Monotonicity Results for Coherent MIMO Rician Channels

The dependence of the Gaussian input information rate on the line-of-sight (LOS) matrix in multiple-input multiple-output coherent Rician fading channels is explored. It is proved that the outage probability and the mutual information induced by a multivariate circularly symmetric Gaussian input with any covariance matrix are monotonic in the LOS matrix D, or more precisely, monotonic in D'D in the sense of the Loewner partial order. Conversely, it is also demonstrated that this ordering on the LOS matrices is a necessary condition for the uniform monotonicity over all input covariance matrices. This result is subsequently applied to prove the monotonicity of the isotropic Gaussian input information rate and channel capacity in the singular values of the LOS matrix. Extensions to multiple-access channels are also discussed.Comment: 14 pages, submitted to IEEE Transactions on Information Theor

Antenatal corticosteroids for fetal lung maturation in threatened preterm delivery: indications and administration

Introduction: Antenatal maternal administration of corticosteroids has been shown to reduce morbidity and mortality rates in preterm delivery. Threatened spontaneous or medically indicated preterm delivery for maternal or fetal indications between 24 and 34weeks of gestation with unknown fetal lung maturity status are indications for antenatal corticosteroid administration. Recent studies have challenged current practice of antenatal glucocorticoid use. The goal of this expert letter is to provide recommendations based for the clinical use of antenatal glucocorticoids based on the current evidence from published studies. Methods: The published literature (PubMed search), as well as the recommendations of other national societies, has been searched and taken into consideration for these recommendations. Results/conclusions: The standard regimen of antenatal corticosteroids involves a single course of 2×12mg betamethasone administered intramuscularly within 24h. The administration of corticosteroids usually is performed between 24 and 34weeks gestation. However, under particular circumstances it may be beneficial even at 23weeks and at 35-36weeks of gestation. The evidence to date is clearly against the routine administration of multiple antenatal steroid courses. In special clinical situations, a second course of betamethasone ("rescue course”) may be justifiable. Tocolysis during administration of steroids is not routinely indicated in the absence of contractions, cervical shortening or rupture of membrane

Efficacy of a strategy to prevent neonatal early-onset group B streptococcal (GBS) sepsis

Background: Existing guidelines recommend different strategies to prevent early-onset neonatal GBS sepsis. In 1997, using our own data on incidence and risk factors, we established a new prevention strategy which includes GBS screening at 36 weeks' gestation and intrapartum antibiotic prophylaxis (IAP) in women with positive or unknown GBS colonization with at least one risk factor. The present study evaluates the efficacy of the new prevention strategy. Methods: Retrospective study of the incidence of early-onset GBS sepsis among all live births at the University Women's Hospital Basel between 1997 and 2002. Additional analysis of delivery and post partum period of all GBS sepsis cases, including GBS screening, risk factors during labor (prematurity, rupture of membranes (ROM) <12 h, intrapartum signs of infection), and IAP. Comparison of this group's characteristics G2 (9,385 live births, using the new strategy) with the previous group, G1 (1984-1993, 16,126 live births, without GBS screening or routine IAP) was performed. Results: The incidence of early-onset GBS sepsis was reduced from 1/1000 (G1) to 0.53/1000 (G2). We observed a significant reduction of overall intrapartum riskfactors in cases of GBS sepsis. Conclusion: This study suggests that our new prevention strategy is effective in reducing the incidence of early-onset GBS sepsis in neonates. In comparison, implementation of the CDC's prevention strategy might have prevented 2 additional cases in 9385 live births. However, this would have required treating a much larger number of pregnant women with IAP with consequential increasing costs, side effects and complication

Trajectories of humoral and cellular immunity and responses to a third dose of mRNA vaccines against SARS-CoV-2 in patients with a history of anti-CD20 therapy.

BACKGROUND The majority of patients with B-cell-depleting therapies show compromised vaccination-induced immune responses. Herein, we report on the trajectories of anti-SARS-CoV-2 immune responses in patients of the RituxiVac study compared with healthy volunteers and investigate the immunogenicity of a third vaccination in previously humoral non-responding patients. METHODS We investigated the humoral and cell-mediated immune response after SARS-CoV-2 messanger RNA vaccination in patients with a history with anti-CD20 therapies. Coprimary outcomes were antispike and SARS-CoV-2-stimulated interferon-γ concentrations in vaccine responders 4.3 months (median; IQR: 3.6-4.8 months) after first evaluation, and humoral and cell-mediated immunity (CMI) after a third vaccine dose in previous humoral non-responders. Immunity decay rates were compared using analysis of covariance in linear regression. RESULTS 5.6 months (IQR: 5.1-6.7) after the second vaccination, we detected antispike IgG in 88% (29/33) and CMI in 44% (14/32) of patients with a humoral response after two-dose vaccination compared with 92% (24/26) healthy volunteers with antispike IgG and 69% (11/16) with CMI 6.8 months after the second vaccination (IQR: 6.0-7.1). Decay rates of antibody concentrations were comparable between patients and controls (p=0.70). In two-dose non-responders, a third SARS-CoV-2 vaccine elicited humoral responses in 19% (6/32) and CMI in 32% (10/31) participants. CONCLUSION This study reveals comparable immunity decay rates between patients with anti-CD20 treatments and healthy volunteers, but inefficient humoral or CMI after a third SARS-CoV-2 vaccine in most two-dose humoral non-responders calling for individually tailored vaccination strategies in this population.Trial registration numberNCT04877496; ClinicalTrials.gov number

