A Bivariate Time Series Approach to Anthropogenic Trend Detection in Hemispheric Mean Temperatures

A bivariate time series regression approach is used to model observed variations in hemispheric mean temperature over the period 1900-96. The regression equations include deterministic predictor variables and lagged values of the two predictands, and two different forms of this basic structure are employed. The deterministic predictors considered are simple linear trends, various climate model-generated time series based on different combinations of greenhouse gas, sulfate aerosol, and solar forcing, and the Southern Oscillation index (SOI). With linear trends as the only predictors, the best model is a fourth-order bivariate autoregressive model including lagged Southern Hemisphere (SH) to Northern Hemisphere (NH) dependence, as in previous work by Kaufmann and Stern. The estimated NH and SH trends are both + 0.67°C century-1, and both are highly statistically significant. If SOI is included as an additional predictor, however, a first-order time series model, with no SH to NH dependence, is an adequate fit to the data. This shows that SOI may be an important covariate in this kind of analysis. Further analysis uses climate model-generated forcing terms representing greenhouses gases, sulfate aerosols, and solar effects, as well as SOI. The statistical analysis makes extensive use of Bayes factors as a device for discriminating among a wide spectrum of possible models. The best fits to the data are obtained when all three forcing terms are included. Total sulfate aerosol forcing of 1.1 W m-2(with a corresponding climate sensitivity of ΔT2+ = 4.2cC) is preferred to -0.7 W m-2(with sensitivity of 2.3°C), but the Bayes factor discrimination between these cases is weak

Chorion Structure of Diapause and Subitaneous Eggs of Four Diaptomid Copepods (Calanoida, Diaptomidae): SEM Observations

Scanning electron microscopic examination of diapause eggs of freshwater Ñalanoida Hemidiaptomus amblyodon Marenzeller, Eudiaptomus vulgaris (Schmeil), Å. graciloides (Lilljeborg) and subitaneous one s of E. gracilis (Sars) is described. The chorion surface ornamentation and number of coated layers are revealed. Diapause eggs have a thick (0.6–4.8 μ), at least two-layered chorion with patterned surface, whereas subitaneous eggs have a thin (0.13–0.25 μ), single-layered chorion with smooth surface. The mean number of eggs in egg sac, diameter of eggs and thickness of chorion were measured. The significance of the egg chorion thickness for diaptomid species inhabited temporary and/or permanent water-bodies is discussed.Сканирующая электронная микроскопия яиц пресноводных каланоид Hemidiaptomus amblyodon Marenzeller, Eudiaptomus vulgaris (Schmeil), Е. graciloides (Lilljeborg) и E. gracilis (Sars) дала возможность показать особенности покровов и количество оболочек у диапаузирующих и субитанных яиц этих видов. Диапаузирующие яйца имеют толстую (0,6–4,8 мкм), двухслойную оболочку с орнаментом на поверхностном слое, в то время как субитанные яйца имеют тонкую (0,13–0,25 мкм), однослойную оболочку c гладким поверхностным слоем. Среднее количество яиц в яйцевом мешке, диаметр яиц и толщина хориона указаны. Обсуждается значение толщины оболочки яиц в связи с обитанием диаптомид во временных и постоянных водоемах

Optical response of two-dimensional electron fluids beyond the Kohn regime: strong non-parabolic confinement and intense laser light

We investigate the linear and non-linear optical response of two-dimensional (2D) interacting electron fluids confined by a strong non-parabolic potential. We show that such fluids may exhibit higher-harmonic spectra under realistic experimental conditions. Higher harmonics arise as the electrons explore anharmonicities of the confinement potential (electron-electron interactions reduce this non-linear effect). This opens the possibility of controlling the optical functionality of such systems by engineering the confinement potential. Our results were obtained within time-dependent density-functional theory, employing the adiabatic local-density approximation. A classical hydrodynamical model is in good agreement with the quantum-mechanical results.Comment: 4 pages, 4 figure

The other side of the story - maternal perceptions of safety advice and information: a qualitative approach

Background: A qualitative study of maternal perceptions of home safety advice. The aim was to gain an understanding of maternal perceptions of and possible barriers to the implementation of home safety advice. Methods: Semi-structured interviews with 37 mothers with a child aged less than 5 years of age; 16 were mothers living in an area of socio-economic disadvantage (with a high rate of childhood unintentional injury), 21 were mothers living in an area of relative affluence (with a low rate of childhood unintentional injury). Thematic analysis was used to analyse the data. Results: Although some mothers living in both areas found talking to a health professional about child home safety was helpful, mothers in both areas tended to find talking to other mothers as being more helpful and they preferred this to talking to a professional. Barriers to obtaining safety advice from professionals exist for mothers living in both areas. Mothers living in the advantaged area describe ‘feeling silly’ and that they should ‘know it already’ when talking to professionals. Mothers living in the disadvantaged area are less likely to access home safety advice due to fear of being perceived as an incompetent mother and the fear of social service involvement. Conclusions: Mothers find home safety advice from other parents more useful and prefer this to advice from professionals. This suggests greater use could be made of appropriately trained parents to deliver safety advice and education. Fear and mistrust can limit access to child safety advice in parents living in disadvantaged areas and this may be a potential explanation for differential unintentional injury rates as those who need the advice and support most may be least likely to access it. Further research should explore how professionals can build trust, gain parents’ confidence and provide child safety advice and education that is targeted appropriately to parents living circumstances and their child safety needs

Potential for using simulated altitude as a means of prehabilitation:a physiology study

