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African White-backed Vultures were recently uplisted to ‘Critically Endangered’ by IUCN due to declines across their range. Poisoning is widely accepted as the major reason for these declines. Botswana supports a high number of this species (breeding pairs > c.1,200), but as yet no published information exists on their breeding success in the country. However, mass poisonings within Botswana and neighbouring countries have killed thousands of White-backed Vultures in recent years. We therefore expected that nesting numbers may have declined in this region if these poisoning events killed local breeding birds. We used information from aerial surveys conducted between 2006 and 2017 in Khwai and Linyanti, two important breeding areas for this species in north-central Botswana, to determine if there was any change in nesting numbers and breeding success of White-backed Vultures. Results showed an overall 53.5% decline in nesting numbers, with a greater decline in Linyanti than in Khwai. In both areas, breeding success was significantly lower in 2017 than it was 10 ten years earlier. We recommend that similar repeat surveys are continued to provide greater confidence in the trends of both nesting numbers and breeding performance. Population viability analysis suggested that if the productivity levels detected in 2017 were a true indication of current productivity levels for this population, and if recent high poisoning rates continue, this population could be extirpated from the area in the next 13 years.
Background: Cerebellar atrophy is characterized by loss of cerebellar tissue, with evidence on brain imaging of enlarged interfolial spaces compared to the foliae. Genetic ataxias associated with cerebellar atrophy are a heterogeneous group of disorders. We investigated the prevalence in Canada and the diagnostic yield of whole exome sequencing (WES) for this group of conditions. Methods: Between 2011 and 2017, WES was performed in 91 participants with cerebellar atrophy as part of one of two national research programs, Finding of Rare Genetic Disease Genes (FORGE) or Enhanced Care for Rare Genetic Diseases in Canada (Care4Rare). Results: A genetic diagnosis was established in 58% of cases (53/91). Pathogenic variants were found in 24 known genes, providing a diagnosis for 46/53 participants (87%), and in four novel genes, accounting for 7/53 cases (13%). 38/91 cases (42%) remained unsolved. The most common diagnoses were channelopathies in 12/53 patients (23%) and mitochondrial disorders in 9/53 (17%). Inheritance was autosomal recessive in the majority of cases. Additional clinical findings provided useful clues to some of the diagnoses. Conclusions: This is the first report on the prevalence of genetic ataxias associated with cerebellar atrophy in Canada, and the utility of WES for this group of conditions.
Mosquito communities across the globe frequently comprise a mix of native and cosmopolitan species. New Zealand's mosquito communities are no exception. Here we describe the abundance, distribution and phenological patterns for a community of six mosquito taxa resident across the Kaipara Harbour region of northern New Zealand. Adult mosquitoes were sampled using baited light traps, serviced biweekly for 3½ years. Seasonal fluctuations in abundance of adults were examined for correlations with temperature and rainfall over the preceding weeks. Four endemic species comprised over 98% of the total catch, with Coquillettidia iracunda being the most abundant. Two introduced species, Aedes notoscriptus and Culex quinquefasciatus were widely distributed, but each comprised <1% of the total catch. Culiseta tonnoiri was the only species that appeared geographically restricted, occurring at one-third of the sites. Distinct temporal peaks in adult abundance were evident: Aedes antipodeus was most abundant in spring, Ae. notoscriptus and Cq. iracunda were most abundant in summer and Cx. quinquefasciatus was most abundant in autumn. Culiseta tonnoiri and Culex pervigilans were of variable abundance throughout the year. For all species examined, temporal variations in abundance were more strongly associated with temperature in the preceding weeks than with preceding rainfall. A better knowledge of the factors driving patterns of spatial and temporal abundance will allow an improved understanding of how non-native species may integrate themselves into resident mosquito communities.
To describe our experience and provide guidelines for maximum safe balloon sizes according to age in children undergoing balloon dilatation.
A retrospective review was conducted of children undergoing balloon dilatation for subglottic stenosis in a paediatric tertiary unit between May 2006 and February 2016.
A total of 166 patients underwent balloon dilatation. Mean ( ± standard deviation) patient age was 4.5 ± 3.99 years. The median balloon size was 8 mm, the median balloon inflation pressure was 10 atm, and the mean balloon inflation time was 65.1 ± 18.6 seconds. No significant unexpected events occurred. The Pearson correlation co-efficient for the relationship between patient age and balloon size was 0.85 (p = 0.001), suggesting a strongly positive correlation.
