Mating System and Reproductive Success of a Small Population of Polygamous Snowy Plovers

Volume: 98Start Page: 15End Page: 3

Residual Ligand Entropy in the Binding of <i>p</i>-Substituted Benzenesulfonamide Ligands to Bovine Carbonic Anhydrase II

In studies on the thermodynamics of ligand−protein interactions, it is often assumed that the configurational and conformational entropy of the ligand is zero in the bound state (i.e., the ligand is rigidly fixed in the binding pocket). However, there is little direct experimental evidence for this assumption, and in the case of binding of <i>p</i>-substituted benzenesulfonamide inhibitors to bovine carbonic anhydrase II (BCA II), the observed thermodynamic binding signature derived from isothermal titration calorimetry experiments leads indirectly to the conclusion that a considerable degree of residual entropy remains in the bound ligand. Specifically, the entropy of binding increases with glycine chain length <i>n</i>, and strong evidence exists that this thermodynamic signature is not driven by solvent reorganization. By use of heteronuclear ¹⁵N NMR relaxation measurements in a series (<i>n</i> = 1−6) of ¹⁵N-glycine-enriched ligands, we find that the observed thermodynamic binding signature cannot be explained by residual ligand dynamics in the bound state, but rather results from the indirect influence of ligand chain length on protein dynamics

Improving the efficiency and effectiveness of pragmatic clinical trials in older adults in the United States

Pragmatic clinical trials (PCTs) seek to improve the generalizability and increase the statistical power of traditional explanatory trials. They are a major tenet of comparative effectiveness research. While a powerful study design, PCTs have been limited by high cost, modest efficiency, and limited ability to fill relevant evidence gaps. Based on an American Reinvestment and Recovery Act (ARRA) supported meeting of national stakeholders, we propose several innovations and future research that could improve the efficiency and effectiveness of such studies focused in the U.S. Innovations discussed include optimizing the use of community based practices through partnership with Practice Based Research Networks (PBRNs), using information technology to simplify PCT subject recruitment, consent and randomization processes, and utilizing linkages to large administrative databases, such as Medicare, as a mechanism to capture outcomes and other important PCT variables with lower subject and research team burden. Testing and adaptation of such innovations to PCT are anticipated to improve the public health value of these increasingly important studies

Functional outcome of PFC Sigma fixed and rotating-platform total knee arthroplasty. A prospective randomised controlled trial

The aim of this study was to determine whether there is a difference in functional outcome between the PFC Sigma fixed-bearing and rotating-platform total knee replacement systems. One hundred twenty patients were randomised to receive either a fixed-bearing or rotating-platform PFC Sigma total knee replacement. Range of movement (ROM), Oxford knee score (OKS) and Knee Society score (KSS) were assessed independently before and one year after surgery. Weight-bearing X-rays were taken immediately and one year post surgery to determine the incidence of osteolysis and loosening. At a mean follow-up of 13.4 months there was no statistically significant difference in mean ROM, OKS and KSS between the two groups. There was no evidence of osteolysis or loosening in either of the groups and no revision for infection or implant failure. This study shows that there is no statistically significant difference in functional outcome between the two types of implants at short-term follow-up

Improving the efficiency and effectiveness of pragmatic clinical trials in older adults in the United States

Pragmatic clinical trials (PCTs) seek to improve the generalizability and increase the statistical power of traditional explanatory trials. They are a major tenet of comparative effectiveness research. While a powerful study design, PCTs have been limited by high cost, modest efficiency, and limited ability to fill relevant evidence gaps. Based on an American Reinvestment and Recovery Act (ARRA) supported meeting of national stakeholders, we propose several innovations and future research that could improve the efficiency and effectiveness of such studies focused in the U.S. Innovations discussed include optimizing the use of community based practices through partnership with Practice Based Research Networks (PBRNs), using information technology to simplify PCT subject recruitment, consent and randomization processes, and utilizing linkages to large administrative databases, such as Medicare, as a mechanism to capture outcomes and other important PCT variables with lower subject and research team burden. Testing and adaptation of such innovations to PCT are anticipated to improve the public health value of these increasingly important studies