“Exploring this whole thing of social justice” narrative as a tool for critical sociocultural knowledge development in teacher education

Many teacher education programs provide teachers with opportunities to read, write, and discuss critical pedagogy, with the hope that such work will allow them to develop more equitable and just teaching practices. Yet, there often remains a gap between the theoretical discussions of teaching and learning in teacher education classrooms and the pedagogical practice in those teachers’ K-12 classrooms. In this study, we examine how one teacher, Gabriela, used narratives to make connections between her third-grade classroom and the critical concepts she was exploring in a teacher education course. Embedded within an ethnographic case study of an inservice teacher education program, we used a discourse analytic approach to examine both the sociocultural knowledge and the identities Gabriela constructed through narrative as she engaged with issues of language, race, and power within the course. We consider some of the affordances of narrative in this space, including how it allowed Gabriela to integrate her understandings of multiple course topics, to position herself in multiple ways as a teacher, and to disrupt her existing understandings of race and racism in the classroom. This analysis suggests that critically oriented teacher education programs might more intentionally make space for narrative to connect critical theory and pedagogical practice.     

New insights on the utilization of ultrasonicated mustard seed cake: chemical composition and antagonistic potential for root-knot nematode,Meloidogyne javanica

This study focused, for the first time, on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC). The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles(J2 s) of root-knot nematode, Meloidogyne javanica. The results show that a 35 ppm(parts per million) concentration of a sonicated extract(SE) sample of MSC caused 65% J2 s mortality at 18 h exposure period in vitro. It also significantly suppressed the root-knot index(RKI=0.94) in tomato roots. The lethal concentration values for SE were 51.76, 29.79, and 13.34 ppm,respectively, at 6, 12, and 18 h of the exposure period, and the lethal concentration values for the non-sonicated extract(NSE)sample were 116.95, 76.38, and 55.59 ppm, respectively, at similar exposure time. Sinapine and gluconapin were identified as the major compounds in ultrasonic-assisted MSC. Because of the high extraction efficiency of metabolites in the SE, all treatments of SE were shown to be antagonistic to J2 s. Thus, this study of ultrasonication activity-based profiling of MSC may help generate target-based compounds at a scale relevant to the control of disease caused by nematodes in economic crops.     

Variations in cadmium and nitrate co-accumulation among water spinach genotypes and implications for screening safe genotypes for human consumption

Vegetables are important constituents of the human diet. Heavy metals and nitrate are among the major contaminants of vegetables. Consumption of vegetables and fruits with accumulated heavy metals and nitrate has the potential to damage different body organs leading to unwanted effects. Breeding vegetables with low heavy metal and nitrate contaminants is a cost-effective approach. We investigated 38 water spinach genotypes for low Cd and nitrate co-accumulation. Four genotypes, i.e. JXDY, GZQL, XGDB, and B888, were found to have low co-accumulation of Cd (<0.71 mg/kg dry weight) and nitrate (<3100 mg/kg fresh weight) in the edible parts when grown in soils with moderate contamination of both Cd (1.10 mg/kg) and nitrate (235.2 mg/kg). These genotypes should be appropriate with minimized risk to humans who consume them. The Cd levels in the edible parts of water spinach were positively correlated with the concentration of Pb or Zn, but Cd, Pb, or Zn was negatively correlated with P concentration. These results indicate that these three heavy metals may be absorbed into the plant in similar proportions or in combination, minimizing the influx to aerial parts. Increasing P fertilizer application rates appears to prevent heavy metal and nitrate translocation to shoot tissues and the edible parts of water spinach on co-contaminated soils.     

Glial Cells: The other cells of the nervous system

Theodor Schwann, the German physiologist who first propounded the cell theory with M Schieiden, had diverse interests. He was not only the first to isolate the enzyme pepsin, but also investigated muscle contraction and nerve structure. In the mid nineteenth century Schwann discovered that a sheath made up of myelin covered the axons of neurons in the peripheral nervous system (PNS). The cells that form the myelin are today called Schwann cells after him. Today, we know that the Schwann cells not only form the myelin sheath around neurons, but also regulate several neuronal functions and are an indispensable part of the PNS.     

Students’ views of uncertainty in formal and personal science

Background: Uncertainty is a crucial element of scientific knowledge growth. Students should have some understanding of how science knowledge is developed and why scientific conclusions are considered more or less certain than others. A component of the nature of science, it is considered an important aspect of science education and allows students to recognize the limitations of scientific research.

Purpose: This study examined Grades 5 and 9 students’ views of uncertainty in their personal scientific research and the formal scientific research of professionals.

Sample: This study included 33 students in Grade 5 (n = 17) and Grade 9 (n = 16). The students were recruited from a charter school that emphasised inquiry instruction.

Design and methods: Data were collected through interviews. Students were asked their views of their inquiry-based projects and their views of professional science.

Results: Interview data and statistical analyses indicated that students recognized uncertainty in personal science, which varied across elements of the scientific process. Additionally, their views of uncertainty in formal science tended to change across grades and knowledge of uncertainty in personal and formal science were positively correlated.

Conclusion: These findings offer insights into the processes by which students come to understand uncertainty in science and point to ways of fostering such knowledge through teaching practices.     

Brain type natriuretic peptide (BNP)—A marker of new millennium in diagnosis of congestive heart failure

The burden of disease in patients with congestive heart failure is high. The future of BNP looks promising as it may be a better diagnostic tool for the diagnosis of CHF in developing countries in new millennium. Natriuretic peptide hormones, a family of vasoactive peptides with many favourable physiological properties, have emerged as important contenders for development of diagnostic tools and therapeutic agents in cardiovascular disease. Measurement of B-type natriuretic peptide has become as an easy-to-perform bedside test. The clinical and diagnostic significance of the measurement of plasma Nt-proBNP in the diseases of the cardiovascular system with particular emphasis on the assessment of patients with heart failure and their effects on predicting survival rate. The plasma levels of Nt-proBrain Natriuretic peptide responds more vigorously after myocardial infarction than those of other natriuretic peptides. This article is an attempt to give a short overview on the utility of BNP-blood levels for the diagnosis and treatment of heart failure     

The case in case-based design of educational software: A methodological interrogation

This research assessed the value of case study methodology in the design of an educational computer simulation. Three sources of knowledge were compared to assess the value of case study: practitioner and programmer knowledge, disciplinary knowledge, and knowledge obtained from a case study of teacher practice. A retrospective analysis revealed that the case study was the source of 16 out of 23 design decisions and therefore was the most significant influence on the design of the simulation. The case study was particularly effective in sensitizing the design team to the classroom context, identifying common and uncommon teacher practices, revealing unexpected dimensions of interactions in the classroom, and generating constructive changes to the design of the simulation. Case studies can significantly enrich the design of educational software and are a promising methodological choice for design teams.

What��s Missing in Model-Based Teaching

In this study, the author investigated how four science teachers employed model-based teaching (MBT) over a 1-year period. The purpose of the research was to develop a baseline of the fundamental and specific dimensions of MBT that are present and absent in science teaching. Teacher interviews, classroom observations, and pre and post-student assessments were gathered. Using a Generate-Evaluate-Modify framework as a theoretical guide, the author identified three fundamental aspects of MBT that were not apparent in an analysis of the teaching methods. Drawing on these findings, the author hypothesizes the consequent impact of the absence of these aspects on MBT on students?? experiences and performance in science. Implications for core science teacher professional development activities on MBT are discussed.     

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.