This study demonstrated that balloon dilatation is a safe procedure for airway stenosis. The results suggest using a balloon diameter that is equal to the outer diameter of the age-appropriate endotracheal tube +1 mm for the larynx and subglottis and +2 mm for the trachea.
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
Migratory fishes are natural wonders. For many people, the term migratory fish evokes images of salmon audaciously jumping at waterfalls as they return to their own riverine birthplace to spawn after years of growth in the ocean, but freshwater fishes actually show a broad spectrum of migration strategies. Migratory fishes include small species – three-spined sticklebacks that spawn in coastal streams around the northern Pacific and gobies that move from the ocean into tropical island streams by climbing waterfalls (McDowall, 1988) – as well as some of the largest freshwater fishes in the world, such as the Mekong dog-eating catfish and the Chinese paddlefish (Stone, 2007). Aside from migratory habits, these species have few shared characteristics; they encompass numerous evolutionary lineages, enormous differences in life history, and every possible direction and distance of migration. Biologists treat migratory freshwater fishes as a functional group because their life-history strategy revolves around long-distance movement between ecosystems in a perilous quest to take advantage of both high-quality breeding sites and bountiful feeding areas. As humans have physically blocked fish migrations, degraded breeding and feeding grounds and relentlessly harvested migrants for their flesh and roe, many populations have declined or been extirpated. This chapter will provide an overview of fundamental and applied research that is helping to guide efforts to conserve migratory freshwater fishes.
For practical purposes, we define migratory behaviour as the synchronized movement of a substantial proportion of a population between distinct habitats, which is repeated through time within or across generations. Modern definitions of fish migrations typically recognise both the adaptive benefits of migrating and individual variation in executing the general strategy (see McDowall, 1988; Lucas & Baras, 2001). Not every individual must move, the timing may vary somewhat from year to year, and the motive for migrating may include seeking refuge from harsh conditions in addition to breeding and feeding. Nonetheless, in most cases, migration is critical to individual fitness and population persistence because it enables specialised use of different habitats for growth and reproduction. Where their migration routes are blocked or key habitats are lost, migratory fishes often suffer rapid and catastrophic losses.
Human appropriation and degradation of the Earth's freshwater ecosystems (Vörösmarty et al., 2010; Carpenter et al., 2011) have transformed this reliance on multiple habitats into a detriment for many migratory fishes.
Treatment options for large subglottic haemangioma include steroids, laser ablation, open excision, tracheostomy and, more recently, propranolol. This article aims to present the Great Ormond Street Hospital guidelines for using propranolol to treat infantile isolated subglottic haemangioma by ENT surgeons.
The vascular malformations multidisciplinary team at Great Ormond Street Hospital has developed guidelines for treating infantile haemangioma with propranolol.
The Great Ormond Street Hospital guidelines for propranolol treatment for infantile subglottic haemangioma include investigation, treatment and follow up. Propranolol is started at 1 mg/kg/day divided into three doses, increasing to 2 mg/kg/day one week later. On starting propranolol and when increasing the dose, the pulse rate and blood pressure must be checked every 30 minutes for the first 2 hours. Lesion response to treatment is assessed via serial endoscopy.
Recent reports of dramatic responses to oral propranolol in children with haemangioma and acute airway obstruction have led to increased use. We advocate caution, and have developed guidelines (including pre-treatment investigation and monitoring) to improve treatment safety. Propranolol may in time prove to be the best medical treatment for subglottic haemangioma, but at present is considered to be still under evaluation.
Anterior tongue reduction is indicated when macroglossia causes problems with oral hygiene, airway compromise, deglutition, articulation or orthognathic complications. Causes of macroglossia include hypothyroidism, mucopolysaccharide and lipid storage disease, lymphangioma, haemangioma, neurofibroma, and muscular macroglossia. This paper presents an 11-year experience of anterior tongue reduction at Great Ormond Street Hospital.
Retrospective study of patient medical records identified from the hospital ENT database. Anterior wedge resection was the preferred technique.
