Developing a research framework for understanding the social realities, with special reference to Sri Lankan entrepreneurs

This paper identifies and examines issues of relevance for increasing effectiveness of entrepreneurial management research. These issues emerged from research into entrepreneurial behaviour and underlying motivations in Sri Lanka. Understanding of socially- and culturally-bound social actors, social actions and social outputs in entrepreneurial activity requires context-sensitivity, expressed through cognisance of institutional characteristics, the interface between cultural values and business, and historical and cultural forces which impact on entrepreneurship. We suggest that this requires exploration through bottom-up translations of actions consistent with the beliefs and values of the actors involved, employing qualitative methodology to ground the reality of human behaviour in deep-rooted cultural and social contexts. Thorough interpretation of holistic case studies that are capable of capturing the actors' viewpoints brings appropriate insights to the field of entrepreneurship

A power efficient delta-sigma ADC with series-bilinear switch capacitor voltage-controlled oscillator

In low-power VLSI design applications non-linearity and harmonics are a major dominant factor which affects the performance of the ADC. To avoid this, the new architecture of voltage-controlled oscillator (VCO) was required to solve the non-linearity issues and harmonic distortion. In this work, a 12-bit, 200MS/s low power delta-sigma analog to digital converter (ADC) VCO based quantizer was designed using switched capacitor technique. The proposed technique uses frequency to current conversion technique as a linearization method to reduce the non-linearity issue. Simulation result show that the proposed 12-bit delta-sigma ADC consumes the power of 2.68 mW and a total area of 0.09 mm² in 90 nm CMOS process

Isolation and proliferation of spermatogonial cells from ghezel sheep

Background: Sheep industry has taken steps toward transforming itself into a more efficient and competitive field. There are many varieties of sheep breeds in the world that each of them serves a useful purpose in the economies of different civilizations. Ghezel sheep is one of the Iranian important breeds that are raised for meat, milk and wool. Field of spermatogonial cell technologies provides tools for genetic improvement of sheep herd and multiple opportunities for research. Spermatogonial cells are the only stem cells capable of transmitting genetic information to future generations. Methods: This study was designed to extend the technique of isolation and in vitro proliferation of spermatogonial cells in Ghezel sheep. Results: Isolated cells were characterized further by using specific markers for type A spermatogonia, including PLZF. Also, sertoli cells were characterized by vimentin which is a specific marker for sertoli cells. After 10 days of co-culture, viability rates of the cells was above 94.7, but after the freezing process the viability rates were 74 percent. Conclusion: In this study, a standard method for isolation and in vitro proliferation of spermatogonial stem cells in Ghezel sheep was developed. © 2018, Avicenna Journal of Medical Biotechnology. All rights reserved

Isolation and proliferation of spermatogonial cells from ghezel sheep

Background: Sheep industry has taken steps toward transforming itself into a more efficient and competitive field. There are many varieties of sheep breeds in the world that each of them serves a useful purpose in the economies of different civilizations. Ghezel sheep is one of the Iranian important breeds that are raised for meat, milk and wool. Field of spermatogonial cell technologies provides tools for genetic improvement of sheep herd and multiple opportunities for research. Spermatogonial cells are the only stem cells capable of transmitting genetic information to future generations. Methods: This study was designed to extend the technique of isolation and in vitro proliferation of spermatogonial cells in Ghezel sheep. Results: Isolated cells were characterized further by using specific markers for type A spermatogonia, including PLZF. Also, sertoli cells were characterized by vimentin which is a specific marker for sertoli cells. After 10 days of co-culture, viability rates of the cells was above 94.7, but after the freezing process the viability rates were 74 percent. Conclusion: In this study, a standard method for isolation and in vitro proliferation of spermatogonial stem cells in Ghezel sheep was developed. © 2018, Avicenna Journal of Medical Biotechnology. All rights reserved

Nestin, a neuroectodermal stem cell marker, is expressed by bovine sertoli cells

Nestin, an intermediate filament protein is expressed by neuroectodermal stem cells and tumors originating from cells of neuroectodermal and mesenchymal lineages. Nestin expression is prominent in embryos and remains upregulated until 3-6 weeks after birth but is downregulated afterward. Sertoli cells are nucleated somatic cells that are spanned in the seminiferous epithelium and play a critical role in supporting and controlling germ-cell development. In this context, we employed immunocytochemical, Western blot, and Flow cytometric analyses to demonstrate nestin expression in bovine sertoli cells. Immunostaining clearly showed that setoli cells express high levels of nestin, a result which was confirmed by Western blot analysis of purified cells. Intracellular staining of sertoli cells by flow cytometry revealed that around 74 of the cells express this marker. Given the high expression of vimentin by sertoli cells, it is proposed that the expression of nestin in these cells might be required for the formation of stable vimentin/nestin intermediate filament network. In light of these findings, it seems that sertoli cells of mature bull have potentiality of proliferation. © 2010 Springer-Verlag London Limited

Influence of Nonpolio Enteroviruses and the Bacterial Gut Microbiota on Oral Poliovirus Vaccine Response: A Study from South India

BACKGROUND: Oral poliovirus vaccine (OPV) is less immunogenic in low- or middle-income than in high-income countries. We tested whether bacterial and viral components of the intestinal microbiota are associated with this phenomenon. METHODS: We assessed the prevalence of enteropathogens using TaqMan array cards 14 days before and at vaccination in 704 Indian infants (aged 6-11 months) receiving monovalent type 3 OPV (CTRI/2014/05/004588). Nonpolio enterovirus (NPEV) serotypes were identified by means of VP1 sequencing. In 120 infants, the prevaccination bacterial microbiota was characterized using 16S ribosomal RNA sequencing. RESULTS: We detected 56 NPEV serotypes on the day of vaccination. Concurrent NPEVs were associated with a reduction in OPV seroconversion, consistent across species (odds ratio [95% confidence interval], 0.57 [.36-.90], 0.61 [.43-.86], and 0.69 [.41-1.16] for species A, B, and C, respectively). Recently acquired enterovirus infections, detected at vaccination but not 14 days earlier, had a greater interfering effect on monovalent type 3 OPV seroresponse than did persistent infections, with enterovirus detected at both time points (seroconversion in 44 of 127 infants [35%] vs 63 of 129 [49%]; P = .02). The abundance of specific bacterial taxa did not differ significantly according to OPV response, although the microbiota was more diverse in nonresponders at the time of vaccination. CONCLUSION: Enteric viruses have a greater impact on OPV response than the bacterial microbiota, with recent enterovirus infections having a greater inhibitory effect than persistent infections