The Widget Effect: Our National Failure to Acknowledge and Act on Differences in Teacher Effectiveness

Examines flaws in evaluations of teacher effectiveness that lead districts to allow poor performance to go unaddressed. Recommends a comprehensive system, to be used accountably and integrated with human capital policies, and efficient dismissal policies

Lessons Learned in the Flight Qualification of the S-NPP and NOAA-20 Solar Array Mechanisms

Deployable solar arrays are the energy source used on almost all Earth orbiting spacecraft and their release and deployment are mission-critical; fully testing them on the ground is a challenging endeavor. The 8 meter long deployable arrays flown on two sequential NASA weather satellites were each comprised of three rigid panels almost 2 meters wide. These large panels were deployed by hinges comprised of stacked constant force springs, eddy current dampers, and were restrained through launch by a set of four releasable hold-downs using shape memory alloy release devices. The ground qualification testing of such unwieldy deployable solar arrays, whose design was optimized for orbital operations, proved to be quite challenging and provides numerous lessons learned. A paperwork review and follow-up inspection after hardware storage determined that there were negative torque margins and missing lubricant, this paper will explain how these unexpected issues were overcome. The paper will also provide details on how the hinge subassemblies, the fully-assembled array, and mechanical ground support equipment were subsequently improved and qualified for a follow-on flight with considerably less difficulty. The solar arrays built by Ball Aerospace Corp. for the Suomi National Polar Partnership (S-NPP) satellite and the Joint Polar Satellite System (JPSS-1) satellite (now NOAA-20) were both successfully deployed on-obit and are performing well

Short range RF communication for jet engine control

A method transmitting a message over at least one of a plurality of radio frequency (RF) channels of an RF communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of RF channels. The characteristics of the jamming pulses in the at least one of the plurality of RF channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of RF channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses

Some aspects of glutathione and L-arginine/nitric oxide metabolism in the maintenance of platelet function.

Evidence is presented here for the regulation of platelet activation by intra-platelet levels of glutathione (GSH) and L-arginine. Our data is consistent with the intra-platelet GSH ((GSH) \sb{\rm ip}) modulation through the regulation of the thromboxane A\sb2 (TxA\sb2) biosynthesis. The reduction of (GSH) \sb{\rm ip} by 100 $\mu$M 1-chloro-2,4-dinitrobenzene (CDNB) enhanced thrombin-induced platelet aggregation and ADP-induced platelet aggregation was inhibited by the elevation of (GSH) \sb{\rm ip} through a facilitative GSH-specific transport system. Platelet facilitative GSH uptake was subsequently characterized as being Na\sp+-independent, concentration dependent (K\sb{\rm M} and V\sb{\rm max} for GSH uptake in platelet plasma membrane vesicles (PPMV) is $18.2 \pm 3.6\ \mu$M and 178 $\pm$ 27 pmol/min/mg protein, respectively), inhibited by GSH analogs, enhanced by KCl-induced membrane depolarization and sensitive to the intraplatelet thiol redox status since the K\sb{\rm M} and V\sb{\rm max} for GSH uptake in intact platelets changed from 137 $\mu$M and 42.2 pmol/min/10\sp9 platelets, respectively, to 31.7 $\mu$M and 31.3 pmol/min/10\sp9 platelets, respectively, on reducing intra-platelet GSH with 100 $\mu$M CDNB. Glutathione reductase (GR) was found to be inhibited by physiological levels of GSH with species-dependent differences. With respect to varying GSSG, GSH inhibited GR from human platelets in an apparent uncompetitive manner (K\sb{\rm i} = 6.6 mM), while bovine intestinal mucosa and yeast GRs displayed apparent mixed hyperbolic inhibition (K\sb{\rm i} = 2.9 and 2.4 mM, respectively), and the E. coli enzyme exhibited an apparent, competitive inhibition (K\sb{\rm i} = 12.1 mM). In the course of this study it was observed that 1-(4-chlorophenyl)-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide (CDDP) is an alpha class selective glutathione S-transferase (GST) substrate and that certain analogs of CDDP are GST inhibitors with K\sb{\rm i}s ranging from 7.5 to 53.4 $\mu$M. Exogenous L-arginine inhibited ADP-induced platelet aggregation which suggests that platelet-derived NO regulates platelet activation. Platelet L-arginine uptake was via the cationic amino acid transporter, system y\sp+, which appears to be regulated by NO. S-nitrosoglutathione (GSNO) was found to be photolyzed by visible light. The release of NO by GSNO photolysis resulted in an enhanced NO-dependent cytotoxicity towards HL-60 cells. GSNO, or related compounds, may therefore find use as photochemotherapeutic agents.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .S49. Source: Dissertation Abstracts International, Volume: 56-11, Section: B, page: 6097. Adviser: Bulent Mutus. Thesis (Ph.D.)--University of Windsor (Canada), 1995

Assembly and Disassembly of DNA Polymerase Holoenzyme

The complex task of genomic replication requires a large collection of proteins properly assembled within the close confines of the replication fork. The mechanism and dynamics of holoenzyme assembly and disassembly have been investigated using steady state and pre-steady state methods as opposed to structural studies, primarily due to the intrinsic transient nature of these protein complexes during DNA replication. The key step in bacteriophage T4 holoenzyme assembly involves ATP hydrolysis, whereas disassembly is mediated by subunit dissociation of the clamp protein in an ATP-independent manner

Assembly and Disassembly of DNA Polymerase Holoenzyme

The complex task of genomic replication requires a large collection of proteins properly assembled within the close confines of the replication fork. The mechanism and dynamics of holoenzyme assembly and disassembly have been investigated using steady state and pre-steady state methods as opposed to structural studies, primarily due to the intrinsic transient nature of these protein complexes during DNA replication. The key step in bacteriophage T4 holoenzyme assembly involves ATP hydrolysis, whereas disassembly is mediated by subunit dissociation of the clamp protein in an ATP-independent manner

Philanthropic Capital for Communities: A Comparative Analysis of Community Foundation and United Way Grantmaking

This report provides an analysis of grants made by 1,650 community foundations and local United Ways--accounting for over $20 billion between 2012 and 2016.C.S. Mott Foundation Community Philanthrop

Protein-Protein and Protein-DNA Interactions at The Bacteriophage T4 DNA Replication Fork. Characterization of a Fluorescently Labeled DNA Polymerase Sliding Clamp

The T4 DNA polymerase holoenzyme is composed of the polymerase enzyme complexed to the sliding clamp (the 45 protein), which is loaded onto DNA by an ATP-dependent clamp loader (the 44/62 complex). This paper describes a new method to directly investigate the mechanism of holoenzyme assembly using a fluorescently labeled cysteine mutant of the 45 protein. This protein possessed unaltered function yet produced substantial changes in probe fluorescence intensity upon interacting with other components of the holoenzyme. These fluorescence changes provide insight into the role of ATP hydrolysis in holoenzyme assembly. Using either ATP or the non-hydrolyzable ATP analog, adenosine 5′-O-(3-thiophosphate), events in holoenzyme assembly were assigned as either dependent or independent of ATP hydrolysis. A holoenzyme assembly mechanism is proposed in which the 44/62 complex mediates the association of the 45 protein with DNA in an ATP-dependent manner not requiring ATP hydrolysis. Upon ATP hydrolysis, the 44/62 complex triggers a conformational change in the 45 protein that may be attributed to the clamp loading onto DNA