Orotracheal intubation in infants performed with a stylet versus without a stylet

Background: Neonatal endotracheal intubation is a common and potentially life-saving intervention. It is a mandatory skill for neonatal trainees, but one that is difficult to master and maintain. Intubation opportunities for trainees are decreasing and success rates are subsequently falling. Use of a stylet may aid intubation and improve success. However, the potential for associated harm must be considered. Objectives To compare the benefits and harms of neonatal orotracheal intubation with a stylet versus neonatal orotracheal intubation without a stylet. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE; Embase; the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and previous reviews. We also searched cross-references, contacted expert informants, handsearched journals, and looked at conference proceedings. We searched clinical trials registries for current and recently completed trials. We conducted our most recent search in April 2017. Selection criteria All randomised, quasi–randomised, and cluster-randomised controlled trials comparing use versus non-use of a stylet in neonatal orotracheal intubation. Data collection and analysis: Two review authors independently assessed results of searches against predetermined criteria for inclusion, assessed risk of bias, and extracted data. We used the standard methods of the Cochrane Collaboration, as documented in the Cochrane Handbook for Systemic Reviews of Interventions, and of the Cochrane Neonatal Review Group. Main results: We included a single-centre non-blinded randomised controlled trial that reported a total of 302 intubation attempts in 232 infants. The median gestational age of enrolled infants was 29 weeks. Paediatric residents and fellows performed the intubations. We judged the study to be at low risk of bias overall. Investigators compared success rates of first-attempt intubation with and without use of a stylet and reported success rates as similar between stylet and no-stylet groups (57% and 53%) (P = 0.47). Success rates did not differ between groups in subgroup analyses by provider level of training and infant weight. Results showed no differences in secondary review outcomes, including duration of intubation, number of attempts, participant instability during the procedure, and local airway trauma. Only 25% of all intubations took less than 30 seconds to perform. Study authors did not report neonatal morbidity nor mortality. We considered the quality of evidence as low on GRADE analysis, given that we identified only one unblinded study. Authors' conclusions: Current available evidence suggests that use of a stylet during neonatal orotracheal intubation does not significantly improve the success rate among paediatric trainees. However, only one brand of stylet and one brand of endotracheal tube have been tested, and researchers performed all intubations on infants in a hospital setting. Therefore, our results cannot be generalised beyond these limitations

Quantum-accelerated constraint programming

Constraint programming (CP) is a paradigm used to model and solve constraint satisfaction and combinatorial optimization problems. In CP, problems are modeled with constraints that describe acceptable solutions and solved with backtracking tree search augmented with logical inference. In this paper, we show how quantum algorithms can accelerate CP, at both the levels of inference and search. Leveraging existing quantum algorithms, we introduce a quantum-accelerated filtering algorithm for the $\texttt{alldifferent}$ global constraint and discuss its applicability to a broader family of global constraints with similar structure. We propose frameworks for the integration of quantum filtering algorithms within both classical and quantum backtracking search schemes, including a novel hybrid classical-quantum backtracking search method. This work suggests that CP is a promising candidate application for early fault-tolerant quantum computers and beyond.Comment: published in Quantu

Study of the inner dust envelope and stellar photosphere of the AGB star R Doradus using SPHERE/ZIMPOL

