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The major histocompatibility complex class I-related chain A (MICA), expressed on cell surface, plays an important role in the elimination of both virus-infected cells and tumor through the activation of the natural killer (NK) receptor NKG2D. A polymorphic change from methionine (Met) to valine (Val) at amino acid position 129 categorizes MICA alleles into strong and weak binders for the NKG2D receptor and has been found in a variety of immune-related disorders. In this study, we investigated the potential interaction between genetic polymorphism of MICA and the development of breast cancer. We recruited 192 unrelated Tunisian women affected by breast cancer and 205 controls age-matched women, all genotyped for MICA-129 Met/Val (rs 1051792). A significant association was found between the Val allele and Val/Val genotype and the risk of breast cancer (p = 0.002, OR = 1.64, 95% CI = [1.17-2.27]; p = 0.002, OR = 1.88, 95% CI = [1.24-2.87], respectively). After stratification with clinical-pathology parameters, we found that 71% of women aged lower than 40 years had a Val/Val genotype versus 49% (p = 0.014). About 72% of these patients having a family history of cancers had a Val/Val genotype (p = 0.04). These results suggest that tumor escape mechanism because of failure in order to activate NK cells by MICA-129 Val allele may play a role in individual susceptibility for breast cancer development in Tunisian women.

A maximum power point tracking method based on fast terminal sliding mode control (FTSMC) for photovoltaic systems is introduced in this work. The control scheme contains two loops: the first achieves the maximum power point (MPP) searching via an incremental conductance algorithm which provides the reference voltage (MPV). The second loop performs the regulation of the operating point to the reference MPV. Simulations results have proved the efficiency of the proposed method.

In this work, high-order non-singular terminal sliding-mode observers are presented. These observers are designed in order to estimate rotor fluxes and rotor speed of induction motors. The first observer provides the currents estimates which serve as an input for the second observer. The output of the second observer is the rotor fluxes estimates. Finally, estimates of the rotor fluxes are utilized to foresee rotor speed.