Presence of hazardous heavy metals particularly cadmium (Cd) in agricultural soil of Faisalabad city is becoming a serious health hazard as well as loss in valuable nutritionous crops like wheat. To address such concerns, contemporary research was designed to investigate response of wheat at two morpho-physiological stages of wheat (Tillering & Boot) against cadmium. The mitigation of cadmium stress with economically and environmentally friendly osmoprotectant moringa leaf extract (3% aqueous) was addressed along with synthetic osmoprotectant ascorbic acid. Ascorbic acid is well known compound for its antioxidant properties. Moringa leaf extract also consist of many important micro and macronutrients which may be helpful for plant to recover from abiotic stresses. This diversified plant extract can be used as potential osmoprotectant against cadmium stress. To understand special effects of moringa leaf extract and ascorbic acid against cadmium stress in wheat, a pot experiment was designed in two consecutive years 2014-15 and 2015-16. The results presented in the form of graphs and tables are taken as average of two-year trial on wheat with proposed treatments. Growth attributes showed deleterious effect of cadmium alone but combine effect of cadmium with MLE resulted in enhanced growth, though it was slightly less than non-stresses (control) plants, but still effect of MLE followed by AsA was appreciatable on growth at 500µM Cd than other level of cadmium tested during current study. Inhibitory effect of cadmium was also observed in case of reduced photosynthetic activity, water related attributes and gas exchange attributes. This showed an overall effect of photosynthetic machinery and water balance of wheat cultivars under stress. Reduction in growth may be related to reduce photosynthetic activity and can be referred to as stress avoidance by plant to utilize its energy for developmental process at later stages. This may be the result of high photosynthetic rate at booting stage than tillering stage as data recorded in current experiment. MLE and AsA positively correlated with cadmium. Biochemical attributes also showed a negative response with both levels of cadmium. At the onset of cadmium stress, wheat cultivars start producing reactive oxygen species which effect wheat physiology. Lipid peroxidation was also enhanced with cadmium. But combined effect of cadmium and MLE caused mitigation of stress by decreasing lipid peroxidation and H2O2 activity. Ascorbic acid was also good enough to mitigate cadmium stress. Enzymatic and non-enzymatic antioxidants were also showed differential behavior with different treatments with and without cadmium at both stages of wheat. Cadmium (1000µM) treatment adversely affects plant by reducing SOD, POX, CAT and total soluble protein activity. This showed sensitivity for wheat cultivars at this level of cadmium stress while 500µM level of cadmium stress can be overcome by foliar treatment of MLE and AsA by producing enough antioxidants to manifest tolerance in wheat plant. For most of the enzymatic antioxidants, booting stage showed enhanced activity under stress to create tolerance in both cultivars. Galaxy-13 is more tolerant variety than Faisalabad-08 for enzymatic antioxidants. Non-enzymatic antioxidants also played potential role to combate cadmium with foliar application of MLE and AsA to enhance survival rate of wheat. A few of non-enzymatic antioxidanted like ascorbic acid, glycine betaine, proline, total soluble sugar, total soluble phenolics, alpha tocopherol, total free amino acid was tested to check their role as asmoprotectant and non-enzymatic antioxidant. Ascorbic acid activity was enhanced with cadmium stress which was further enhanced by MLE and AsA. Cadmium stimulated the innate mechanism of wheat by increasing ascorbate contents. All other osmoprotectants enhanced slightly with 500µM cadmium but adversely decreased with 1000µM cadmium. Potential phenolics like quercetin, gallic acid, ferulic acid, m-coumeric acid and chlorogenic acid accumulated in wheat with MLE at both stages. Data for yield attributes were collected only at boot stage. Yield of wheat attributes were judged for reduced number of fertile tillers, spikes and spikelets per plant and spike respectively and 1000 grain weight (g). MLE improved all above-mentioned parameters better than AsA by mitigating advere effects of cadmium stress in wheat.
The present study explores students’ perception regarding internet usage and its impact on their academic performance at elementary level in district Peshawar, KP. The study was quantitative in nature. The population includes both (male and female) elementary schools of district Peshawar, KP. Purposive sampling technique was used. The data was collected from (141) students through close-ended questionnaire based on five point Likert’s scale. The collected data was tabulated and analyzed by using MS word, SPSS software and Chi-square. The major conclusions show that both male and female students were having same views about using internet and agree that using internet makes their study more convenient, useful and improve their learning skills. It helps in improving their grades. The study concludes that while using internet, the students are also facing some problems such as shortage of power, affects eyesight and critical thinking and pain in shoulders etc. Some recommendations made by the study were that proper training and guidance may be provided to students for using internet.
Regression analysis is widely used in manyelds such as economics,nance, technology and social sciences. A linear regression model describes the relationship between dependent variable and one or more regressors. A problem named multicollinearity is the existence/presence of nearly linear dependency among regressors. The existence of severe multicollinearity questions the accuracy of the parameters estimate in a linear regression model, because the variance of the ordinary least square estimator (OLSE) would be large enough. Therefore, detection of multicollinearity can be considered asrst step for giving solution of this problem. There are several indicators (diagnostic measures) for the quanti cation of collinearity among regressors available in the literature. Widely used and the most suggested diagnostics are values of pair-wise correlations among regressors, overall R2, VIF and tolerance limit, eigenvalues, condition number and condition indices etc. However, there is no unique method that can detect and measure the existence and strength of multicollinearity in data. For remedy or reduction of collinearity among regressors, biased estimators are suggested such as the ridge and Liu estimators in literature and are alternative to the OLSE. These alternative methods also improve the accuracy of the parameter estimates of linear regression models. The biased methods resemble each other and are based on similar principals. In this study, we propose two new detection methods for indication of collinearity vi existence and developed 3 packages in R language namely mctest, lmridge and liureg. The package mctest computes already existing collinearity diagnostic measures and our proposed measures. We also compare existing and our proposed collinearity diagnostics measures for the detection of collinearity existence among regressors. Our proposed collinearity diagnostics not only perform well for simulated but also for real collinear data sets. For computation and detection of existence of collinearity mctest package can be used. The package contains functions omcdiag for computation of overall and imcdiag for individual collinearity diagnostics as described in Chapter 3, Section 3.5. For estimation and testing of ridge coe cients, the ridge package lmridge can be used to compute ridge coe cients, di erent existing biasing parameters available in literature and testing of ridge coe cients with 15 ridge related statistics such as R2, adjusted-R2, mean square error and e ective degrees of freedom etc. Similarly, estimation and testing of Liu coe cient can be done using package liureg package. It computes biasing parameters from (Liu, 1993) and the Liu related statistics. In addition, numerical comparisons between existing estimator of ridge and Liu are also done by using existing collinear data set from Hald (1952), Longley (1967) and Malinvaud (1968).