We use high-angular-resolution images obtained with SPHERE/ZIMPOL to study the photosphere, the warm molecular layer, and the inner wind of the close-by oxygen-rich AGB star R Doradus. We present observations in filters V, cntH$\alpha$, and cnt820 and investigate the surface brightness distribution of the star and of the polarised light produced in the inner envelope. Thanks to second-epoch observations in cntH$\alpha$, we are able to see variability on the stellar photosphere. We find that in the first epoch the surface brightness of R Dor is asymmetric in V and cntH$\alpha$, the filters where molecular opacity is stronger, while in cnt820 the surface brightness is closer to being axisymmetric. The second-epoch observations in cntH$\alpha$ show that the morphology of R Dor changes completely in a timespan of 48 days to a more axisymmetric and compact configuration. The polarised intensity is asymmetric in all epochs and varies by between a factor of 2.3 and 3.7 with azimuth for the different images. We fit the radial profile of the polarised intensity using a spherically symmetric model and a parametric description of the dust density profile, $\rho(r)=\rho_\circ r^{-n}$. On average, we find exponents of $- 4.5 \pm 0.5$ that correspond to a much steeper density profile than that of a wind expanding at constant velocity. The dust densities we derive imply an upper limit for the dust-to-gas ratio of $\sim 2\times10^{-4}$ at 5.0 $R_\star$. Given the uncertainties in observations and models, this value is consistent with the minimum values required by wind-driving models for the onset of a wind, of $\sim 3.3\times10^{-4}$. However, if the steep density profile we find extends to larger distances from the star, the dust-to-gas ratio will quickly become too small for the wind of R Dor to be driven by the grains that produce the scattered light.Comment: 10 pages, 8 figures, 4 table

Self-Pulsating Semiconductor Lasers: Theory and Experiment

We report detailed measurements of the pump-current dependency of the self-pulsating frequency of semiconductor CD lasers. A distinct kink in this dependence is found and explained using rate-equation model. The kink denotes a transition between a region where the self-pulsations are weakly sustained relaxation oscillations and a region where Q-switching takes place. Simulations show that spontaneous emission noise plays a crucial role for the cross-over.Comment: Revtex, 16 pages, 7 figure

Parental Emotional Support as a Driver of Next Generations' Family Business Succession Intentions

Parents play an important role in shaping the career intentions of their offspring. Building on social cognitive theory, we explore how cognitive factors mediate the relationship between parental emotional support and family business succession intentions. To test our hypotheses, we draw on a sample of 21,984 students from a family business background across 41 countries, derived from the 2018 Global University Entrepreneurial Spirit Students’ Survey (GUESSS). We find that parental emotional support directly influences succession intentions, and that this relationship is mediated by the next generation’s entrepreneurial self-efficacy and their affective commitment to the family business. We also find a moderating effect of birth order, with lower direct effects on succession intentions for children with older siblings. Lastly, we report a gender effect, finding that emotional support has a stronger influence among males. In addition, we contribute to a greater understanding of the nuances of next-generation succession intentions and parental influence for male and female successors

Exploring Pompeii: discovering hospitality through research synergy

Hospitality research continues to broaden through an ever-increasing dialogue and alignment with a greater number of academic disciplines. This paper demonstrates how an enhanced understanding of hospitality can be achieved through synergy between archaeology, the classics and sociology. It focuses on classical Roman life, in particular Pompeii, to illustrate the potential for research synergy and collaboration, to advance the debate on hospitality research and to encourage divergence in research approaches. It demonstrates evidence of commercial hospitality activities through the excavation hotels, bars and taverns, restaurants and fast food sites. The paper also provides an example of the benefits to be gained from multidisciplinary analysis of hospitality and tourism

Applying machine learning to improve simulations of a chaotic dynamical system using empirical error correction

Dynamical weather and climate prediction models underpin many studies of the Earth system and hold the promise of being able to make robust projections of future climate change based on physical laws. However, simulations from these models still show many differences compared with observations. Machine learning has been applied to solve certain prediction problems with great success, and recently it's been proposed that this could replace the role of physically-derived dynamical weather and climate models to give better quality simulations. Here, instead, a framework using machine learning together with physically-derived models is tested, in which it is learnt how to correct the errors of the latter from timestep to timestep. This maintains the physical understanding built into the models, whilst allowing performance improvements, and also requires much simpler algorithms and less training data. This is tested in the context of simulating the chaotic Lorenz '96 system, and it is shown that the approach yields models that are stable and that give both improved skill in initialised predictions and better long-term climate statistics. Improvements in long-term statistics are smaller than for single time-step tendencies, however, indicating that it would be valuable to develop methods that target improvements on longer time scales. Future strategies for the development of this approach and possible applications to making progress on important scientific problems are discussed.Comment: 26p, 7 figures To be published in Journal of Advances in Modeling Earth System