An Investigation into the Parameters Affecting Preparation of Polybutyl Cyanoacrylate Nanoparticles by Emulsion Polymerization

Emulsion polymerization was used to synthesize poly butyl cyanoacrylate nanoparticles in presence of steric stabilizer dextran 70. Nanoparticles were characterized by particle size analysis, scanning electron microscopy and light microscopy. Polymerization factors affecting particle size and distribution such as dextran 70, polysorbate 80 (PS 80) and H⁺ concentration, polymerization time and temperature, and sonication were studied. Distinct concentrations of stabilizer were needed to produce proper nanoparticles. In this case, the appropriate value was 2 % of total volume. At pH 4 significant decrease in production efficiency demonstrated the substantial effect of H⁺ concentration on nanoparticles. Furthermore significant increases in particle size and distribution was observed at 50 °C compared to room temperature. 0.001 % (v/v) PS 80 represented notable influence on size and distribution. In addition, shaped nanoparticles were obtained by altering polymerization time from 5.5 h to 18 h. Finally, nanoparticle features were influenced by different factors. Appropriate manipulating of such factors can lead to obtaining desirable nanoparticles.     

Evaluation of Low Blood Lead Levels and Its Association with Oxidative Stress in Pregnant Anemic Women: A Comparative Prospective Study

To correlate blood lead levels (BLLs) and oxidative stress parameters in pregnant anemic women. A total of 175 pregnant women were found suitable and included for this study. Following WHO criteria, 50 each were identified as non-anemic, mild anemic and moderate anemic and 25 were severe anemic. The age of all study subjects ranged from 24–41 years. At admission, BLLs and oxidative stress parameters were estimated as per standard protocols and subjected with ANOVA, Pearson correlation analysis and cluster analysis. Results showed significantly (p < 0.01) high BLLs, zinc protoporphyrin (ZPP), oxidized glutathione (GSSG), lipid peroxide (LPO) levels while low delta aminolevulinic acid dehydratase (δ-ALAD), iron (Fe), selenium (Se), zinc (Zn), haemoglobin (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), red blood cell (RBC) count, reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (TAC) in all groups of anemic pregnant women as compared with non anemic pregnant women. In all groups of pregnant women, BLLs showed significant (p < 0.01) and direct association with ZPP, GSSG and LPO while inverse relation with δ-ALAD, Fe, Se, Zn, Hb, Hct, MCV, MCH, MCHC, RBC, GSH, SOD, CAT and TAC. Study concluded that low BLLs perturb oxidant-antioxidant balance and negatively affected hematological parameters which may eventually Pb to Fe deficiency anemia during pregnancy.     

Bringing Disability Into the Discussion: Examining Technology Accessibility as An Equity Concern in the Field of Instructional Technology

This article presents a review of the literature, pertaining to technology accessibility in K–12 schools in the United States, in order to bring technology accessibility into conversations about equity in instructional technology with the goal of ensuring that disabled learners have equal access to the technology-enhanced learning opportunities that are an increasingly integral part of K–12 education. The findings of the review indicate that despite long-standing federal and state accessibility mandates, inaccessible technologies abound in K–12, denying disabled learners equal access to education. We conclude that technology accessibility is an equity concern that must be prioritized in instructional technology discourse, research, and practice to begin addressing the inequality that disabled learners face in technology-enhanced K–12 learning environments. (Keywords: instructional technology, equity, disability, accessibility, K–12, education)     

Iranian EFL teachers’ effectiveness of instructional behavior in public and private high schools

Over recent decades, educators have recognized the crucial importance of teaching environment and contextual factors in teaching and learning outcomes. Public and private schools are among those teaching contexts that have been in competition for teaching quality and effectiveness for many years. This study investigated the effectiveness of some English teachers in these two school contexts in a foreign language setting, Iran. Seventy-six public and private high schools in a small city in Iran were selected, and their English teachers’ performance was evaluated by an external observer and self-evaluation using a high-inference observation instrument and a questionnaire. The result of the data analysis showed that English teachers who worked in private schools were more effective teachers than their colleagues in public schools. The results also revealed that teacher effectiveness and their years of teaching experience and age were weakly but significantly related. Furthermore, it was found that teachers’ type of university degree and the location of schools (disadvantaged vs. privileged areas of the city) were not related to teachers’ effectiveness.     

