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This study aims to investigate the effects of pH and chemical reagents to model and optimize the flotation process of a complex lead ore containing 2.44 wt% Pb. For this purpose, the effects of pulp pH, collectors (PAX and R404), depressant (FeSo4), and activator (Na2S) concentrations were studied using response surface methodology. Furthermore, the influence of these parameters was studied on flotation kinetics parameters. The optimization studies indicated that the desired Pb recovery (84.1%) and grade (26.6%) was obtained from the test, which was performed with the optimum flotation conditions: 75 g/t PAX, 80 g/t FeSo4, 735 g/t Na2S, 20 g/t R404 and pH 9.5. The results of statistical analyses showed that the pulp pH, PAX concentration, and interactions between pH-R404 concentration and PAX concentration-R404 concentration were the most influential parameters on concentrate grade and recovery. From the kinetic studies, it was observed that the flotation rate coefficient and ultimate recovery were strongly dependent on the pulp pH. The flotation rate coefficient increased with enhancing the pH from 8 to 9.5 and after that reduced with increasing the pH to 11. [ABSTRACT FROM AUTHOR]

Inhibitory control plays a crucial role in cognitive functioning. We aimed to investigate the efficacy of a program for attentive rehabilitation of inhibition and selective attention (PARISA), on inhibitory control in preschool children. Thirty preschool children, (10 girls) aged six were randomly assigned to the two control and intervention groups. Flanker and Go/ No-Go tests were used to assess preschooler's inhibitory control.The analysis showed improved accuracy of the go/no-go task (P < 0.05) and the reaction time of incongruent trials in Flanker test (P < 0.05). We concluded taht Inhibitory control could be trained in younger children and PARISA is an effective program to improve inhibitory control in preschool children. [ABSTRACT FROM AUTHOR]

In this paper, the main and interaction effects of chemical reagent (collector and frother) dosages on the copper flotation performance using response surface methodology in design expert software were examined and the optimized dosage of reagents were specified. Then, in order to increase copper grade and recovery at industrial rougher flotation cells of the Miduk copper concentrator, Iran, distribution patterns of chemical reagents in suggested optimum conditions were investigated. A central composite design with three levels and five variables was employed to model and optimize the laboratory batch scale flotation process. The effect of dosages of Z11 (0–10 g/t), Flomin C4132 (14–34 g/t), A3477 (5–15 g/t) as collectors, AF65 (5–15 g/t) and MIBC (4–12 g/t) as frothers was studied. Forty-eight batch rougher flotation experiments (pH 11.5) for Miduk porphyry copper ore consisting of 0.9% Cu were conducted at different conditions using a bench scale Denver flotation cell with 3 L capacity. Second order response functions were generated for both the Cu grade and recovery models, as metallurgical indicators. These model equations were optimized using quadratic programming so as to maximize Cu grade and recovery within the experimental range studied. The main effect of all reagents dosages and the interaction of the Z11-Flomin C4132, Z11-A3477, and A3477-MIBC dosages had a significant impact on both recovery and grade. The optimum reagents dosages were found to be 5 g/t Z11, 34 g/t C4132, 5 g/t A3477, 15 g/t AF65, and 8 g/t MIBC. Maximum recovery of 91.4% and grade 8.13 were achieved under optimal conditions. Additionally, verification experiments at optimum conditions proposed by the models were carried out to specify the validity and adequacy of the predicted models. Based on the industrial rougher circuit tests results, distribution patterns of 75%-0%-25% and 50%-25%-25% were selected as the best distributions of collectors and frothers in mentioned conditions, respectively. The copper recovery and grade improved about 2% and 1.8%, respectively, via the use of optimized stage addition of reagents. [ABSTRACT FROM AUTHOR]

Introduction: Detailed assessment of behavioral disorders is of high importance, especially in preschool children. The present study aimed to compare the prevalence of behavioral disorders between preschool boys and girls and suggestion about strategies for reduction these problems. Materials and Methods: Statistical community of this descriptive study was all preschool children aged 1.5-7 years residing in Tehran during 2010-11. The study population included 2000 children were selected through multistage sampling. Each child's mother completed the Child Behavior Checklist (CBCL) and the data were analyzed using descriptive statistics, chi square and SPSS software version 18. Results: Total cases are 1977 persons included 957 boys (48.4%) and 1020 girls (51.6%). Findings indicated that attention problem was the most common disorder among preschool boys (6.1%) while emotionally reactive was the most common problem among preschool girls (17.2%). In addition, the most prevalent disorder before age 5 was emotionally reactive (11.3%). The most common disorders between ages 5 to 7 were emotionally reactive (10.7%) and somatic complaints (10.3%). In most of the behavioral problem subscales, girls experienced more problems compared to boys (P=0.001). Conclusion: Based on the results, in most of the behavioral problem subscales, girls experienced more problems compared to boys. The prevalence rate of behavioral disorders is relatively high in preschools. The issue therefore requires serious attention from mental health services authorities. [ABSTRACT FROM AUTHOR]

Background: With recent progress in the treatment of people living with HIV (PLWH) and their increased rate of survival, health-related quality of life (HRQoL) has become an important issue., Objective: In the present study, we aimed to investigate the association of current CD4 cell count, baseline CD4 cell count, nadir CD4 cell count, and plasma viral load with health-related quality of life in PLWH., Methods: Participants were 67 PLWH who were under the treatment of antiretroviral therapy (ART) in Imam Khomeini Hospital of Tehran, Iran in 2016. Participants were divided into the two groups with high and low levels of current CD4 cell count, baseline CD4 cell count, nadir CD4 cell count and plasma viral load. We used independent sample t-test for data analysis using SPSS 22 software., Results: Our results demonstrated that for current CD4 cell count, the group differences were significant for total scores of HRQoL (P=0.028), also in the components of physical functioning (P=0.032), role limitation due to physical health problems (P=0.006), and role limitation due to emotional problems (P=0.009). Our data analysis showed that for baseline CD4 cell count (P=0.62), nadir CD4 cell count (P=0.29), and viral load group (P=0.78), the differences were not significant for HRQoL., Conclusion: Knowing the association between current CD4 count and health-related quality of life, adherence to ART might be a motivator for PLWH to enhance their health-related quality of life., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)