Face masks for the public during the covid-19 crisis

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Martingales, Detrending Data, and the Efficient Market Hypothesis

We discuss martingales, detrending data, and the efficient market hypothesis for stochastic processes x(t) with arbitrary diffusion coefficients D(x,t). Beginning with x-independent drift coefficients R(t) we show that Martingale stochastic processes generate uncorrelated, generally nonstationary increments. Generally, a test for a martingale is therefore a test for uncorrelated increments. A detrended process with an x- dependent drift coefficient is generally not a martingale, and so we extend our analysis to include the class of (x,t)-dependent drift coefficients of interest in finance. We explain why martingales look Markovian at the level of both simple averages and 2-point correlations. And while a Markovian market has no memory to exploit and presumably cannot be beaten systematically, it has never been shown that martingale memory cannot be exploited in 3-point or higher correlations to beat the market. We generalize our Markov scaling solutions presented earlier, and also generalize the martingale formulation of the efficient market hypothesis (EMH) to include (x,t)-dependent drift in log returns. We also use the analysis of this paper to correct a misstatement of the fair game condition in terms of serial correlations in Fama's paper on the EMH

A Century of Cardiomythology: Exercise and the Heart c.1880–1980

The relationship between health and exercise involves risks as well as rewards. This article focuses on heart disease and the marathon to show how doctors have negotiated that relationship over a century. Three distinct changes in biomedical attitudes towards vigorous exercise are outlined. First, the mid-Victorian interpretation of pathological hypertrophy of the heart was overturned at the end of the nineteenth century. Secondly, hypertrophy was reinvented as a beneficial physiological adaptation in the 1940s and 1950s. Thirdly, these claims of distinctiveness were challenged by the leisure revolution. Sports doctors and cardiologists reinvented exercise as a drug that could only be safely used with the guidance of a medical professional. Medicalising sport reduced its risk and maximised its reward, both to the individual and the state

Endocannabinoid and steroid analysis in infant and adult nails by LC-MS/MS

A common method to quantify chronic stress is the analysis of stress markers in keratinized matrices such as hair or nail. In this study, we aimed to validate a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the combined quantification of steroid hormones and endocannabinoids (eCBs) in the keratinized matrix nail. Furthermore, we aimed to investigate the suitability of the nail matrix for the detection of these stress markers in a pilot study. An LC-MS/MS method was used for the simultaneous identification and quantification of four eCBs (2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA), palmitoylethanolamide (PEA)) and five steroid hormones (cortisol, cortisone, androstenedione, progesterone, testosterone) in human nails using a surrogate analyte method for each analyte. The method was validated in terms of selectivity, response factor, linearity, limit of quantification (LOQ), precision, accuracy, matrix effect, recovery, robustness, and autosampler stability. Nail samples were extracted for 1 h with methanol following a clean-up with a fully automated supported liquid extraction (SLE). The influence of nail weight on the quantification was investigated by using 0.5-20 mg of nail sample. As a proof of concept, nail samples (N = 57) were analyzed from a cohort representing newborns (1 month old), children (between 1 and 10 years), and adults (up to 43 years). It could be shown that the established workflow using a 1 hour extraction and clean-up by SLE was very robust and resulted in a short sample preparation time. The LC-MS/MS method was successfully validated. Matrix effects with ion enhancement occurred mainly for 2-AG. Sample weights below 5 mg showed variations in quantification for some analytes. Certain analytes such as PEA and progesterone could be accurately quantified at a sample weight lower than 5 mg. This is the first study where steroids and eCBs could be simultaneously detected and quantified in infant and adult nails. These results show that nails may serve as an alternative keratinized matrix (compared to hair) for the retrospective monitoring of cumulative eCB and steroid hormone levels. The combined assessment of eCBs and steroids from nails could provide a new approach to gain new insights into stress exposure in newborns and adults

Impact of SARS-CoV-2 on incidence, treatment and outcome of very preterm born infants in Switzerland: a retrospective, population-based cohort study.

