Outcomes of Childhood Asthma and Wheezy Bronchitis. A 50-Year Cohort Study

Rationale: Cohort studies suggest that airflow obstruction is established early in life, manifests as childhood asthma and wheezy bronchitis, and continues into early adulthood. Although an association between childhood asthma and chronic obstructive pulmonary disease (COPD) in later life has been demonstrated, it is unclear if childhood wheezy bronchitis is associated with COPD. Objectives: To investigate whether childhood wheezy bronchitis increases the risk of COPD in the seventh decade. Methods: A cohort of children recruited in 1964 at age 10 to 15 years, which was followed up in 1989, 1995, and 2001, was followed up again in 2014 when at age 60 to 65 years. Discrete time-to-event and linear mixed effects models were used. Measurements and Main Results: FEV1 and FVC were measured. COPD was defined as post-bronchodilator FEV1/FVC <0.7. Childhood wheezing phenotype was related to 1989, 1995, 2001, and 2014 spirometry data. Three hundred thirty subjects, mean age 61 years, were followed up: 38 with childhood asthma; 53 with childhood wheezy bronchitis; and 239 control subjects (of whom 57 developed adulthood-onset wheeze between ages 16 and 46 yr). In adjusted multivariate analyses, childhood asthma was associated with an increased risk of COPD (odds ratio, 6.37; 95% confidence interval, 3.73–10.94), as was childhood wheezy bronchitis (odd ratio 1.81; 95% confidence interval, 1.12–2.91). The COPD risk increased with childhood asthma, and wheezy bronchitis was associated with reduced FEV1 that was evident by the fifth decade and not an accelerated rate of FEV1 decline. In contrast, adulthood-onset wheeze was associated with accelerated FEV1 decline. Conclusions: Childhood wheezy bronchitis and asthma are associated with an increased risk of COPD and reduced ventilatory function

A possible method for non-Hermitian and non-PTPT-symmetric Hamiltonian systems

A possible method to investigate non-Hermitian Hamiltonians is suggested through finding a Hermitian operator $\eta_+$ and defining the annihilation and creation operators to be $\eta_+$-pseudo-Hermitian adjoint to each other. The operator $\eta_+$ represents the $\eta_+$-pseudo-Hermiticity of Hamiltonians. As an example, a non-Hermitian and non-$PT$-symmetric Hamiltonian with imaginary linear coordinate and linear momentum terms is constructed and analyzed in detail. The operator $\eta_+$ is found, based on which, a real spectrum and a positive-definite inner product, together with the probability explanation of wave functions, the orthogonality of eigenstates, and the unitarity of time evolution, are obtained for the non-Hermitian and non-$PT$-symmetric Hamiltonian. Moreover, this Hamiltonian turns out to be coupled when it is extended to the canonical noncommutative space with noncommutative spatial coordinate operators and noncommutative momentum operators as well. Our method is applicable to the coupled Hamiltonian. Then the first and second order noncommutative corrections of energy levels are calculated, and in particular the reality of energy spectra, the positive-definiteness of inner products, and the related properties (the probability explanation of wave functions, the orthogonality of eigenstates, and the unitarity of time evolution) are found not to be altered by the noncommutativity.Comment: 15 pages, no figures; v2: clarifications added; v3: 16 pages, 1 figure, clarifications made clearer; v4: 19 pages, the main context is completely rewritten; v5: 25 pages, title slightly changed, clarifications added, the final version to appear in PLOS ON

