Reduction in the use of diagnostic tests in infants with risk factors for early-onset neonatal sepsis does not delay antibiotic treatment.

Despite a low positive predictive value, diagnostic tests such as complete blood count (CBC) and C-reactive protein (CRP) are commonly used to evaluate whether infants with risk factors for early-onset neonatal sepsis (EOS) should be treated with antibiotics. We investigated the impact of implementing a protocol aiming at reducing the number of diagnostic tests in infants with risk factors for EOS in order to compare the diagnostic performance of repeated clinical examination with CBC and CRP measurement. The primary outcome was the time between birth and the first dose of antibiotics in infants treated for suspected EOS. Among the 11,503 infants born at ≥35 weeks during the study period, 222 were treated with antibiotics for suspected EOS. The proportion of infants receiving antibiotics for suspected EOS was 2.1% and 1.7% before and after the change of protocol (p = 0.09). Reduction of diagnostic tests was associated with earlier antibiotic treatment in infants treated for suspected EOS (hazard ratio 1.58; 95% confidence interval [CI] 1.20-2.07; p <0.001), and in infants with neonatal infection (hazard ratio 2.20; 95% CI 1.19-4.06; p = 0.01). There was no difference in the duration of hospital stay nor in the proportion of infants requiring respiratory or cardiovascular support before and after the change of protocol. Reduction of diagnostic tests such as CBC and CRP does not delay initiation of antibiotic treatment in infants with suspected EOS. The importance of clinical examination in infants with risk factors for EOS should be emphasised

Quantum Chaos in the Bose-Hubbard model

We present a numerical study of the spectral properties of the 1D Bose-Hubbard model. Unlike the 1D Hubbard model for fermions, this system is found to be non-integrable, and exhibits Wigner-Dyson spectral statistics under suitable conditions.Comment: 4 pages, 4 figure

Factors associated with postmenstrual age at full oral feeding in very preterm infants.

We aimed to identify variables associated with gestational age at full oral feeding in a cohort of very preterm infants. In this retrospective study, all infants born below 32 weeks of gestation and admitted to a level III neonatal unit in 2015 were included. We dichotomized our population of 122 infants through the median age at full oral feeding, and explored which variables were statistically different between the two groups. We then used linear regression analysis to study the association between variables known from the literature and variables we had identified and age at full oral feeding. The median postnatal age at full oral feeding was 36 6/7weeks post menstrual age (Q1-Q3 35 6/7-392/7), and was associated with the duration of hospital of stay. In the univariable linear regression, the variables significantly associated with full oral feeding were gestational age, socioeconomic status, sepsis, patent ductus arteriosus, duration of supplementary oxygen, of non-invasive and invasive ventilation, and bronchopulmonary dysplasia. In the multivariable regression analysis, duration of non-invasive ventilation and oxygen therapy, bronchopulmonary dysplasia, and patent ductus arteriosus were associated with an older age at full oral feeding, with bronchopulmonary dysplasia the single most potent predictor. Lung disease severity is a major determinant of age at full oral feeding and thus length of stay in this population. Other factors associated with FOF include socioeconomic status and patent ductus arteriosus, There is a need for research addressing evidence-based bundles of care for these infants at risk of long-lasting feeding and neurodevelopmental impairments

Infinitesimal and local convexity of a hypersurface in a semi-Riemannian manifold

Given a Riemannian manifold M and a hypersurface H in M, it is well known that infinitesimal convexity on a neighborhood of a point in H implies local convexity. We show in this note that the same result holds in a semi-Riemannian manifold. We make some remarks for the case when only timelike, null or spacelike geodesics are involved. The notion of geometric convexity is also reviewed and some applications to geodesic connectedness of an open subset of a Lorentzian manifold are given.Comment: 14 pages, AMSLaTex, 2 figures. v2: typos fixed, added one reference and several comments, statement of last proposition correcte