A computational model for analysis of uncoupled NO synthase on nitric oxide and superoxide interaction in microcirculation

Nitric oxide (NO) produced by endothelial cells is a key component for blood-vessel dilation. Dilation is achieved through smooth muscle relaxation as a response to NO transport. Inhibition of this process occurs through the inactivation of NO by reactive oxygen species, especially superoxide (O2 -). NO and superoxide react quickly, forming peroxynitrite (ONOO-). Both superoxide and peroxynitrite apply oxidative stress on vascular tissue. Experimental studies investigating NO interactions are difficult since these reactions occur rapidly and over small distances. This study presents a computational model to describe the interactions of NO, superoxide, and peroxynitrite across an arteriole/venule pair. Based on principles of mass transport, and using knowledge of chemical concentrations and reaction rates, a mathematical model was developed to generate the concentration profiles for NO, O2 -, and ONOO-. We simulated excessive oxidative stress by uncoupled eNOS and determined its effect on NO concentration profiles throughout the region. Based on our understanding of the interactions involved, we predicted 1) increased oxidative stress in the venule decreases NO levels in regions of both the venule and neighboring arteriole, and 2) the amount of NO reduction will vary depending on the location of O2 - increase. The model demonstrates that different sources of O2 - have varied effects on NO concentration profiles, and excessive oxidative stress in the venule can impact NO levels in the venule as well as the arteriole. The results provide a more complete description of nitric oxide transfer, which is an important step toward understanding vascular complications in many pathological conditions

Monetary Intervention Mitigated Banking Panics During the Great Depression: Quasi-Experimental Evidence from the Federal Reserve District Border in Mississippi, 1929 to 1933

The Federal Reserve Act of 1913 divided Mississippi between the 6th (Atlanta) and 8th (St. Louis) Federal Reserve Districts. Before and during the Great Depression, these districts' policies differed. The Atlanta Fed championed monetary activism and the extension of credit to troubled banks. The St. Louis Fed adhered to the doctrine of real bills and eschewed expansionary initiatives. Outcomes differed across districts. In the 6th District, banks failed at lower rates than in the 8th District, particularly during the banking panic in the fall of 1930. The pattern suggests that discount lending reduced failure rates during periods of panic. Historical evidence and statistical analysis corroborates this conclusion.

Private experiments in global governance : primary commodity roundtables and the politics of deliberation

Emerging scholarship on global governance offers ever-more detailed analyses of private regulatory regimes. These regimes aim to regulate some area of social activity without a mandate from, or participation of, states or international organizations. While there are numerous empirical studies of these regimes, the normative theoretical literature has arguably struggled to keep pace with such developments. This is unfortunate, as the proliferation of private regulatory regimes raises important issues about legitimacy in global governance. The aim of this paper is to address some of these issues by elaborating a theoretical framework that can orientate normative investigation of these schemes. It does this through turning to the idea of experimentalist governance. It is argued that experimentalism can provide an important and provocative set of insights about the processes and logics of emerging governance schemes. The critical purchase of this theory is illustrated through an application to the case of primary commodities roundtables, part of ongoing attempts by NGOs, producers, and buyers to set sustainability criteria for commodity production across a range of sectors. The idea of experimentalist governance, we argue, can lend much needed theoretical structure to debates about the normative legitimacy of private regulatory regimes

Bonding Lexan and sapphire to form high-pressure, flame-resistant window

Flammable materials have been studied in normal gravity and microgravity for many years. Photography plays a major role in the study of the combustion process giving a permanent visual record that can be analyzed. When these studies are extended to manned spacecraft, safety becomes a primary concern. The need for a high-pressure, flame-resistant, shatter-resistant window permitting photographic recording of combustion experiments in manned spacecraft prompted the development of a method for bonding Lexan and sapphire. Materials that resist shattering (e.g., Lexan) are not compatible with combustion experiments; the material loses strength at combustion temperatures. Sapphire is compatible with combustion temperatures in oxygen-enriched atmospheres but is subject to shattering. Combining the two materials results in a shatter-resistant, flame-resistant window. Combustion in microgravity produces a low-visibility flame; however, flame propagation and flame characteristics are readily visible as long as there is no deterioration of the image. Since an air gap between the Lexan and the sapphire would reduce transmission, a method was developed for bonding these unlike materials to minimize light loss

Excellence in teaching and learning: A review of the literature for the Higher Education Academy

The Higher Education Academy commissioned a review of the literature on excellence in learning and teaching in higher education to enhance the higher education sector’s understanding of the varied conceptualisations and usages of the term ‘excellence’ and consider the implications for future policy and practice in relation to promoting and developing excellence. The literature searched included published research in the form of journal articles; books; reports from UK policy bodies and other agencies; as well as ‘grey’ literature. It covered conceptual studies, academic critiques and research studies on learning and teaching, as well as policy documents. Within a diverse and expanding system of higher education, such as in the UK, discourse on teaching and student learning highlights the tensions between different notions of excellence – for example, excellence as a positional good for students, as an aspirational target for continuous quality enhancement, as a form of reputational advantage for higher education institutions or as a means for achieving governmental economic and social goals. The review addressed questions of conceptualisations and usage at different (but interlinked) levels: system-wide; institutional; departmental; individual, and from two different perspectives, teaching and student learning