Cochannel interference effect on BEP performance of SSC receiver in correlated Rician fading

We study the performance of dual branch switch and stay combining (SSC) diversity receivers operating over correlated Rician fading channels, in the presence of correlated Rayleigh distributed cochannel interference (CCI). Fast convergent infinite series representations for both the joint probability density function (PDF) of the SSC input signal-to-interference ratios (SIRs) and the PDF of the SSC output SIR are derived. The last one is applied to semi-analytically study the average bit error probability (ABEP) of differential binary phase shift keying (DBPSK). Furthermore, the optimum switching threshold in the sense of minimum ABEP is obtained numerically and the effects of fading severity and branch correlation on both ABEP and optimum switching threshold are investigated. Numerical and simulation results are presented to support the mathematical analysis.     

Paraoxonase 1 activity and phenotype distribution in premenopausal and postmenopausal women

Introduction

Postmenopausal women have higher risk of cardiovascular disease. One of the contributing factors could be reduced activity of anti-atherogenic enzyme paraoxonase 1 (PON1). The aim of this study was to examine differences in the lipid status, paraoxonase and arylesterase PON1 activities and PON1 phenotype in women with regular menstrual cycle and in postmenopausal women.

Materials and methods:

The study included 51 women in reproductive age (25 in follicular and 26 in luteal phase of the menstrual cycle) and 23 women in postmenopause. Lipid parameters in sera were determined using original reagents and according to manufacturer protocol. PON1 activity in serum was assessed by spectrophotometric method with substrates: paraoxon and phenylacetate. PON1 phenotype was determined by double substrate method.

Results:

Compared to the women in follicular and luteal phase, postmenopausal women have significantly higher concentration of triglyceride [0.9 (0.7–1.3), 0.7 (0.6–1.0) vs. 1.5 (0.9–1.7) mmol/L; P = 0.002], cholesterol [5.10 (4.78–6.10), 5.05 (4.70–5.40) vs. 6.30 (5.73–7.23) mmol/L; P < 0.001], LDL [3.00 (2.56–3.63), 3.00 (2.70–3.70) vs. 3.90 (3.23–4.50) mmol/L; P < 0.001], and apolipoprotein B [0.88 (0.75–1.00), 0.79 (0.68–1.00) vs. 1.07 (0.90–1.24) mmol/L; P = 0.002]. PON1 basal [104 (66–260), 106 (63–250) vs. 93 (71–165) U/L; P = 0.847] and salt-stimulated paraoxonase activity [210 (131–462), 211 (120–442) vs. 180 (139–296) U/L; P = 0.857] as well as arylesterase activity [74 (63–82), 70 (54–91) vs. 70 (60–81) kU/L; P = 0.906] and PON1 phenotype (P = 0.810) were not different in the study groups.

Conclusion:

There are no differences in PON1 activity and PON1 phenotype between women with regular menstrual cycle and postmenopausal women.     

Sliding manifold design for linear systems with unmatched disturbances

This paper offers an efficient sliding manifold design method that minimizes the impact of unmatched disturbances onto SM dynamics and system accuracy. System sensitivity upon unmatched constant or slowly varying external disturbance vector is evaluated by the steady-state dependent criterion function. An infinite set of sliding manifolds that minimize the chosen optimization criterion is determined and a way of selecting a manifold out of that set that provides adopted SM dynamics is suggested. The proposed approach has been demonstrated on numerical examples and verified by simulations.