Estimation of vortex density after superconducting film quench

This paper addresses the problem of vortex formation during a rapid quench in a superconducting film. It builds on previous work showing that in a local gauge theory there are two distinct mechanisms of defect formation, based on fluctuations of the scalar and gauge fields, respectively. We show how vortex formation in a thin film differs from the fully two-dimensional case, on which most theoretical studies have focused. We discuss ways of testing theoretical predictions in superconductor experiments and analyse the results of recent experiments in this light.Comment: 7 pages, no figure

A single-center, observational study of 607 children & young people presenting with Differences in Sex Development (DSD)

Context Differences in sex development (DSD) represent a wide range of conditions presenting at different ages to various health professionals. Establishing a diagnosis, supporting the family and developing a management plan are important. Objective We aimed to better understand the presentation and prevalence of pediatric DSD. Design A retrospective, observational cohort study was undertaken of all children and young people (CYP) referred to a DSD multi-disciplinary team over 25 years (1995-2019). Setting A single tertiary paediatric center. Participants In total, 607 CYP (520 regional referrals) were included. Main Outcome Measures Data were analyzed for diagnosis, sex-assignment, age and mode of presentation, additional phenotypic features, mortality, and approximate point prevalence. Results Amongst the three major DSD categories, sex chromosome DSD was diagnosed in 11.2% (68/607) (most commonly 45, X/46, XY mosaicism), 46, XY DSD in 61.1% (371/607) (multiple diagnoses often with associated features), while 46, XX DSD occurred in 27.7% (168/607) (often 21-hydroxylase deficiency). Most children (80.1%) presented as neonates, usually with atypical genitalia, adrenal insufficiency, undescended testes or herniae. Those presenting later had diverse features. Rarely, the diagnosis was made antenatally (3.8%, n = 23) or following incidental karyotyping/family history (n = 14). Mortality was surprisingly high in 46, XY children, usually due to complex associated features (46, XY girls, 8.3%; 46, XY boys, 2.7%). The approximate point prevalence of neonatal referrals for investigation of DSD was 1 in 6,347 births, and 1 in 5,101 overall throughout childhood. Conclusions DSD represent a diverse range of conditions that can present at different ages. Pathways for expert diagnosis and management are important to optimize care

Measuring Cosmic Defect Correlations in Liquid Crystals

From the theory of topological defect formation proposed for the early universe, the so called Kibble mechanism, it follows that the density correlation functions of defects and anti-defects in a given system should be completely determined in terms of a single length scale $\xi$, the relevant domain size. Thus, when lengths are expressed in units of $\xi$, these distributions should show universal behavior, depending only on the symmetry of the order parameter, and space dimensions. We have verified this prediction by analyzing the distributions of defects/anti-defects formed in the isotropic-nematic phase transition in a thin layer of nematic liquid crystals. Our experimental results confirm this prediction and are in reasonable agreement with the results of numerical simulations.Comment: 15 pages, 4 figures, minor changes, few new references adde

Emergency and perioperative management of adrenal insufficiency in children and young people: British Society for Paediatric Endocrinology and Diabetes consensus guidance

Adrenal insufficiency (AI) is characterised by lack of cortisol production from the adrenal glands. This can be a primary adrenal disorder or secondary to adrenocorticotropic hormone deficiency or suppression from exogenous glucocorticoids. Symptoms of AI in children may initially be non-specific and include growth faltering, lethargy, poor feeding, weight loss, abdominal pain, vomiting and lingering illnesses. AI is treated with replacement doses of hydrocortisone. At times of physiological stress such as illness, trauma or surgery, there is an increased requirement for exogenous glucocorticoids, which if untreated can lead to an adrenal crisis and death. There are no unified guidelines for those <18 years old in the UK, leading to substantial variation in the management of AI. This paper sets out guidance for intercurrent illness, medical, dental and surgical procedures to allow timely and appropriate recognition and treatment of AI and adrenal crisis for children and young people

