Common macro factors and currency premia

We study the role of domestic and global factors in the payoffs of portfolios mimicking carry, dollar-carry, and momentum strategies. Using factors summarizing large data sets of macroeconomic and financial variables, we find that global equity-market factors are predictive for carry-trade returns, whereas U.S. inflation and consumption variables drive dollar-carry-trade payoffs, momentum returns are predominantly driven by U.S. inflation factors, and global factors capture the countercyclical nature of currency premia. We also find predictability in the exchange-rate component of each strategy and demonstrate strong economic value for risk-averse investors with mean-variance preferences, regardless of base currency

Penalized likelihood estimation of a trivariate additive probit model

This article proposes a penalized likelihood method to estimate a trivariate probit model, which accounts for several types of covariate effects (such as linear, nonlinear, random, and spatial effects), as well as error correlations. The proposed approach also addresses the difficulty in estimating accurately the correlation coefficients, which characterize the dependence of binary responses conditional on covariates. The parameters of the model are estimated within a penalized likelihood framework based on a carefully structured trust region algorithm with integrated automatic multiple smoothing parameter selection. The relevant numerical computation can be easily carried out using the SemiParTRIV() function in a freely available R package. The proposed method is illustrated through a case study whose aim is to model jointly adverse birth binary outcomes in North Carolina

Global political risk and currency momentum

Using a measure of political risk, relative to the United States, that captures unexpected political conditions, we show that political risk is priced in the cross section of currency momentum and contains information beyond other risk factors. Our results are robust after controlling for transaction costs, reversals, and alternative limits to arbitrage. The global political environment affects the profitability of the momentum strategy in the foreign exchange market; investors following such strategies are compensated for the exposure to the global political risk of those currencies they hold, that is, the past winners, and exploit the lower returns of loser portfolios. The risk compensation is mainly justified by the different exposures of foreign currencies in the momentum portfolio to U.S. political shocks, which is the main component of global political risk

Corona Mortis: Surgical Anatomy, Physiology and Clinical Significance

Corona mortis (CM) is classically defined as the arterial anastomosis between the obturator artery and the inferior epigastric artery that crosses the posterior aspect of the superior ramus of the symphysis pubis. Its clinical impact is considered great, as it lies within the surgical field of numerous specialties (general surgeons, orthopedists, gynecologists, urologists). Our systematic study of the literature revealed a diversity in the incidence of the Corona Mortis between cadaveric and patient studies. The new technological advances and especially the CT angiography, applied on the retropubic region vessels, have given the chance to obtain more precise depictions and thus estimations on the real incidence of corona mortis. This review intends to extract for the first time the corona mortisrsquo incidence from the major CT angiographic studies in bibliography and compare it with the incidence of CM in the major cadaveric studies. Special attention was given to the question whether this anastomosis is that important as its name implies (mortis) in the clinical setting or not

Magnetic racetrack memory: from physics to the cusp of applications within a decade

Racetrack memory (RTM) is a novel spintronic memory-storage technology that has the potential to overcome fundamental constraints of existing memory and storage devices. It is unique in that its core differentiating feature is the movement of data, which is composed of magnetic domain walls (DWs), by short current pulses. This enables more data to be stored per unit area compared to any other current technologies. On the one hand, RTM has the potential for mass data storage with unlimited endurance using considerably less energy than today's technologies. On the other hand, RTM promises an ultrafast nonvolatile memory competitive with static random access memory (SRAM) but with a much smaller footprint. During the last decade, the discovery of novel physical mechanisms to operate RTM has led to a major enhancement in the efficiency with which nanoscopic, chiral DWs can be manipulated. New materials and artificially atomically engineered thin-film structures have been found to increase the speed and lower the threshold current with which the data bits can be manipulated. With these recent developments, RTM has attracted the attention of the computer architecture community that has evaluated the use of RTM at various levels in the memory stack. Recent studies advocate RTM as a promising compromise between, on the one hand, power-hungry, volatile memories and, on the other hand, slow, nonvolatile storage. By optimizing the memory subsystem, significant performance improvements can be achieved, enabling a new era of cache, graphical processing units, and high capacity memory devices. In this article, we provide an overview of the major developments of RTM technology from both the physics and computer architecture perspectives over the past decade. We identify the remaining challenges and give an outlook on its future