Synthetic CO, H2 and H I surveys of the second galactic quadrant, and the properties of molecular gas

articleWe present CO, H2, H I and HISA (H I self-absorption) distributions from a set of simulations of grand design spirals including stellar feedback, self-gravity, heating and cooling. We replicate the emission of the second galactic quadrant by placing the observer inside the modelled galaxies and post-process the simulations using a radiative transfer code, so as to create synthetic observations. We compare the synthetic data cubes to observations of the second quadrant of the Milky Way to test the ability of the current models to reproduce the basic chemistry of the Galactic interstellar medium (ISM), as well as to test how sensitive such galaxy models are to different recipes of chemistry and/or feedback. We find that models which include feedback and self-gravity can reproduce the production of CO with respect to H2 as observed in our Galaxy, as well as the distribution of the material perpendicular to the Galactic plane. While changes in the chemistry/feedback recipes do not have a huge impact on the statistical properties of the chemistry in the simulated galaxies, we find that the inclusion of both feedback and self-gravity are crucial ingredients, as our test without feedback failed to reproduce all of the observables. Finally, even though the transition from H2 to CO seems to be robust, we find that all models seem to underproduce molecular gas, and have a lower molecular to atomic gas fraction than is observed. Nevertheless, our fiducial model with feedback and self-gravity has shown to be robust in reproducing the statistical properties of the basic molecular gas components of the ISM in our Galaxy.We thank the referee, Ralf Klessen, for his comments that helped strengthen the paper. ADC and CLD acknowledge funding from the European Research Council for the FP7 ERC starting grant project LOCALSTAR. The calculations for this paper were performed on the DiRAC Complexity machine, jointly funded by STFC and the Large Facilities Capital Fund of BIS, and the University of Exeter Supercomputer, a DiRAC Facility jointly funded by STFC, the Large Facilities Capital Fund of BIS and the University of Exeter. Fig. 1 was produced using SPLASH (Price 2007). We acknowledge the use of NASA’s SkyView facility (http://skyview.gsfc.nasa.gov) located at NASA Goddard Space Flight Center. We also thank A. Rodrigues for providing high-resolution dust column density maps for benchmarking

The group structure of non-Abelian NS-NS transformations

We study the transformations of the worldvolume fields of a system of multiple coinciding D-branes under gauge transformations of the supergravity Kalb-Ramond field. We find that the pure gauge part of these NS-NS transformations can be written as a U(N) symmetry of the underlying Yang-Mills group, but that in general the full NS-NS variations get mixed up non-trivially with the U(N). We compute the commutation relations and the Jacobi identities of the bigger group formed by the NS-NS and U(N) transformations.Comment: Latex, 11 pages. v2: Typos corrected; version to appear in JHEP

Innovative learning at The University of Edinburgh

The activities available to civil engineering students during the University of Edinburgh's innovative learning week in 2012 were examined. The academic staff proposed a wide range of possible activities and student participation was optional. Popular activities were those with a ‘hands-on’ element: making or doing something. The practical activities offered included designing and building trebuchets, relaying railway permanent way on a heritage railway, practical workshops on engineering in international development and learning to juggle. These activities suggested that heuristic learning by trial and error was likely to enhance the visualisation skills that contribute to good engineering design. Further, the linking of achievement to purposeful practice rather than innate talent could inform teaching methods in the future. They also showed that in some cases safety culture messages were still not fully assimilated by students

Tuberculosis incidence correlates with sunshine : an ecological 28-year time series study

Birmingham is the largest UK city after London, and central Birmingham has an annual tuberculosis incidence of 80 per 100,000. We examined seasonality and sunlight as drivers of tuberculosis incidence. Hours of sunshine are seasonal, sunshine exposure is necessary for the production of vitamin D by the body and vitamin D plays a role in the host response to tuberculosis. Methods: We performed an ecological study that examined tuberculosis incidence in Birmingham from Dec 1981 to Nov 2009, using publicly-available data from statutory tuberculosis notifications, and related this to the seasons and hours of sunshine (UK Meteorological Office data) using unmeasured component models. Results: There were 9,739 tuberculosis cases over the study period. There was strong evidence for seasonality, with notifications being 24.1% higher in summer than winter (p<0.001). Winter dips in sunshine correlated with peaks in tuberculosis incidence six months later (4.7% increase in incidence for each 100 hours decrease in sunshine, p<0.001). Discussion and Conclusion: A potential mechanism for these associations includes decreased vitamin D levels with consequent impaired host defence arising from reduced sunshine exposure in winter. This is the longest time series of any published study and our use of statutory notifications means this data is essentially complete. We cannot, however, exclude the possibility that another factor closely correlated with the seasons, other than sunshine, is responsible. Furthermore, exposure to sunlight depends not only on total hours of sunshine but also on multiple individual factors. Our results should therefore be considered hypothesis-generating. Confirmation of a potential causal relationship between winter vitamin D deficiency and summer peaks in tuberculosis incidence would require a randomized-controlled trial of the effect of vitamin D supplementation on future tuberculosis incidence