AIMS OF THE STUDY To assess whether the COVID-19 pandemic caused by SARS-CoV-2 had an impact on incidence, treatment or major adverse short-term outcome of preterm-born infants in Switzerland. METHODS Retrospective cohort study of preterm infants born in 2020 based on two independent data sources from the Swiss Federal Statistics Office (FSO) and SwissNeoNet. Based on FSO data, we calculated the odds ratios for extremely preterm (22-27 weeks gestation), very preterm (28-31 weeks gestation), and late preterm (32-36 weeks gestation) births during the pandemic. Based on SwissNeoNet data of infants born between 22 and 31 weeks gestation, we compared infants born during the Swiss lockdown period in 2020 with infants born during the same period between 2015 and 2019, all infants of 2020 with all infants between 2015 and 2019 and infants born to mothers tested SARS-CoV-2 positive and negative. Possible associations with the pandemic were tested using logistic regression adjusted for case-mix. As a control, we compared births of 2019 with those of 2015-2018. RESULTS The FSO data revealed equivalent odds for extremely preterm births in 2020 (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.89-1.14), as well as somewhat lower odds ratios for very preterm (OR 0.9, 95% CI 0.82-1.00) and late preterm (OR 0.91, 95% CI 0.88-0.93) births in 2020. A comparison between 2019 and 2015-2018, however, revealed matching odds ratios rendering an association to the pandemic unlikely. In the SwissNeoNet data, 137 infants were born during lockdown in 2020 compared with 134 births per year during 2015-2019. When including all infants, 744 infants were compared to 845 births, respectively. The only difference observed in treatments and short term outcomes between 2020 and the reference years were a higher odds for respiratory distress syndrome (OR 1.6, 95% CI 1.08-2.37) and provision of continuous positive airway pressure (CPAP) (OR 1.39, 95% CI 1.05-1.84). CONCLUSIONS Our Swiss population-based analysis did not identify the elsewhere reported association between the COVID-19 pandemic and a reduced preterm birth rate. However, we can confirm a possible link between the COVID-19 pandemic and higher odds of respiratory distress syndrome, possibly coupled with CPAP requirements. Further observation of potential effects of the pandemic on health and health care provision to newborns may however be indicated based on the literature available so far and that our data only covers the first 9 months of the current pandemic

Impact of SARS-CoV-2 on incidence, treatment and outcome of very preterm born infants in Switzerland: a retrospective, population-based cohort study

AIMS OF THE STUDY: To assess whether the COVID-19 pandemic caused by SARS-CoV-2 had an impact on incidence, treatment or major adverse short-term outcome of preterm-born infants in Switzerland. METHODS: Retrospective cohort study of preterm infants born in 2020 based on two independent data sources from the Swiss Federal Statistics Office (FSO) and SwissNeoNet. Based on FSO data, we calculated the odds ratios for extremely preterm (22-27 weeks gestation), very preterm (28-31 weeks gestation), and late preterm (32-36 weeks gestation) births during the pandemic. Based on SwissNeoNet data of infants born between 22 and 31 weeks gestation, we compared infants born during the Swiss lockdown period in 2020 with infants born during the same period between 2015 and 2019, all infants of 2020 with all infants between 2015 and 2019 and infants born to mothers tested SARS-CoV-2 positive and negative. Possible associations with the pandemic were tested using logistic regression adjusted for case-mix. As a control, we compared births of 2019 with those of 2015-2018. RESULTS: The FSO data revealed equivalent odds for extremely preterm births in 2020 (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.89-1.14), as well as somewhat lower odds ratios for very preterm (OR 0.9, 95% CI 0.82-1.00) and late preterm (OR 0.91, 95% CI 0.88-0.93) births in 2020. A comparison between 2019 and 2015-2018, however, revealed matching odds ratios rendering an association to the pandemic unlikely. In the SwissNeoNet data, 137 infants were born during lockdown in 2020 compared with 134 births per year during 2015-2019. When including all infants, 744 infants were compared to 845 births, respectively. The only difference observed in treatments and short term outcomes between 2020 and the reference years were a higher odds for respiratory distress syndrome (OR 1.6, 95% CI 1.08-2.37) and provision of continuous positive airway pressure (CPAP) (OR 1.39, 95% CI 1.05-1.84). CONCLUSIONS: Our Swiss population-based analysis did not identify the elsewhere reported association between the COVID-19 pandemic and a reduced preterm birth rate. However, we can confirm a possible link between the COVID-19 pandemic and higher odds of respiratory distress syndrome, possibly coupled with CPAP requirements. Further observation of potential effects of the pandemic on health and health care provision to newborns may however be indicated based on the literature available so far and that our data only covers the first 9 months of the current pandemic

Langzeit-Monitoring der Auswirkungen einer Umstellung auf den biologischen Landbau (MBUIL V), Abschlussbericht

