The haematopoietic stem cell niche:new insights into the mechanisms regulating haematopoietic stem cell behaviour

The concept of the haematopoietic stem cell (HSC) niche was formulated by Schofield in the 1970s, as a region within the bone marrow containing functional cell types that can maintain HSC potency throughout life. Since then, ongoing research has identified numerous cell types and a plethora of signals that not only maintain HSCs, but also dictate their behaviour with respect to homeostatic requirements and exogenous stresses. It has been proposed that there are endosteal and vascular niches within the bone marrow, which are thought to regulate different HSC populations. However, recent data depicts a more complicated picture, with functional crosstalk between cells in these two regions. In this review, recent research into the endosteal/vascular cell types and signals regulating HSC behaviour are considered, together with the possibility of a single subcompartmentalised niche.

Corporate governance and accounting conservatism:evidence from the banking industry

Research Question/Issue: In this paper, we empirically investigate whether US listed commercial banks with effective corporate governance structures engage in higher levels of conservative financial accounting and reporting. Research Findings/Insights: Using both market- and accrual-based measures of conservatism and both composite and disaggregated governance indices, we document convincing evidence that well-governed banks engage in significantly higher levels of conditional conservatism in their financial reporting practices. For example, we find that banks with effective governance structures, particularly those with effective board and audit governance structures, recognize loan loss provisions that are larger relative to changes in nonperforming loans compared to their counterparts with ineffective governance structures. Theoretical/Academic Implications: We contribute to the extant literature on the relationship between corporate governance and quality of accounting information by providing evidence that banks with effective governance structures practice higher levels of accounting conservatism. Practitioner/Policy Implications: The findings of this study would be useful to US bank regulators/supervisors in improving the existing regulatory framework by focusing on accounting conservatism as a complement to corporate governance in mitigating the opaqueness and intense information asymmetry that plague banks.