The current pandemic of surgical complications necessitates urgent and pragmatic innovation to reduce postoperative morbidity and mortality, which are associated with poor pre-operative fitness and anaemia. Exercise prehabilitation is a compelling strategy, but it has proven difficult to establish that it improves outcomes either in isolation or as part of a multimodal approach. Simulated altitude exposure improves performance in athletes and offers a novel potential means of improving cardiorespiratory and metabolic fitness and alleviating anaemia within the prehabilitation window. We aimed to provide an initial physiological foundation for ‘altitude prehabilitation’ by determining the physiological effects of one week of simulated altitude (FIO2 15%, equivalent to approximately 2438 m (8000 ft)) in older sedentary volunteers. The study used a randomised, double-blind, sham-controlled crossover design. Eight participants spent counterbalanced normoxic and hypoxic weeks in a residential hypoxia facility and underwent repeated cardiopulmonary exercise tests. Mean (SD) age of participants was 64 (7) y and they were unfit, with mean (SD) baseline anaerobic threshold 12 (2) ml.kg-1.min-1 and mean (SD) peak V̇O2 15 (3) ml.kg-1.min-1. Hypoxia was mild (mean (SD) SpO2 93 (2) %, p &lt; 0.001) and well-tolerated. Despite some indication of greater peak exercise capacity following hypoxia, overall there was no effect of simulated altitude on anaerobic threshold or peak V̇O2. However, hypoxia induced a substantial increase in mean (SD) haemoglobin of 1.5 (2.7) g.dl-1 (13% increase, p = 0.028). This study has established the concept and feasibility of ‘altitude prehabilitation’ and demonstrated specific potential for improving haematological fitness. Physiologically, there is value in exploring a possible role for simulated altitude in pre-operative optimisation.</p

Incidence and sociodemographic characteristics of eczema diagnosis in children: a cohort study

Letter to the Editor

Patient-reported outcome measures for acne: a mixed-methods validation study (acne PROMs).

OBJECTIVES: To examine the acceptability and validity of two patient-reported outcome measures (PROMs) for adult acne, comparing them to the validated Acne-specific Quality of Life (Acne-QoL) measure. DESIGN: Mixed-methods validation study. SETTING: Participants were recruited by (1) mail-out through primary care if they had ever consulted for acne and received a prescription for acne treatment within the last 6 months, (2) opportunistically in secondary care and (3) poster advertisement in community venues. PARTICIPANTS: 221 (204 quantitative and 17 qualitative) participants with acne, aged 18-50 years. OUTCOME MEASURES: Quantitative sub-study participants completed Acne-QoL, Skindex-16 and Comprehensive Acne Quality of Life Scale (CompAQ) at baseline, 24 hours and 6 weeks. Qualitative sub-study participants took part in cognitive think-aloud interviews, while completing the same measures. Transcribed audio recordings were analysed using inductive thematic analysis. RESULTS: Quantitative analyses suggested high internal consistency (Cronbach's alpha 0.74-0.96) and reliability (intraclass correlation coefficient values 0.88-0.97) for both questionnaires. Both scales showed floor effects on some subdomains. Skindex-16 and CompAQ showed good evidence of construct validity when compared with Acne-QoL with Spearman's correlation coefficients 0.54-0.81, and good repeatability over 24 hours.Qualitative data uncovered wide-ranging views regarding usability and acceptability. Interviewees held strong but differing views about layout, question/response wording, redundant/similar questions and guidance notes. Similarly, interviewees differed in perceptions of acceptability of the different scales, particularly on relatability of questions and emotive reactions to scales. CONCLUSIONS: All PROMs performed well in statistical analyses. No PROM showed superior usability and acceptability in the qualitative study. Any PROM should be acceptable for further research in adult acne but researchers should consider the different domains and whether they will measure only facial or facial and trunk acne before making a selection. A new PROM or further evaluation of novel PROMs may be beneficial

Universal eigenvector statistics in a quantum scattering ensemble

We calculate eigenvector statistics in an ensemble of non-Hermitian matrices describing open quantum systems [F. Haake et al., Z. Phys. B 88, 359 (1992)] in the limit of large matrix size. We show that ensemble-averaged eigenvector correlations corresponding to eigenvalues in the center of the support of the density of states in the complex plane are described by an expression recently derived for Ginibre's ensemble of random non-Hermitian matrices.Comment: 4 pages, 5 figure

A Case Series on Genotype and Outcome of Liver Transplantation in Children with Niemann-Pick Disease Type C

Background: To report on clinical presentation and outcomes of children who underwent liver transplantation (LTx) and were subsequently diagnosed to have Niemann-Pick type C (NPC). Methods: Retrospective, descriptive, multi-centre review of children diagnosed with NPC who underwent LTx (2003–2018). Diagnosis was made by filipin skin test or genetic testing. Results: Nine children were identified (six centres). Neonatal acute liver failure was the most common indication for LTx (seven children). Median age at first presentation: 7 days (range: 0–37). The most prevalent presenting symptoms: jaundice (8/9), hepatosplenomegaly (8/9) and ascites (6/9). 8/9 children had a LTx before the diagnosis of NPC. Genetic testing revealed mutations in NPC1 correlating with a severe biochemical phenotype in 5 patients. All 9 children survived beyond early infancy. Seven children are still alive (median follow-up time of 9 (range: 6–13) years). Neurological symptoms developed in 4/7 (57%) patients at median 9 (range: 5–13) years following LTx. Conclusion: Early diagnosis of NPC continues to be a challenge and a definitive diagnosis is often made only after LTx. Neurological disease is not prevented in the majority of patients. Genotype does not appear to predict neurological outcome after LTx. LTx still remains controversial in NPC