Cultural factors related to the peer review of teaching

Since 1994, the American Association for Higher Education Peer Review of Teaching Project has sought to popularize the notion that teaching is both a scholarly activity and community property to be shared with and critiqued by the larger academic community. In order to accomplish these goals, each of the three academic units at the twelve participating universities developed a pilot project that conformed to its own institutional, academic unit, and disciplinary culture. At a large Midwestern university, the academic units of mathematics, history, and nursing developed different projects. Each of these projects took account of the unit's specific culture, and this fact helps to account, in large part, for each project's success.     

Supporting constant-bit-rate-encoded MPEG-2 transport over local ATM networks

As one of the fast-developing switch-based high-speed networks, asynchronous transfer mode (ATM) is a promising network standard which may satisfy various requirements of multimedia computing. The Moving Picture Experts Group (MPEG) standard was designed to support full motion video stored on digital storage media at compression ratios up to 200:1. MPEG-2 is the second development phase of the MPEG standard and is designed for higher resolutions (including but not restricted to interlaced video) and higher bit rates (up to 20 Mbits/s). In this paper, the ATM adaptation layer type 5 (AAL-5) protocol was used to encapsulate constant-bit-rate-encoded MPEG-2 transport packets because of AAL-5's general availability. However, there is a mismatch of size between MPEG-2's transport packets (188 bytes) and ATM AAL-5's protocol data units (up to 65 535 bytes). In this paper, we examine and analyze four different packing schemes, 1TP, 2TP, nTP-Tight, and nTP-Loose (the scheme we propose), which encapsulated a certain number of MPEG-2 transport packets into one AAL-5 PDU. nTP-Loose scheme is proposed to have (1) better end-to-end performance than schemes 1TP and 2TP, (2) better error-recovery capability than scheme nTP-Tight, and (3) the same buffer requirement as scheme 2TP. A Power Macintosh ATM platform was used to identify the range of possible ways of packing MPEG-2 transport packets into one ATM AAL-5 PDU, when schemes with more than two MPEG-2 transport packets are chosen. Based on the test results, 10 or 12 MPEG-2 transport packets, which can yield throughputs of 70.36 and 78.98 Mbits/s, respectively, are recommended. Fast forward and backward playing of MPEG-2 movies (several times the video display speed) can be easily achieved via ATM networks.     

Comparison of left anterior oblique, anterior, and geometric mean methods in gastric emptying assessment of postpancreaticoduodenectomy patients

Although left anterior oblique (LAO) gastric emptying studies appear to be an adequate alternative to geometric mean (GM) measurements in patients with normal gastric anatomy, it is not clear whether they can be used after gastric or duodenal surgery. In this study, dual-phase gastric emptying studies with combined solid-liquid meal were performed in 54 patients who had undergone pancreaticoduodenectomy (Whipple procedure). Gastric emptying was studied with GM, LAO, and anterior (ANT) methods. T1/2 and percent gastric retention at 10, 30, 60, 90, and 120 minutes were calculated. Results from the three methods were compared using correlation analysis and the t test. The t test showed no significant difference in T1/2 and percent retention values between the GM and LAO or ANT views. The solid emptying T1/2 showed a better correlation between GM and LAO values (r = 0.824) than between GM and ANT (r = 0.589). For the liquid T1/2, the reverse was true. Correlation between GM and ANT (r = 0.939) was better than between GM and LAO (r = 0.839); however, both LAO and ANT views correlated well with GM liquid emptying. It is concluded that the LAO view can replace GM gastric emptying methods in postpancreaticoduodenectomy patients for evaluation of both solid and liquid emptying, although the ANT view appears completely adequate for the study of liquid emptying.     

MR angiography of the spine

Postcontrast MR angiography complements the standard spinal MR imaging study by improving detection and display of normal and abnormal intradural vessels, primarily veins. Detection of abnormal veins facilitates diagnosis of spinal vascular malformations and vascular tumors. The most useful application has been in screening for spinal dural arteriovenous fistula, in which MR angiography demonstrates the medullary vein into which the fistula drains, thus allowing noninvasive identification of the spinal level of the fistula.     

Pin force measurement in a halo-vest orthosis, in vivo

Salmon calcitonin (sCT) is an example of one of the many bioactive peptides that require amidation of the carboxy terminus for full potency. We describe a method for the production of amidated sCT in the mammary gland of transgenic rabbits. Expression of a fusion protein comprising human alpha lactalbumin joined by an enterokinase cleavable linker to sCT was directed to the mammary gland under the control of the ovine beta lactoglobulin promoter. C-terminal amidation in vivo was achieved by extending the sCT by a single glycine residue that provides a substrate for endogenous amidating activity in the mammary gland. Full characterization of the released sCT demonstrated it to be equivalent to synthetic standard in terms of structure, purity, and potency.     

Reactivity of gemfibrozil 1-o-beta-acyl glucuronide. Pharmacokinetics of covalently bound gemfibrozil-protein adducts in rats

Acyl glucuronides are electrophilic metabolites that are readily hydrolyzed, undergo intramolecular rearrangement, and mediate the covalent binding of many acidic drugs to endogenous proteins. Gemfibrozil is extensively metabolized to gemfibrozil acyl glucuronide in humans and rats. The aims of this study were to demonstrate the reactivity of gemfibrozil glucuronide, determine whether gemfibrozil formed covalently bound protein adducts in vivo, describe the pharmacokinetics of adduct formation, and examine the role of gemfibrozil glucuronide in adduct formation. Rats were administered 150 mg/kg gemfibrozil daily for up to 37 days and killed 1, 2, 5, 10, 19, and 37 days after commencement of dosing, and 1, 2, 3, 8, 17, and 30 days after cessation of dosing. Plasma, liver, kidney, and heart were examined for adduct formation. Plasma was quantitatively the most important site for formation of gemfibrozil-protein adducts with mean (SE) steady-state concentrations of 31.40 (2.40) ng/mg protein attained by approximately the 10th day of dosing. Adduct half-life in plasma was 3.1 days, consistent with the elimination half-life of albumin. Mean (SE) kidney, liver, and heart steady-state adduct concentrations were 2.13 (0.11), 0.89 (0.35), and 0.95 (0.07) ng/mg protein, respectively. The rate of gemfibrozil-protein adduct accumulation seemed greatest in liver, but was similar in kidney and plasma, with approximately 2x, 16x, and 30x accumulation, respectively, over the dosing interval. In all tissues, adduct half-lives were significantly greater than those of the noncovalently bound gemfibrozil or gemfibrozil glucuronide.(ABSTRACT TRUNCATED AT 250 WORDS)