U-dual fluxes and Generalized Geometry

We perform a systematic analysis of generic string flux compactifications, making use of Exceptional Generalized Geometry (EGG) as an organizing principle. In particular, we establish the precise map between fluxes, gaugings of maximal 4d supergravity and EGG, identifying the complete set of gaugings that admit an uplift to 10d heterotic or type IIB supegravity backgrounds. Our results reveal a rich structure, involving new deformations of 10d supergravity backgrounds, such as the RR counterparts of the $\beta$-deformation. These new deformations are expected to provide the natural extension of the $\beta$-deformation to full-fledged F-theory backgrounds. Our analysis also provides some clues on the 10d origin of some of the particularly less understood gaugings of 4d supergravity. Finally, we derive the explicit expression for the effective superpotential in arbitrary N = 1 heterotic or type IIB orientifold compactifications, for all the allowed fluxes.Comment: 58 pages, 6 table

Dynamic Limits on Planar Libration-Orbit Coupling Around an Oblate Primary

This paper explores the dynamic properties of the planar system of an ellipsoidal satellite in an equatorial orbit about an oblate primary. In particular, we investigate the conditions for which the satellite is bound in librational motion or when the satellite will circulate with respect to the primary. We find the existence of stable equilibrium points about which the satellite can librate, and explore both the linearized and non-linear dynamics around these points. Absolute bounds are placed on the phase space of the libration-orbit coupling through the use of zero-velocity curves that exist in the system. These zero-velocity curves are used to derive a sufficient condition for when the satellite's libration is bound to less than 90 degrees. When this condition is not satisfied so that circulation of the satellite is possible, the initial conditions at zero libration angle are determined which lead to circulation of the satellite. Exact analytical conditions for circulation and the maximum libration angle are derived for the case of a small satellite in orbits of any eccentricity.Comment: Submitted to Celestial Mechanics and Dynamical Astronom

An inhibitory pull-push circuit in frontal cortex.

Push-pull is a canonical computation of excitatory cortical circuits. By contrast, we identify a pull-push inhibitory circuit in frontal cortex that originates in vasoactive intestinal polypeptide (VIP)-expressing interneurons. During arousal, VIP cells rapidly and directly inhibit pyramidal neurons; VIP cells also indirectly excite these pyramidal neurons via parallel disinhibition. Thus, arousal exerts a feedback pull-push influence on excitatory neurons-an inversion of the canonical push-pull of feedforward input

Palpitations following regular ibuprofen dosing in a 13-year-old girl: a case report

Abstract Introduction The sensation of palpitations may either be the initial or the only symptom of cardiac arrhythmia. We describe a case of an apparent clear temporal relationship between standard ibuprofen dosing and palpitations. A review of the medical literature revealed this to be, to the best of our knowledge, the first reported case of this type. Case presentation A 13-year-old Caucasian girl initially presented to our clinic with hamstring tendinitis. She was commenced on a medication regimen of paracetamol and ibuprofen. After the third ibuprofen dose, she experienced palpitations. These were associated with lower chest and/or upper abdominal discomfort, and a feeling of being hot and sweaty. Her symptoms ceased upon the cessation of ibuprofen therapy. Conclusion Cardiac arrhythmia is a potentially fatal disorder that may exhibit heart palpitations as its initial (or only) symptom. The prompt recognition of the cause of the symptom can reduce mortality and morbidity associated with any underlying pathological processes. There is a need to investigate cases of recurrent palpitations so as to exclude underlying structural cardiac pathology and/or abnormal cardiac rhythm.</p