Vertebral artery variations revised: origin, course, branches and embryonic development

Background: The vertebral artery originates from the subclavian artery and is divided into four segments. The aim of this study is to investigate the anatomical variations in the course and branches of the vertebral artery. Materials and methods: A research was performed via PubMed database, using the terms: “variations of vertebral artery AND cadaveric study”, “variations of vertebral artery AND cadavers” and “anomalies of vertebral artery AND cadavers”. Results: A total of 24 articles met the inclusion criteria, 13 of them referring to variations of the origin of the vertebral artery, 9 to variations of the course and 3 to variations of its branches. On a total sample of 1192 cadavers of different populations, origin of the left vertebral artery directly from the aortic arch was observed at 6.7%. In addition, among 311 cadavers, 17.4% were found with partially or fully ossified foramen of the atlas for the passage of the vertebral artery, while the bibliographic review also showed variants at the exit site of the artery from the transverse foramen of the axis. Conclusions: Despite the fact that variations of both the course and the branches of vertebral artery are in most cases asymptomatic, good knowledge of anatomy and its variants is of particular importance for the prevention of vascular complications during surgical and radiological procedures in the cervix area

Heusler-based synthetic antiferrimagnets

Antiferromagnet spintronic devices eliminate or mitigate long-range dipolar fields, thereby promising ultrafast operation. For spin transport electronics, one of the most successful strategies is the creation of metallic synthetic antiferromagnets, which, to date, have largely been formed from transition metals and their alloys. Here, we show that synthetic antiferrimagnetic sandwiches can be formed using exchange coupling spacer layers composed of atomically ordered RuAl layers and ultrathin, perpendicularly magnetized, tetragonal ferrimagnetic Heusler layers. Chemically ordered RuAl layers can both be grown on top of a Heusler layer and allow for the growth of ordered Heusler layers deposited on top of it that are as thin as one unit cell. The RuAl spacer layer gives rise to a thickness-dependent oscillatory interlayer coupling with an oscillation period of ~1.1 nm. The observation of ultrathin ordered synthetic antiferrimagnets substantially expands the family of synthetic antiferromagnets and magnetic compounds for spintronic technologies

Exploring a new ultrasound score as a clinical predictive tool in patients with rheumatoid arthritis starting abatacept: results from the APPRAISE study

Objectives To explore whether changes in a composite (power Doppler/greyscale ultrasound (PDUS)) synovitis score, developed by the OMERACT-EULAR-Ultrasound Task Force, predict disease activity outcomes in rheumatoid arthritis (RA). Methods Patients with RA who were methotrexate inadequate responders starting abatacept were evaluated. Individual joint PDUS scores were combined in the Global OMERACT-EULAR Synovitis Score (GLOESS) for metacarpophalangeal joints (MCPs) 2–5, all joints (22 paired) and a reduced (9 paired) joint set. The predictive value of changes in GLOESS at week 1–16 evaluations for clinical status and response (Disease Activity Score (DAS)28 (C reactive protein, CRP) <2.6; DAS28(CRP) ≤3.2; DAS28(CRP) ≥1.2 improvement) up to week 24, and correlations between DAS28 and GLOESS were assessed. Results Eighty-nine patients completed the 24-week treatment period. Changes in GLOESS (MCPs 2–5) from weeks 1 to 16 were unable to predict DAS28 outcomes up to week 24. However, significant improvements in GLOESS (MCPs 2–5) were observed at week 12 in patients with DAS28 ≥1.2 improvement at week 24 versus those who did not achieve that clinical response. In patients achieving DAS28 ≥1.2 improvement or DAS28 ≤3.2 at week 24, changes in GLOESS (22 and 9 paired joint sets) were greater in patients who already achieved DAS28 ≥1.2 at week 12 than in those who did not. No significant correlations were found between changes in DAS28 and GLOESS definitions at any time point. Conclusions PDUS was not correlated with clinical status or response as measured by DAS28-derived criteria, and PDUS changes were not predictive of clinical outcome. The discrepancies require further exploration. Trial registration number NCT00767325; Results