Parametric Portfolio Policies: Exploiting Characteristics in the Cross Section of Equity Returns

We propose a novel approach to optimizing portfolios with large numbers of assets. We model directly the portfolio weight in each asset as a function of the asset's characteristics. The coefficients of this function are found by optimizing the investor's average utility of the portfolio's return over the sample period. Our approach is computationally simple, easily modified and extended, produces sensible portfolio weights, and offers robust performance in and out of sample. In contrast, the traditional approach of first modeling the joint distribution of returns and then solving for the corresponding optimal portfolio weights is not only difficult to implement for a large number of assets but also yields notoriously noisy and unstable results. Our approach also provides a new test of the portfolio choice implications of equilibrium asset pricing models. We present an empirical implementation for the universe of all stocks in the CRSP-Compustat dataset, exploiting the size, value, and momentum anomalies.

Overview of microbial NGS for clinical and public health microbiology

Next-generation sequencing (NGS) has revolutionised the way we perform clinical and public health microbiology. This technology combined with the bioinformatics research field has led to a deeper understanding of the mechanisms involved in the pathogenesis of clinical infections, antimicrobial-resistant determination and dissemination of microorganisms inside the hospital, in the community, in animals and the environment. New approaches, like machine-learning methods, will even further potentiate the understanding of the information that is generated through NGS. In this book chapter, we aim to show the possibilities for NGS, including whole-genome sequencing (WGS) and metagenomics, in the fields of clinical and public health microbiology and speculate on its future importance.</p

Complete Genome Sequences of Two Methicillin-Resistant Staphylococcus haemolyticus Isolates of Multilocus Sequence Type 25, First Detected by Shotgun Metagenomics

The emergence of nosocomial infections by multidrug-resistantStaphylococcus haemolyticusisolates has been reported in several European countries. Here, we report the first two complete genome sequences ofS. haemolyticussequence type 25 (ST25) isolates 83131A and 83131B. Both isolates were isolated from the same clinical sample and were first identified through shotgun metagenomics

Complete Genome Sequences of Two Methicillin-Resistant Staphylococcus haemolyticus Isolates of Multilocus Sequence Type 25, First Detected by Shotgun Metagenomics

The emergence of nosocomial infections by multidrug-resistantStaphylococcus haemolyticusisolates has been reported in several European countries. Here, we report the first two complete genome sequences ofS. haemolyticussequence type 25 (ST25) isolates 83131A and 83131B. Both isolates were isolated from the same clinical sample and were first identified through shotgun metagenomics

Enterococcus faecium:from microbiological insights to practical recommendations for infection control and diagnostics

Early in its evolution, Enterococcus faecium acquired traits that allowed it to become a successful nosocomial pathogen. E. faecium inherent tenacity to build resistance to antibiotics and environmental stressors that allows the species to thrive in hospital environments. The continual wide use of antibiotics in medicine has been an important driver in the evolution of E. faecium becoming a highly proficient hospital pathogen.For successful prevention and reduction of nosocomial infections with vancomycin resistant E. faecium (VREfm), it is essential to focus on reducing VREfm carriage and spread. The aim of this review is to incorporate microbiological insights of E. faecium into practical infection control recommendations, to reduce the spread of hospital-acquired VREfm (carriage and infections). The spread of VREfm can be controlled by intensified cleaning procedures, antibiotic stewardship, rapid screening of VREfm carriage focused on high-risk populations, and identification of transmission routes through accurate detection and typing methods in outbreak situations. Further, for successful management of E. faecium, continual innovation in the fields of diagnostics, treatment, and eradication is necessary

Future potential of metagenomics in clinical laboratories

INTRODUCTION: Rapid and sensitive diagnostic strategies are necessary for patient care and public health. Most of the current conventional microbiological assays detect only a restricted panel of pathogens at a time or require a microbe to be successfully cultured from a sample. Clinical metagenomics next-generation sequencing (mNGS) has the potential to unbiasedly detect all pathogens in a sample, increasing the sensitivity for detection and enabling the discovery of unknown infectious agents. AREAS COVERED: High expectations have been built around mNGS; however, this technique is far from widely available. This review highlights the advances and currently available options in terms of costs, turnaround time, sensitivity, specificity, validation, and reproducibility of mNGS as a diagnostic tool in clinical microbiology laboratories. EXPERT OPINION: The need for a novel diagnostic tool to increase the sensitivity of microbial diagnostics is clear. mNGS has the potential to revolutionise clinical microbiology. However, its role as a diagnostic tool has yet to be widely established, which is crucial for successfully implementing the technique. A clear definition of diagnostic algorithms that include mNGS is vital to show clinical utility. Similarly to real-time PCR, mNGS will one day become a vital tool in any testing algorithm