Auf einem Ackerbaubetrieb im Marchfeld in Niederösterreich wird seit dem Jahr 2003 eine umfassende Langzeituntersuchung zur Dokumentation und Entwicklung des biologischen Landbaus und agrarökologischer Begleitmaßnahmen durchgeführt (www.mubil.boku.ac.at). In der Projektphase MUBIL V wurden im Jahr 2014 spezifische Themen aus dem Gesamtmonitoring ausgewählt und fortgeführt. Die Untersuchungen fanden auf Betriebs-, Schlag- und Parzellenebene statt. Die Ziele des Projektes waren: (a) Wissenschaftlich abgesicherte Erkenntnisse über das Ausmaß und die Geschwindigkeit von Veränderungen der pflanzenbaulichen Entwicklung mit der längerfristigen biologischen Bewirtschaftung zu erhalten. (b) Erkenntnisse über die Auswirkungen unterschiedliche Düngungssysteme viehloser und viehhaltender biologischer Bewirtschaftung mithilfe pflanzenbaulicher Untersuchungen über vergleichende Versuchsanstellungen zu erlangen. (c) Erkenntnisse über die Wirkungen von Blühstreifen mit unterschiedlichen Ansaatmischungen und Pflegemaßnahmen auf die Wildbienen zu dokumentieren

HERA Anomaly and Hard Charm in the Nucleon

We explore the possibility that the excess neutral and charged current events seen by the H1 and ZEUS Collaborations at HERA at large x and Q^2 could arise from a hard charm component of the nucleon. While the symmetric intrinsic charm hypothesis is unable to account for the HERA anomaly, a non-symmetric charm distribution generated non-perturbatively, for which c-bar is much harder than c, can produce significant enhancement of cross sections at the HERA kinematics.Comment: extra figure included, version to appear in Phys. Lett.

Association between perinatal interventional activity and 2-year outcome of Swiss extremely preterm born infants: a population-based cohort study.

To investigate if centre-specific levels of perinatal interventional activity were associated with neonatal and neurodevelopmental outcome at 2 years of age in two separately analysed cohorts of infants: cohort A born at 22-25 and cohort B born at 26-27 gestational weeks, respectively. Geographically defined, retrospective cohort study. All nine level III perinatal centres (neonatal intensive care units and affiliated obstetrical services) in Switzerland. All live-born infants in Switzerland in 2006-2013 below 28 gestational weeks, excluding infants with major congenital malformation. Outcomes at 2 years corrected for prematurity were mortality, survival with any major neonatal morbidity and with severe-to-moderate neurodevelopmental impairment (NDI). Cohort A associated birth in a centre with high perinatal activity with low mortality adjusted OR (aOR 0.22; 95% CI 0.16 to 0.32), while no association was observed with survival with major morbidity (aOR 0.74; 95% CI 0.46 to 1.19) and with NDI (aOR 0.97; 95% CI 0.46 to 2.02). Median age at death (8 vs 4 days) and length of stay (100 vs 73 days) were higher in high than in low activity centres. The results for cohort B mirrored those for cohort A. Centres with high perinatal activity in Switzerland have a significantly lower risk for mortality while having comparable outcomes among survivors. This confirms the results of other studies but in a geographically defined area applying a more restrictive approach to initiation of perinatal intensive care than previous studies. The study adds that infants up to 28 weeks benefited from a higher perinatal activity and why further research is required to better estimate the added burden on children who ultimately do not survive

Principles of Periodontology

Periodontal diseases are among the most common diseases affecting humans. Dental biofilm is a contributor to the etiology of most periodontal diseases. It is also widely accepted that immunological and inflammatory responses to biofilm components are manifested by signs and symptoms of periodontal disease. The outcome of such interaction is modulated by risk factors (modifiers), either inherent (genetic) or acquired (environmental), significantly affecting the initiation and progression of different periodontal disease phenotypes. While definitive genetic determinants responsible for either susceptibility or resistance to periodontal disease have yet to be identified, many factors affecting the pathogenesis have been described, including smoking, diabetes, obesity, medications, and nutrition. Currently, periodontal diseases are classified based upon clinical disease traits using radiographs and clinical examination. Advances in genomics, molecular biology, and personalized medicine may result in new guidelines for unambiguous disease definition and diagnosis in the future. Recent studies have implied relationships between periodontal diseases and systemic conditions. Answering critical questions regarding host‐parasite interactions in periodontal diseases may provide new insight in the pathogenesis of other biomedical disorders. Therapeutic efforts have focused on the microbial nature of the infection, as active treatment centers on biofilm disruption by non‐surgical mechanical debridement with antimicrobial and sometimes anti‐inflammatory adjuncts. The surgical treatment aims at gaining access to periodontal lesions and correcting unfavorable gingival/osseous contours to achieve a periodontal architecture that will provide for more effective oral hygiene and periodontal maintenance. In addition, advances in tissue engineering have provided innovative means to regenerate/repair periodontal defects, based upon principles of guided tissue regeneration and utilization of growth factors/biologic mediators. To maintain periodontal stability, these treatments need to be supplemented with long‐term maintenance (supportive periodontal therapy) programs