Anterior tongue reduction was performed on 18 patients, due to cystic hygroma with tongue involvement (nine patients), Beckwith–Wiedemann syndrome (eight) and Down's syndrome (one). Anterior wedge resection was preferred, using electrocautery in the majority, except for four cases involving CO2 laser. All but one patient had a good surgical outcome (i.e. tongue in mouth at rest). One patient subsequently required multiple laser procedures for recurrent macroglossia.
Anterior tongue reduction can be a safe procedure, with limited post-operative morbidity, consistently resulting in good surgical outcomes and improvement in macroglossia symptoms. Speech development does not appear to be adversely affected.
Airway compromise due to paediatric intubation injuries is well documented; however, intubation injuries may also cause severe voice disorders. We report our experience and review the world literature on the voice effects of traumatic paediatric intubation.
We report five cases of children referred to Great Ormond Street Hospital for Children who suffered traumatic avulsion of the vocal fold at the time of, or secondary to, endotracheal intubation. All children had significant dysphonia and underwent specialist voice therapy.
The mechanisms of injury, risk factors and management of the condition are discussed. Children suffering traumatic intubation require follow up throughout childhood and beyond puberty as their vocal needs and abilities change. At the time of writing, none of the reported patients had yet undergone reconstructive or medialisation surgery. However, regular specialist voice therapy evaluation is recommended for such patients, with consideration of phonosurgical techniques including injection laryngoplasty or thyroplasty.
To report the successful use of a surgical approach for the treatment of drooling in a case of oro-motor dyspraxia.
A seven-year-old girl with a diagnosis of oro-motor dyspraxia was referred for management of drooling; this was her only symptom. There were no focal neurological abnormalities. Conservative measures had not helped, and her parents were keen for definitive treatment. Bilateral submandibular duct transposition was performed with no complications. The patient's drooling improved immediately.
There are currently no reports in the literature of surgery for persistent drooling in children with oro-motor dyspraxia who are otherwise neurologically and developmentally normal. The mainstay of treatment is speech and language therapy. We report the successful use of surgical techniques, usually reserved for children with cerebral palsy or severe neurological disorders, to treat drooling in an otherwise normal seven-year-old child with oro-motor dyspraxia.
Multiple surgical procedures have been advocated for the management of problematic drooling in neurologically impaired children. Parotid duct ligation is a quick and simple operation conducted via an intra-oral approach and usually performed simultaneously with other procedures. In this study, we aimed to evaluate the effectiveness of parotid duct ligation as a discrete procedure.
All children who underwent bilateral parotid duct ligation as the solitary operative intervention at that time, between February 2003 and September 2006, were included in the study.
Ten children were studied. Surgery was successful in 80 per cent of cases. One patient (10 per cent) had a post-operative wound infection.
Bilateral parotid duct ligation is an effective yet conservative operation for drooling in neurologically impaired children. It requires minimal surgical dissection and has a low morbidity rate. It should be considered as a potential first-line procedure in children who aspirate, and as a further surgical option in anterior droolers or those who continue to drool unacceptably following prior surgical intervention.
Embryological remnants of third or fourth branchial pouches are a rare but important cause of recurrent neck abscesses in children. They are characterised by an internal opening in the piriform fossa. Traditional management involves surgical excision of the entire tract. We present our experience with the use of monopolar diathermy applied to the internal sinus opening as a treatment modality for this condition.
Materials and methods:
A retrospective, case report review was performed.
Four cases of piriform fossa sinus were treated with monopolar diathermy to the sinus opening via an endoscopic approach. The first three cases were treated in this way for recurrence, following external tract excision, while the fourth case had simultaneous excision of the tract and diathermy to the piriform fossa opening. There were no serious complications and no recurrence within a follow-up period ranging from nine to 27 months.
Obliteration of the internal opening of these sinuses by endoscopic diathermy is a safe and effective management option for this condition, either as an alternative to or as an adjunct to external surgical excision of the tract.
We report a rare case of chronic facial pain following sclerotherapy for intraparotid haemolymphangioma, thereby highlighting an important clinical consideration when advising this treatment option as an alternative to surgery in the head and neck.
Case report, with a review of relevant literature.
