prospective 11 month study of boys attending our unit with acute scrotal pain was undertaken. Additionally, 30 consecutive patients completed a standardised questionnaire to ascertain their educational awareness of testicular pain. A total of 84 boys were referred to our service for evaluation of acute scrotal pain; 36 required operative interventions. Nine patients (25%) had testicular torsion; 19 patients (52.8%) had torted appendages; 6 patients (16.7%) had epididymitis and 2 patients (5.5%) had alternative diagnoses. There was one case of testicular loss in the older age group. Most boys were unaware of testicular problems but felt an education regarding scrotal problems would be useful. Our study shows that an unawareness of testicular pain exists in both children and their carers. We envisage that including basic educational aspects into the school curriculum may help avoid possible testicular loss in the future.

Background: The indications for partial or total nephrectomy for urological reasons are not clearly documented in the paediatric surgical literature and there are only a limited number of publications on this subject., Purpose: In order to clarify the situation in our centre, we reviewed our own indications for nephrectomy over a 20-year period., Methods: Medical records of patients who underwent nephrectomy for urological and oncological causes between May 1990 and October 2010 at our centre were retrospectively reviewed. Indications for nephrectomy were noted. Renal function was noted for urological cases., Results: A total of 357 nephrectomies were undertaken; out of these, 241 cases were for urological causes and 116 for oncological reasons. The majority of total nephrectomies were performed for multicystic dysplastic kidneys, reflux nephropathy, pelvi-ureteric junction obstruction and dysplasia. Eighty-seven patients exhibited no function at the time of nephrectomy. Of the remainder, 17 had <5% function, 18 had 5-10% function, 5 had 10-15% function and 2 patients had 15-20% function., Conclusions: This is the largest series of nephrectomies in the paediatric surgery literature to date. The majority of nephrectomies were undertaken for urological conditions with relative renal function of <10% and could not have been usefully preserved in situ. We suggest that kidneys with >10% function should not be routinely removed.

Bacillus thuringiensis endotoxins (Bt-toxins) are the most important biopesticides used in controlling insect pests and vectors of diseases. The emergence of widespread resistance to Bt in some insect species is a serious threat to agricultural production. Analysis of Bt-resistant and susceptible laboratory strains of Helicoverpa armigera revealed elevated immune responses involving increased melanization and the presence of a soluble toxin-binding glycoprotein in the hemolymph and gut lumen of the resistant strain. We propose a resistance mechanism against toxins based on a systemic immune-induction that can be transmitted to the next generation by a maternal effect.

The importance of examiner familiarity to children's performance on tasks requiring high or low levels of symbolic mediation was investigated. Thirty-four handicapped preschool children were examined within a repeated measures crossover design, once by one of two familiar classroom teachers and once by one of four strange teachers. Subjects performed significantly better with familiar than with unfamiliar examiners on high symbolic mediation tasks; no such differential performance was obtained on low symbolic mediation items. Findings are related to current efforts to identify procedural and situational variables in assessment, uncontrolled by present standard test administrations, that may preclude children's optimal performance.