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This study was designed to investigate the impact of visual mnemonic technique on young and adult Iranian English learners' vocabulary learning. The current study followed a quasi-experimental design. 48 female students were selected based on their performance on the Quick Placement Test. The participants were divided into four groups, two experimental and two control groups. Prior to the treatment, the participants of both groups were given a pre-test to determine the knowledge of vocabulary. Then, the experimental groups received the visual mnemonic technique for 8 sessions. The control groups went through a traditional method of teaching vocabulary. After 8 sessions, a post-test was administered to all groups. Two-way ANOVA between groups was run to the results of the vocabulary tests. The results exhibited that the experimental groups who received instruction on mnemonic technique outperformed their counterparts in post-test of vocabulary. However, the differences between the effects of mnemonic technique for young and adult learners who received the specific treatment were not statistically significant (P=0.05).

The present study intended to investigate the possible effects of speech acts strategies on Iranian beginner and intermediate EFL learners' speaking ability. The first step in conducting this research was the administration of QPT [Quick Placement Test] as the homogenizing tool. It was administered to 180 beginners and intermediate EFL learners. After analyzing the results, 80 males and females as starters and 80 males and females as intermediate subjects were chosen. Then, the beginner and intermediate EFL learners were randomly divided into control and experimental groups (including 40 beginner male and 40 female EFL learners in each class). Next, a pretest of speaking was administered to all the participants and the experimental groups received speech act role play as treatment. However, the researcher did not use any treatment of speech acts in control groups. After ten sessions, the posttest was administered to all participants. The findings suggested that awareness raising on speech acts resulted in a better speaking ability as compared to the simply traditional teaching of speaking for Iranian intermediate and beginner EFL learners. Additionally, intermediate EFL learners' achievement in speaking was not in line with the beginner EFL learners' achievement in the corresponding group. Finally, it was found that gender does not interact with awareness raising on speech acts in such a way as to produce a statistically significant effect on the beginner and intermediate EFL learners' speaking ability.

The present investigation was an attempt to study the effect of using compensation and determination strategies on Iranian upper-intermediate EFL learners' vocabulary development. The question which the present study was trying to answer was: Do compensation and determination strategies have any statistically significant effects on Iranian upper- intermediate EFL learners' vocabulary development? To that end, QPT was administered to 110 female EFL learners learning English language at Shokouh Institute in Rasht, Iran. So 90 learners were selected for this study and they were divided into two experimental groups and one control group, each group contained 30 learners. Prior to the treatment, the participants were given a pretest to assess their initial knowledge of English vocabulary. The experimental groups received treatment. The researcher used compensation and determination strategies in ten sessions. However, in the control group, the new words were taught in traditional way. After ten sessions, a posttest was administered to all groups. One-way ANOVA was conducted to see if the treatment was effective or not. The results were computed and analyzed through SPSS and it was found that using compensation and determination strategies had a positive effect on the participants' vocabulary development.

This study was an attempt to investigate Iranian EFL learners' private speech across proficiency levels and gender while doing reading comprehension tasks. Moreover, it was an attempt to examine the different forms of private speech produced by Iranian English learners. Six forms of private speech were coded and analyzed: affective markers, sub-vocalization, switch from L2 to L1, repetition, unfinished sentences, and self-directed questions. It was a descriptive correlational research. The participants of this study were ninety female and male EFL learners at three levels of foreign language proficiency from two schools in Lahijan, Iran. They were selected from 110 students by administering an Oxford Quick Placement Test. Next, reading comprehension tests were administered to the participants. In order to gather data, each participant was equipped with a MP3 voice recorder to keep track of very low private speech markers while performing reading tasks. Pearson Chi-Square test was utilized to determine the probable relationship between the six forms of private speech and learners' proficiency levels and gender. The results revealed that there was statistically significant relationship between the forms of private speech produced by Iranian EFL learners and their foreign language proficiency. However, the outcomes did not yield a significant correlation regarding gender and the forms of private speech. It can be concluded that private speech is responsible for both regulating mental ability in complex tasks and facilitating internalization of mental ability. In second /foreign language learning, externalized private speech functions not just as a self-regulatory mechanism aiding problem-solving but as a tool in learning and internalizing the L2.