Sclerotherapy of lymphangiomata is well reported in the literature. Unusually, our young patient with an intraparotid haemolymphangioma experienced severe, chronic pain following intralesional injection of sodium tetradecyl sulphate, which required management by a specialist pain service. We discuss the technique of sclerotherapy for such lesions, and also discuss the potential side effects of two agents commonly used in our centre: OK 432 and sodium tetradecyl sulphate.
Non-surgical treatments of lymphangiomata and venous vascular malformations are not without complication. Both patient and clinician should be aware of this, and of the other potential side effects of sclerotherapy, prior to its use in the head and neck.
Objective: To assess whether lateral semicircular canal (LSCC) ossification is more advanced than that in the cochlear basal turn, in order to judge the value of the former as a predictor.
Methods: Retrospective review of 33 paediatric patients from our cochlear implant programme, with profound sensorineural hearing loss after bacterial meningitis. Magnetic resonance imaging (MRI), computed tomography (CT) scans and operative findings were reviewed.
Results: On CT, LSCC ossification scores were more advanced than those for the cochlear basal turn in 69.9 per cent of implanted ears. Forty-five per cent (15/33) of children had ossification at surgery. In predicting this, the sensitivity of CT LSCC ossification was 90 per cent and that of MRI LSCC ossification was 83.3 per cent.
Conclusions: The more advanced ossification found in the LSCC, compared with that in the cochlear basal turn, adds to previous findings of LSCC pathology predicting cochlear ossification. Surprisingly, CT of the LSCC appears to be no less valuable than MRI in pre-operative cochlear implant assessment of post-meningitic children.
Subglottic haemangioma is a potentially life-threatening condition for which various treatment modalities are available. The objective of this study was to evaluate our results for open excision of subglottic haemangioma. The study assessed 18 patients who had been treated at a paediatric tertiary referral centre. Most of these patients (83.3 per cent) had undergone open surgical excision without post-operative tracheostomy and had been intubated for several days post-operatively (single-stage procedure). In most of these patients (66.7 per cent), an anterior cartilage graft had been used for reconstruction. The average follow up in this study was 25 months. All the patients in this series had achieved an adequate airway after the procedure. One patient had developed a recurrence of haemangioma in the trachea at a later date. The results of open surgical excision in this study were very encouraging. Seventeen out of 18 (94.4 per cent) patients had avoided tracheostomy or had been decannulated as a direct result of surgery. One of these 18 patients (5.6 per cent) had required a temporary post-operative tracheostomy for 13 months as the subglottis cleared; this was classed as a partial success. Our experience is that open excision is a highly successful ‘one stop’ treatment for subglottic haemangioma, which avoids prolonged use of steroids and multiple endoscopic procedures. No patient in this series developed subglottic stenosis, which can be a significant complication of laser application.
A case is presented of a nine-month-old male infant who presented acutely with an anterior neck and mediastinum mass compressing the trachea. Radiological assessment by ultrasound, magnetic resonance imaging and computed tomography suggested the nature of the mass to be a lymphatic malformation (cystic hygroma). The excised specimen was revealed as a mature teratoma. The inability to distinguish between lymphatic malformation and teratoma on multi-imaging modalities confers a risk of mismanaging these lesions with the use of sclerotherapy; surgical excision is the necessary treatment. The potential consequences are discussed.
The base case model, discussed in chapter 11, assumed uniform rates of return across countries but allowed for different rates of return on different categories of investment. Specifically, we assumed that pipeline investments were least risky, followed by LNG regasification and liquefaction terminals, and then by mining projects (or exploration and development). The risk associated with pipeline investment is low as regulation often keeps the costs associated with transporting gas via pipeline quite stable. By contrast, since LNG liquefaction and regasification terminals embody less mature technologies, their costs of construction are likely to be more variable. Some of the risks associated with LNG, however, may be ameliorated by “bankable” contracts for LNG sales that limit variability in returns. The resource-mining projects are most risky because there is substantial geological uncertainty (such as initial reserve assessment, ultimate recoverability, and so forth), as well as economic uncertainty resulting from variation in commodity prices.
Assuming that rates of return on a given category of investment are uniform across countries ignores political factors that can greatly affect the risks of investing in different countries. These differing risks are a major reason that resources in some countries remain undeveloped. The relatively small amount of capital currently invested in such countries should make the return to capital relatively large and attract new investments, but the political risks may more than offset the higher expected return.