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First-principles calculations, with CASTEP code, were employed to study the effect of lithium (Li) and beryllium (Be) doping on structural stability, phase transformation, electronic band structure and optical characteristics of CaTiO 3 . The substitution of Ca-atoms with the Li-and Be-atoms changes the lattice parameters and hence unit cell volume and consequently the electronic band structure of CaTiO 3 is modified. With 12.5% Li-and Be-doping, we observed a structural phase transformation from cubic to pseudo-cubic tetragonal structure which is in good agreement with the literature. The impact of structural phase transformation on the electronic band structure has been explained with the help of total, partial and elemental partial density of states. In case of Li-doping, the value of band gap slightly increases from 1.866 to 1.964 eV while the band gap value decreases to 1.614 eV for Be-doping. In both cases of doping, maxima of valence band are shifted from R to Z symmetry point whereas the minima of conduction band remain at G symmetry point. In pure and doped cases, the nature of the band gap remains unaltered, i.e., indirect band gap. From optical response of the doped compounds, we perceive a red shift in the absorption. With Be-and Li-doping, the static refractive index also increased from 2.48 to 2.63 and 4.1, respectively. The change in electronic structure and optical characteristic with Li-and Be-doping would make this compound a suitable candidate for future optoelectronic devices.

Intellectual disability (ID), also called mental retardation, is defined by below-average intelligence or mental aptitude as well as a lack of life skills. It has a significant association with residency, family history, and chromosomal disorder. An analytical cross-sectional study was performed over a period from December 2019 to January 2021 in special educations centers and hospitals of Lahore, Faisalabad, Shahkot, Sialkot, Gujranwala and Sangala, Punjab, Pakistan. This study was aimed to access the prevalence and risk factors of Intellectual disability (ID). Questionnaires were designed and filled with the help of general doctors, pediatricians, and psychiatrists who diagnosed both intellectual and adaptive functioning of individuals Association between these parameters was analyzed by using SPSS software (Chi-square test) between ID and risk factors and the level of significance was considered as P<0.05. The frequency of mild, moderate, severe, and profound ID was 46.7 %, 32.1 %, 14.6 %, and 6.7 % respectively. More males (56.82 %) as compared to females 43.17 % were observed.

In this paper we proposed Bayes estimators for complete sample of the Modified InverseRayleigh (MIR) parameters which was introduced by Khan (2014). Different approximationmethods with squared error loss function (SELF) have been used to develop the bayesestimators for the unknown parameters. The proposed estimators are compared with the correspondingmaximum likelihood estimators by simulation study on the basis of mean squareerror (MSE). To illustrate the usefulness and goodness of fit of Modified Inverse Rayleighdistribution we considered two real data sets.