Decreased neonatal pain response after vaginal-operative delivery with Kiwi OmniCup versus metal ventouse.

BACKGROUND Vaginal delivery, especially operative assisted vaginal delivery, seems to be a major stressor for the neonate. The objective of this study was to evaluate the stress response after metal cup versus Kiwi Omnicup® ventouse delivery. METHODS The study was a secondary observational analysis of data from a former prospective randomised placebo controlled multicentre study on the analgesic effect of acetaminophen in neonates after operative vaginal delivery and took place at three Swiss tertiary hospitals. Healthy pregnant women ≥35 weeks of gestation with an estimated fetal birth weight above 2000 g were recruited after admission to the labour ward. Pain reaction was analysed by pain expression score EDIN scale (Échelle Douleur Inconfort Nouveau-Né, neonatal pain and discomfort scale) directly after delivery. For measurement of the biochemical stress response, salivary cortisol as well as the Bernese Pain Scale of Newborns (BPSN) were evaluated before and after an acute pain stimulus (the standard heel prick for metabolic testing (Guthrie test)) at 48-72 h. RESULTS Infants born by vaginal operative delivery displayed a lower pain response after plastic cup than metal cup ventouse delivery (p < 0.001), but the pain response was generally lower than expected and they recovered fully within 72 h. CONCLUSIONS Neonatal pain response is slightly reduced after use of Kiwi OmniCup® versus metal cup ventouse. TRIAL REGISTRATION Trial was registered under under NCT00488540 on 19th June 2007

Maternal outcomes and risk factors for COVID-19 severity among pregnant women.

Pregnant women may be at higher risk of severe complications associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may lead to obstetrical complications. We performed a case control study comparing pregnant women with severe coronavirus disease 19 (cases) to pregnant women with a milder form (controls) enrolled in the COVI-Preg international registry cohort between March 24 and July 26, 2020. Risk factors for severity, obstetrical and immediate neonatal outcomes were assessed. A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented with severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of caesarean section [70.7% (n = 53/75)], preterm delivery [62.7% (n = 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n = 31/75)]. In this study, several risk factors for developing severe complications of SARS-CoV-2 infection among pregnant women were identified including pulmonary comorbidities, hypertensive disorders and diabetes. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease

Time-Varying Betas and Cross-Sectional Return-Risk Relation:Evidence form the UK

The seminal study by Fama and MacBeth (1973) initiated a stream of papers testing for the cross-sectional relation between return and risk. The debate wether beta is a valid measure of risk has been renimated by Fama and French (1992) and subsequent studies. Rather than focusing on exogenous variables that have a larger explanatory power than an asset's beta in cross sectional tests, we assume the matrix of variances-covariances to follow a time varying ARCH process. Using monthly data from the UK market from February 1975 to December 1996, we compare the cross sectional return-risk relations obtained with an unconditional specification for asset's betas to those obtained when the estimated betas are based on an ARCH model. We also investigate the Pettengill, Sundaram and Mathure (1995) approach, which allows a negative cross sectional return-risk relation in periods in which the market portfolio yields a negative return relative to the risk free rate. These tests are also carried out on samples pertaining to a specific month and on samples from which a particular month is removed. Our result suggest that CAPM holds in downward moving markets than in upward moving markets hence beta is a more appropriate measure of risk in bear markets

Antenatal corticosteroids for fetal lung maturation in threatened preterm delivery: indications and administration

Antenatal maternal administration of corticosteroids has been shown to reduce morbidity and mortality rates in preterm delivery. Threatened spontaneous or medically indicated preterm delivery for maternal or fetal indications between 24 and 34 weeks of gestation with unknown fetal lung maturity status are indications for antenatal corticosteroid administration. Recent studies have challenged current practice of antenatal glucocorticoid use. The goal of this expert letter is to provide recommendations based for the clinical use of antenatal glucocorticoids based on the current evidence from published studies