This study aimed to investigate the dynamic assessment of writing proficiency in Iranian English learners´ writing ability in transcendence tasks based on Vygotskian perspective. The questions which this research intended to answer were: (1) Does dynamic assessment affect Iranian English learners' writing ability? (2) Do the results of dynamic Assessment differ from the results of a non-dynamic assessment? (3) If learners progress, are they able to maintain their improved performance in the transcendence tasks when the assessment context changes? To answer the questions, 60 learners were selected following an Oxford Placement Test, and then randomly divided into two groups, experimental and control. The experimental group received dynamic assessment based instruction while control group received a non-dynamic writing instruction. After eight sessions, both groups were post tested and underwent a static and a dynamic assessment. The results indicated the outperformance of the experimental group over the control one. After two weeks, the experimental group undertook two transcendence tasks in order to trace their growing proficiency in more difficult and to increase innovative tasks. Moreover, upon analyzing the protocols, an inventory of meditational moves was detected as a posterior. As the result, the study suggests the use of dynamic assessment as a development-oriented procedure to diagnose and develop the learners´ emerging abilities.

Background and Objectives: Bisphenol A (BPA) is a toxic compound with broad applications in the plastics industry. BPA has harmful effects on various organisms and its efficient removal is necessary. The microbial degradation of BPA is a safe and economical approach. In this research, soil samples containing decaying plants were screened to isolate a BPA-degradable bacterial strain. Materials and Methods: Soil samples were collected from different locations in Damghan, Semnan province, Iran. To enrich BPA-degrading bacteria, the samples were cultured in a stepwise manner in a mineral medium containing increasing BPA concentrations (5 to 40 mg/L). The ability of isolated bacteria in degrading BPA was assayed by Folin-Ciocalteu and high-performance liquid chromatography methods. The biodegradation efficiency of the most efficient isolate was assayed under distinct conditions and it was identified through the sequencing of the 16S rRNA gene. Results: Among the isolated bacteria, Pseudomonas aeruginosa DU2 (GenBank accession number: OP919484) showed the most BPA biodegradation ability. The highest BPA degradation (52.98%) was observed in the mineral medium containing 5 mg/L BPA and the inoculum size of 6 × 107 CFU/mL at pH 9 and in the presence of 0.05% (w/v) NaCl during 10 days. Conclusion: These results offer soil containing decaying plants as a promising source for finding BPA-degrading bacteria. P. aeruginosa DU2 has basal BPA removal ability, which could be improved by optimization of medium components and growth conditions. [ABSTRACT FROM AUTHOR]

A mesophilic Enterobacter sp. Bn12 producing an alkaline thermostable lipase was isolated from soil in Tehran, Iran. The lipase gene (ELBn12) was identified from a genomic library. Sequence analysis of the DNA fragment revealed an open reading frame of 879 bp encoding a lipase with a molecular mass of 31.3 kDa. The deduced amino acid sequence showed 96% identity with a lipase of Enterobacter sp. Ag1 and the identity of their DNA sequences was 88.9%. ELBn12 belongs to the lipase subfamily I.1 and its catalytic triad consists of Ser82, Asp237 and His259. The lipase was expressed in Escherichia coli (BL21) pLysS and partially purified by anion exchange chromatography. The maximum activity of ELBn12 was obtained at temperature of 60 °C and pH 8.0 towards tricaprylin (C8) and its specific activity was around 2900 U/mg. ELBn12 was stable within a broad pH range from 6.0 to 11.0. The enzyme showed high stability in both polar and nonpolar organic solvents at 50% (v/v). The lipase activity was enhanced in the presence of 10 mM of Ca(2+), Mg(2+) and K(+), while heavy metals (Fe(3+) and Zn(2+)) had strong inhibitory effect. ELBn12 showed high activity in the presence of 1% (w/v) nonionic surfactants, however ionic surfactants inhibited the lipolytic activity. ELBn12 characteristics show that it has a potential to be used in various industrial processes.