Unmanned aerial vehicle-based sounding of subsurface concrete defects.

A sounding technique that uses an unmanned aerial vehicle (UAV) equipped with two microphones can detect subsurface concrete defects. Use of flexural vibration frequency as a basis for defect depth estimation is evaluated. While many non-destructive tests for concrete can detect depth, current UAV-based inspection methods like optical and thermal imaging are typically limited to two-dimensional subsurface defect information. Acoustic signals from sounding and UAV noise are known to exist in similar frequency ranges. Accordingly, three noise reduction measures for this sounding technique are assessed. Given adequate distance between the microphones and UAV, a two microphone signal subtraction technique is slightly effective for some noise, but a spectral noise gating procedure is shown to substantially decrease noise in the frequency range of interest.

Coblation intracapsular tonsillectomy in a paediatric tertiary centre: Revision surgery rates over a nine-year period.

OBJECTIVES: Coblation intracapsular tonsillectomy (ICT) is increasingly being used in the paediatric population because of the rapid recovery and low rates of complications associated with it. There is, however, a risk of symptomatic regrowth with this technique. The objective of our study is to establish the rate of, and risks for, revision surgery over time in a major tertiary referral centre with a large cohort of paediatric Coblation ICT cases. METHODS: A retrospective review of all children (0-19 years) undergoing Coblation ICT from April 2013 to June 2022 was undertaken, using electronic databases and clinical records. Post-operative follow up was reviewed and revision cases were subsequently identified and examined. Statistical analysis was performed using a Chi-Squared test. RESULTS: 4111 patients underwent Coblation ICT during the studied period, with or without concomitant adenoidectomy. Of these, 135 (3.3 %) required revision tonsil surgery, primarily for recurrence of initial symptoms; two patients required two consecutive revision procedures (137 revision procedures in total). Eight-eight (n = 88) (64 %) of these were revised with a repeat Coblation ICT procedure and 49 (36 %) with bipolar diathermy extracapsular tonsillectomy (ECT) of remnant tonsil tissue. The revision rates after Coblation ICT declined steeply on a year-on-year basis since the commencement of this technique (from 10.6 % early on, to 0.3 % at the end of the study period P<0.001). A significantly higher revision rate was noted in children below the age of two at the time of primary surgery, compared to those older than two years of age (P<0.001). CONCLUSIONS: This study demonstrates real-world departmental revision rates over a nine-year period from the technique's commencement of use. With Coblation ICT, symptomatic re-growth occurs rarely, but may be clinically significant, with higher rates of recurrent symptoms seen in children under two years of age at the time of primary surgery. The revision rate apparently drops over time in parallel with overall experience of surgeons and formalised training.

Travel Tales of a Worldwide Weed: Genomic Signatures of Plantago major L. Reveal Distinct Genotypic Groups With Links to Colonial Trade Routes.

Retracing pathways of historical species introductions is fundamental to understanding the factors involved in the successful colonization and spread, centuries after a species' establishment in an introduced range. Numerous plants have been introduced to regions outside their native ranges both intentionally and accidentally by European voyagers and early colonists making transoceanic journeys; however, records are scarce to document this. We use genotyping-by-sequencing and genotype-likelihood methods on the selfing, global weed, Plantago major, collected from 50 populations worldwide to investigate how patterns of genomic diversity are distributed among populations of this global weed. Although genomic differentiation among populations is found to be low, we identify six unique genotype groups showing very little sign of admixture and low degree of outcrossing among them. We show that genotype groups are latitudinally restricted, and that more than one successful genotype colonized and spread into the introduced ranges. With the exception of New Zealand, only one genotype group is present in the Southern Hemisphere. Three of the most prevalent genotypes present in the native Eurasian range gave rise to introduced populations in the Americas, Africa, Australia, and New Zealand, which could lend support to the hypothesis that P. major was unknowlingly dispersed by early European colonists. Dispersal of multiple successful genotypes is a likely reason for success. Genomic signatures and phylogeographic methods can provide new perspectives on the drivers behind the historic introductions and the successful colonization of introduced species, contributing to our understanding of the role of genomic variation for successful establishment of introduced taxa.