An increase in the prevalence of type 1 and 2 diabetes in children and adolescents: Results from prescription data from a UK general practice database

AIMS: Despite evidence of an increase in the incidence of both type 1 and type 2 diabetes in youths, there are few data on the prevalence of either type in children and adolescents. The aim of this study was to investigate the prevalence of childhood diabetes over an 8-year period in the UK. METHODS: This was a retrospective cohort study that covered 8 years (January 1998 to December 2005) of UK IMS Disease Analyzer (IMS DA) data. The cohort comprised all children and adolescents aged 0–18 years who received at least one antidiabetic drug prescription during the study period. The prevalence of antidiabetic drug prescribing was used as a proxy for diabetes itself. RESULTS: Data were available on 505 754 children aged 0–18 years and a total of 37 225 antidiabetic prescriptions were issued. Insulin use increased significantly from 1.08 per 1000 children [95% confidence interval (CI) 0.96, 1.20] in 1998 to 1.98 (95% CI 1.80, 2.10) in 2005 (P < 0.001), more markedly in those aged 12 and 18 years. The use of oral antidiabetic drugs for diabetes treatment rose significantly from 0.006 per 1000 children in 1998 (95% CI 0.0043, 0.017) to 0.05 (95% CI 0.025, 0.080) (P < 0.001) in 2005. CONCLUSIONS: This study indicates a significant increase in prevalence on both type 1 and type 2 diabetes treatment in children and adolescents in the UK. Thus, this supporting evidence from other sources that the prevalence of childhood diabetes is rising rapidly. Further epidemiological studies are required to investigate the aetiology and risk factors

Rate of change (modulation) of serum growth hormone concentrations is a more important factor in determining growth rate than duration of exposure.

OBJECTIVE: To determine whether duration of exposure to GH and/or rate of change of serum GH concentration are important factors in determining the growth rate of short children. DESIGN: An analysis of parameters of occupancy percentage and rate of change of serum GH concentration was performed as part of a prospective study investigating the relationship between growth and GH in childhood. PATIENTS: Sixty-four short prepubertal children (48 male, 16 female) aged between 4.7 and 11.9 years were studied. Thirty-one children were growing with a height velocity standard deviation score between 0 and -0.8 and were defined as short normal. Thirty-three children were growing with a height velocity standard deviation score less than -0.8 and were defined as short slowly growing. MEASUREMENTS: Twenty-four hour serum GH concentration profiles were constructed by withdrawing samples at 20-minute intervals. Analysis of occupancy percentage was performed on each data array by determining cumulative distributions and plotting these as linear probits against log serum GH concentration. Estimates of peak (OC95), intermediate (OC50) and trough (OC5) occupancies were calculated. A first-order derivative of the concentration-time data array was determined for each profile as a measure of rate changes. RESULTS: First-order derivative values were significantly greater in the short normal group than in the short slowly growing children (short normal median 1.41 mU/l/min; short slowly growing median 0.72 mU/l/min; P less than 0.001). OC95 values were significantly higher in the short normal group (median 19.31 mU/l) than the short slowly growing group (median 7.69 mU/l) (P less than 0.001). There was no difference in OC50 values. OC5 values were lower in short normal children (median 0.20 mU/l) than in the short slowly growing children (0.55 mU/l) (P less than 0.003). The most important factor in determining growth rate was the rate of change in serum GH concentration (FOD). Occupancy percentage played no part in the relationship. The regression equation was Height velocity SDS = 1.16 (In FOD) - 1.03; r = 0.75; P less than 0.001 CONCLUSIONS: These data suggest that the pattern of presentation of GH in the circulation is an important factor in determining target organ response. Although occupancy percentages at differing serum GH concentrations differ between short slowly growing and short normal children, it is the rate of change of the hormone in the circulation which appears to be the more important 'signal' in terms of modulating growth