Transnational corporations in education: filling the governance gap through new social norms and market multilateralism?

This paper explores the rising presence of transnational corporations (TNCs) in education and their mobilisation of global corporate social discourses to legitimise their private authority in education. The rising presence of TNCs is explored in the paper in two parts. First, through a taxonomy of global corporate social engagement (GCSE) activities and second, through a case study of the World Economic Forum’s corporate citizenship initiatives as a new form of ‘market’ multilateralism in education. Lastly, I critique the GCSE efforts of TNCs working in education and discuss the implications of their seemingly ‘to do good’ activities.     

The positive impact of othering in voluntourism: The role of the relational other in becoming another self

Despite initial enthusiasm about the potential of voluntourism to promote sustainable development and intercultural learning, recent critiques have focused on voluntourists’ tendency to reinforce status differences by “Othering” their hosts. This study expands the literature on Othering in international voluntourism contexts by examining how local community members who interacted with voluntourists interpreted the Self–Other relationship. Based on longitudinal focus group data from four host communities, the findings showed that the categories of “Self” and “Other” were not fixed but fluid, permeable, and dynamic. The study suggests that the Othering process can open up unexpected relational spaces and reconfigure community–voluntourist relationships.     

Exercise-induced hypoalgesia: Pain tolerance,preference and tolerance for exercise intensity,and physiological correlates following dynamic circuit resistance exercise

Previous research has demonstrated significant decreases in pain perception in healthy individuals following both aerobic and upper body resistance exercise, but research on circuit training has been limited. The purpose of the study was to determine the effects of a strenuous bout of dynamic circuit resistance exercise on pain threshold and pain tolerance in conjunction with changes in blood lactate levels, heart rate (HR), and perceived exertion. A sample of 24 college-age students participated in 2 sessions: (1) a maximal strength testing session and (2) a circuit training bout of exercise that consisted of 3 sets of 12 repetitions with a 1:1 work to rest ratio at 60% one-repetition maximum (1-RM) predicted from a three-repetition maximum (3-RM) for 9 exercises. Participants exhibited increases in pain tolerance, blood lactate levels, HR and perceived exertion following resistance exercise. Preference for exercise intensity was positively correlated with lactate post exercise and tolerance for exercise intensity was positively correlated with pain tolerance and lactate post exercise. In conclusion, this is the first study to demonstrate increases in pain tolerance following a dynamic circuit resistance exercise protocol and disposition for exercise intensity may influence lactate and pain responses to circuit resistance exercise.     

Response of seed tocopherols in oilseed rape to nitrogen fertilizer sources and application rates简

Tocopherols (Tocs) are vital scavengers of reactive oxygen species (ROS) and important seed oil quality indicators. Nitrogen (N) is one of the most important fertilizers in promoting biomass and grain yield in crop production. However, the effect of different sources and application rates of N on seed Toc contents in oilseed rape is poorly understood. In this study, pot trials were conducted to evaluate the effect of two sources of N fertilizer (urea and ammonium nitrate). Each source was applied to five oilseed rape genotypes (Zheshuang 72, Jiu-Er-1358, Zheshuang 758, Shiralee, and Pakola) at three different application rates (0.41 g/pot (N1), 0.81 g/pot (N2), and 1.20 g/pot (N3)). Results indicated that urea increased α-, γ-, and total Toc (T-Toc) more than did ammonium nitrate. N3 was proven as the most efficient application rate, which yielded high contents of γ-Toc and T-Toc. Highly significant correlations were observed between Toc isomers, T-Toc, and α-/γ-Toc ratio. These results clearly demonstrate that N sources and application rates significantly affect seed Toc contents in oilseed rape.