لیلا فلاح

Drought stress is one of the most important factors limiting the survival and growth of plants in the Drought stress is one of the most important factors limiting the survival and growth of plants in the different habitats of Iran. Detailed knowledge about the ecophysiological responses of native plants to drought stress could contribute to the success of re-vegetation programs. Different accessions of two perennial chamomiles، Anthemis tinctoria and Tripleurospermum servanes were subjected to four drought treatments، i. e. well-watered (control)، mild drought stress (75% field capacity)، moderate drought stress (55% field capacity)، and sever drought stress (35% field capacity). Osmotic solutes (proline and soluble sugars)، Relative water content (RWC)، antioxidant enzymes (peroxidase and polyphenoloxidase) and pigments were investigated. Drought stress significantly increased accumulations of osmotic solutes، but decreased relative water content، total proteins content، dry matter percentage in the studied species. In both species the chlorophyll a and total chlorophyll contents did not changed in drought stresses، however the cartenoids content and the ratio of cartenoids to total chlorophylls significantly increased. Although the peroxidase activity، as an antioxidant enzyme، of all three accessions of T. servanes increased in sever drought stress، but in two accessions (of three accessions) A. tinctoria considerably decreased. These findings suggested that the A. tinctoria and T. servanes showed a moderate tolerance to drought، although in both species some accessions had higher tolerance to sever drought stress than the other accessions due to higher capacities of osmotic adjustment.

Background and Many of the students with mathematical problems show poor problem-solving skills. Present study aimed to investigate the efficacy of problem-solving assistant training software on improvement of problem-solving skills among elementary school students with mathematics disorder. Present research was a quasi-experimental study with pretest-posttest control group design. Study sample consisted of 30 students with mathematics disorders, who were selected using random cluster sampling method among all the female fourth and fifth graders with mathematics disorder that where studying in elementary schools of Qaemshahr City. These students were selected using Wechsler Intelligence Scale for Children (Shahim, 2006) and Iran Key math Test (Mohammad Ismael & Houman, 2002). Participants randomly assigned to control and experimental groups. Experimental group received eight 45-minute training sessions using problem-solving assistant software, while control group received no training. Data was analyzed using mixed-design analysis of variance for repeated measures. Results showed that experimental group gained significantly higher scores in problem-solving posttest comparing to control group (p < 0.001). Therefore, according to our findings, problem-solving assistant training software could significantly improve problem-solving skills among students with mathematics disorder. Moreover, the results of a 3-month follow up showed stability in learnt lessons. According to the findings of current study, the administration of effective training software can be advantageous in treatment of learning disabilities. Implications are discussed in the paper.