Modeling Collection Development Behavior

Most studies of collection development mask inadequate theoretical underpinnings with facile assumptions and dazzling statistical manipulations. This essay, in moving toward a model for collection development within both specific collections and library systems as a whole, seeks to demonstrate the full range and complexity of relevant factors. An enlarged theoretical grasp should help highlight both the possibilities and the challenges of existing approaches. One result could be a shift toward gaming or simulation techniques as more realistic analytical tools.     

Studies on homocysteine demonstrating its significance as a possible tool for differential diagnosis in occlusive vascular disease

Homocysteine (Hcy) is a non-protein forming amino-acid, whose metabolism is at the intersection of two metabolic pathways: remethylation and transsulfuration which are dependent on the vitamins folic acid, B₁₂ and B₆, and the enzymes methylenetetrahydrofolate reductase and cystathionine-β-synthetase. A deficiency of any of these vitamins or enzymes results in hyperhomocysteinemia. This causes oxidative and other damage to blood vessels, thus affecting various organ systems of the body. As part of our ongoing research on cardiovascular risk factors, we have studied the Hcy levels in the plasma of normal controls and those suffering from vascular diseases. It was observed that Hcy is significantly higher in patients of vascular diseases (21.59±1.28 μmol/L, mean±SEM), as compared to normal controls (11.33±0.18 μmol/L). This significance, was more pronounced in cases of venous thrombosis (26.77±2.43 μmol/L) as opposed to cases of arterial block (17.27±0.84 μmol/L). This signifies that Hcy estimation would be beneficial in obtaining a differential diagnosis in addition to being a modifiable vascular risk factor.