Background Mendelian randomization studies perform instrumental variable (IV) analysis using genetic IVs. Results of individual Mendelian randomization studies can be pooled through meta-analysis. We explored how different variance estimators influence the meta-analysed IV estimate. Methods Two versions of the delta method (IV before or after pooling), four bootstrap estimators, a jack-knife ...

We study the classical problem of the existence of irreducible plane curves with given degree d and prescribed singularities of topological types S1 ; : : : ; Sr. Our main results concern substantial improvements of the leading coeecients in the asymptotically optimal suucient conditions for complex plane curves which were found in GLS1]. We then transfer these results to real plane curves.

Instrumental variables (IV) estimators are well established to correct for measurement error on exposure in a broad range of fields. In a distinct prominent stream of research IV's are becoming increasingly popular for estimating causal effects of exposure on outcome since they allow for unmeasured confounders which are hard to avoid. Because many causal questions emerge from data which suffer ...

This paper considers the problem of prediction in a panel data regression model with spatial autocorrelation. In particular, we consider a simple demand equation for cigarettes based on a panel of 46 states over the period 1963-1992. The spatial autocorrelation due to neighboring states and the individual heterogeneity across states is taken explicitly into account. We derive the best linear un...

OBJECTIVES The purpose of this study was to investigate the prognostic value of global longitudinal strain (GLS) in heart failure with reduced ejection fraction (HFrEF) patients in relation to all-cause mortality. BACKGROUND Measurement of myocardial deformation by 2-dimensional speckle tracking echocardiography, specifically GLS, may be superior to conventional echocardiographic parameters, ...

We investigated whether dendritic cells (DCs) play a role in favoring granular lymphocyte (GL) proliferation in patients with lymphoproliferative disease of granular lymphocytes (LDGL). The presence of in vivo circulating DCs was studied in 11 patients (5 CD3+ and 6 CD3- LDGL). Autologous immature (iDCs) and mature (mDCs) DCs generated in vitro were studied for stimulatory activity on cell prol...

This study aimed to test the ability of real-time three-dimensional echocardiography (RT3DE) to characterize early abnormalities of right ventricular (RV) structure and function with preserved left ventricular (LV) ejection fraction (EF) in uremic patients undergoing peritoneal dialysis (PD). Sixty-six uremic patients with preserved left ventricular ejection fraction (> 50% LVEF) undergoing per...

BACKGROUND Type 2 diabetes mellitus (T2DM) complicated by retinopathy is associated with altered left ventricular (LV) structure and resting myocardial dysfunction unlike T2DM without retinopathy. The myocardial response to stress has not been compared in patients with and without diabetic retinopathy. The aim of this retrospective study was to determine the relationship between retinopathy and...

In structural dynamic discrete choice models, unobserved or mis-measured state variables may lead to biased parameter estimates and misleading inference. this paper, we show that instrumental can address such measurement problems when they relate evolve exogenously from the perspective of individual agents (i.e., market-level states). We define a class linear estimators rely on Euler equations ...

In this paper an implicit (double) shifted QR-method for computing the eigenvalues of companion and fellow matrices will be presented. Companion and fellow matrices are Hessenberg matrices, that can be decomposed into the sum of a unitary and a rank 1 matrix. The Hessenberg, the unitary as well as the rank 1 structures are preserved under a step of the QR-method. This makes these matrices suita...