A microfluidic co-culture system to monitor tumor-stromal interactions on a chip

The living cells are arranged in a complex natural environment wherein they interact with extracellular matrix and other neighboring cells. Cell-cell interactions, especially those between distinct phenotypes, have attracted particular interest due to the significant physiological relevance they can reveal for both fundamental and applied biomedical research. To study cell-cell interactions, it is necessary to develop co-culture systems, where different cell types can be cultured within the same confined space. Although the current advancement in lab-on-a-chip technology has allowed the creation of in vitro models to mimic the complexity of in vivo environment, it is still rather challenging to create such co-culture systems for easy control of different colonies of cells. In this paper, we have demonstrated a straightforward method for the development of an on-chip co-culture system. It involves a series of steps to selectively change the surface property for discriminative cell seeding and to induce cellular interaction in a co-culture region. Bone marrow stromal cells (HS5) and a liver tumor cell line (HuH7) have been used to demonstrate this co-culture model. The cell migration and cellular interaction have been analyzed using microscopy and biochemical assays. This co-culture system could be used as a disease model to obtain biological insight of pathological progression, as well as a tool to evaluate the efficacy of different drugs for pharmaceutical studies.     

Resignifying Alan Kurdi: news photographs,memes, and the ethics of embodied vulnerability

The Turkish photojournalist Nilüfer Demir’s photograph of the drowned refugee child Alan Kurdi attained worldwide recognition as a media spectacle, initially prompting humanitarian responses and political action, but later morphing into online memes and inciting public backlash as “war porn.” The author argues here that the ethical motivations of photojournalism and memes are oppositional with regard to their representations of embodied vulnerability. While photojournalistic depictions of vulnerable bodies are motivated by an ethics of care intended to generate empathy and progressive social change, memes disrupt those affective connotations through processes of mimicry and replication. By means of a comparative semiological analysis, this paper examines the way the sign system of Demir’s photograph was mutated into memes, radically changing the ethical connotations of the former. The differing ethical affordances of news photos versus memes, and their relationship, explain the reversal of the cosmopolitan humanitarianism initially sparked by the Alan Kurdi photograph and tell us more about the ethical frictions and contrapositions at work in the contemporary media environment.     

A biologically active constituent of withania somnifera (ashwagandha) with antistress activity

In Ayurvedic medicine,Withania somnifera (Ashwagandha) is well known for its anti-stress activity. A passive rat experimental model, where the animals are subjected to multiple stress of cold, hypoxia, restraint (C-H-R) has been developed to evaluate adaptogenic properties of various fractions of W. somnifera root extracts. We have carried out extraction of roots of W. somnifera with water and further isolated one of the active constituents called compound X and also tested its anti-stress activity in C-H-R model. The effect of administration of W. somnifera water suspension (360 mg/Kg bw) and compound X (20mg/Kg bw) on the fall and recovery of colonic temperature was noted. There was an increase of ≈38% and ≈54% in the time taken to attain T_rec 23°C by rats given a single dose of fresh aqueous suspension and biologically active constituent (Compound X) respectively, where as decrease in the recovery time to attain T_rec 37°C is ≈13% and ≈33% respectively, as compared to control group. It is clear that rats treated with the fresh aqueous suspension and compound X ofWithania somnifera, could withstand the multiple stress of C-H-R better than control group.     

Preservice Elementary Teachers’ Science Self-Efficacy Beliefs and Science Content Knowledge

Self-efficacy beliefs that relate to teachers’ motivation and performance have been an important area of concern for preservice teacher education. Research suggests high-quality science coursework has the potential to shape preservice teachers’ science self-efficacy beliefs. However, there are few studies examining the relationship between science self-efficacy beliefs and science content knowledge. The purpose of this mixed methods study is to investigate changes in preservice teachers’ science self-efficacy beliefs and science content knowledge and the relationship between the two variables as they co-evolve in a specialized science content course. Results from pre- and post-course administrations of the Science Teaching Efficacy Belief Instrument-B (Bleicher, 2004) and a physical science concept test along with semi-structured interviews, classroom observations and artifacts served as data sources for the study. The 18 participants belonged to three groups representing low, medium and high initial levels of self-efficacy beliefs. A repeated measures multivariate analysis of variance design was used to test the significance of differences between the pre- and post-surveys across time. Results indicated statistically significant gains in participants’ science self-efficacy beliefs and science conceptual understandings. Additionally, a positive moderate relationship between gains in science conceptual understandings and gains in personal science teaching efficacy beliefs was found. Qualitative analysis of the participants’ responses indicated positive shifts in their science teacher self-image and they credited their experiences in the course as sources of new levels of confidence to teach science. The study includes implications for preservice teacher education programs, science teacher education, and research.