Treatment of severe tracheobronchomalacia: Ten-year experience.

INTRODUCTION: Paediatric tracheobronchomalacia is a rare but potentially serious condition. Severe tracheobronchomalacia requires intervention or operation. This is an evaluation of a ten-year experience at an institution. METHODS: In this retrospective study all patients were included that required an intervention for severe tracheobronchomalacia from 2003 to 2012. Symptoms, aetiology, comorbidities, localisation of the malacia, age at diagnosis, therapeutic measures and associated complications were evaluated. RESULTS: Forty-four patients with severe tracheobronchomalacia underwent intervention/operation. The predominant aetiology was vascular compression in 48%. The majority of patients had complex comorbidities, most importantly cardiac pathology in 66%. The median age at diagnosis was 3 months. A total of 17 aortopexies, 21 tracheostomies and 25 stent placements were performed. The mean follow-up was 2.6 years. Severe complications occurred in 12 patients. The most common complications were stent obstruction/fracture and tracheostomy tube obstruction. CONCLUSION: The management of severe tracheobronchomalacia is complex and the population of patients is very heterogeneous. Therefore the treatment has to be adapted for each patient individually. The decision strategies are discussed in this article. The surgical techniques for placement and safe removal of expandable bare metallic stents employed in our institution are presented. A multidisciplinary team of ENT surgeons, Intensivists, Cardiologists and Cardiac surgeons is of great importance.

Twitch airway pressure elicited by magnetic phrenic nerve stimulation in anesthetized healthy children.

Children with diaphragm dysfunction may be unable to maintain adequate ventilation. Accurate diagnosis is important, but can only be achieved using an appropriate test and reference range. The aim of this study, therefore, was to measure diaphragm contractility and examine the influence of age and maturation, using magnetic phrenic nerve stimulation in healthy children. Anterolateral magnetic stimulation (MS) of the phrenic nerves was performed using a 43-mm figure-eight coil in 23 children (14 male; mean age, 7.8 years; range, 1.8-15.7) anesthetized for minor surgery with sevoflurane gas. The airway was maintained with a cuffed laryngeal mask airway (LMA) which was briefly occluded during MS. Diaphragm contractility was assessed by measuring the airway pressure (TwPaw) elicited by MS. TwPaw responses were obtained in all subjects, with mean (SD) TwPaw 18.2 (6.8) cm H2O bilateral, 7.3 (3.2) cm H2O left unilateral, and 8.6 (3.1) cm H2O right unilateral. Subgroup analysis was performed in 17 of the children who were prepubertal. Their mean (SD) TwPaw was 17.3 (6.8) cm H2O bilateral, 7.1 (3.7) cm H2O left unilateral, and 8.3 (3.3) right unilateral. The mean (SD) intrapatient coefficients of variation for bilateral and left and right unilateral TwPaw were 8.4% (5.2), 6.7% (3.5), and 11.7% (10.3), respectively. Bilateral and left and right unilateral TwPaw were significantly related to age (P < 0.05). In healthy prepubertal children, diaphragm contractility is primarily influenced by age.

A third branchial pouch cyst presenting as stridor in a child.

We present a rare case of a third branchial pouch cyst in an 18-month-old child, presenting with stridor and a lateral cervical cystic mass. Differences in the anatomical course of third and fourth branchial cysts, and histological differences between branchial pouch and branchial cleft cysts are discussed.

Anesthetic management of the complications of previously undiagnosed ingested foreign body in a pediatric patient.

A case of a previously undiagnosed ingested foreign body, subsequent acquired tracheoesophageal fistula and airway obstruction in a pediatric patient is described. We suggest that the capability to provide cardiopulmonary bypass was a key factor in this patient's survival.