Case Selection: A Case for a New Approach

While conducting empirical research regarding the relationship between case characteristics and student performance, the authors were surprised to find a lack of conceptual and empirical research regarding instructor case selection. This conceptual paper explores the case selection process and introduces case selection as an under-investigated component of the case teaching method in management education. Case selection is important because it is a critical component of the case teaching method. There has been no empirical testing of the effectiveness of case selection technique. The authors identify and propose case selection criteria for instructors of management education

Chromosomal mapping of murine c-fes and c-src genes

The murine homologs of two viral oncogenes associated with tyrosine-specific kinase activity have been assigned to different loci in the mouse genome. The segregation of restriction site polymorphisms, as detected by probes that are specific for endogenous c-fes and c-src sequences, was followed in the DNA of recombinant inbred strains. The c-fes gene was mapped to the proximal portion of chromosome 7, very close to the Gpi-1 locus, whereas c-src was linked to the Psp locus on the distal half of chromosome 2

MaizeGDB's new data types, resources and activities

MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecular markers, references and contact information for maize researchers worldwide. Also available through MaizeGDB are various community support service bulletin boards including the Editorial Board's list of high-impact papers, information about the Annual Maize Genetics Conference and the Jobs board where employment opportunities are posted. Reported here are data updates, improvements to interfaces and changes to standard operating procedures that have been made during the past 2 years. MaizeGDB is freely available and can be accessed online at

Cellular metabolism as a basis for immune privilege

We hypothesize that the energy strategy of a cell is a key factor for determining how, or if, the immune system interacts with that cell. Cells have a limited number of metabolic states, in part, depending on the type of fuels the cell consumes. Cellular fuels include glucose (carbohydrates), lipids (fats), and proteins. We propose that the cell's ability to switch to, and efficiently use, fat for fuel confers immune privilege. Additionally, because uncoupling proteins are involved in the fat burning process and reportedly in protection from free radicals, we hypothesize that uncoupling proteins play an important role in immune privilege. Thus, changes in metabolism (caused by oxidative stresses, fuel availability, age, hormones, radiation, or drugs) will dictate and initiate changes in immune recognition and in the nature of the immune response. This has profound implications for controlling the symptoms of autoimmune diseases, for preventing graft rejection, and for targeting tumor cells for destruction

Experimental demonstration of 72% reach enhancement of 3.6Tbps optical transmission system using mid-link Optical Phase Conjugation

We experimentally demonstrate nonlinear noise compensation in optical phase conjugation assisted 1st order Raman amplified 30x30Gbaud DP-QPSK transmission system with a spectral efficiency of 3.6b/s/Hz. We show that by optimizing the link symmetry, even with only 1st order Raman amplification a single, mid-link, optical phase conjugation compensates for 90% off the signal-signal nonlinear interference resulting in a 2.3dB performance enhancement. We show that increasing the number of optical phase conjugation s in the presence of 10% residual nonlinearity results in a reduction in the performance enhancement owing to an enhancement in the nonlinear noise generation efficiency of the system. We achieve a record 72% optical phase conjugation enabled reach enhancement of the 30x30Gbaud DP-QPSK signals

Parallel variation of mass transport and heterogeneous and homogeneous electron transfer rates in hybrid redox polyether molten salts

Metal complexes can be prepared as highly viscous (semisolid), room temperature molten salts by combining them with oligomeric polyether substituents. The fluidity and transport properties of these hybrid redox polyether melts can be systematically manipulated by changing the oligomeric chain lengths and by adding unattached oligomers as plasticizers. This paper describes the voltammetrically measured transport properties of several Co(II) polypyridine (2,2‘-bipyridine, phenanthroline) melts. The properties evaluated are the physical self-diffusion coefficient (DPHYS) of the cationic complex in its melt, the diffusivity of its counterion (DCION), the heterogeneous electron-transfer rate constant (kHET) of the Co(III/II) oxidation at the electrode surface, and the rate constant (kEX) for homogeneous electron self-exchange between Co(II) and Co(I) in the mixed valent layer next to the electrode. These dynamics parameters change in parallel manners, over a large (\u3e103) range of values, when the melt fluidity is changed by plasticizers or temperature. While kHET and kEX both change systematically with DPHYS, they change on a more nearly proportional basis with DCION. The latter relationship is interpreted as a kind of solvent dynamics control in which both the homogeneous Co(II/I) and heterogeneous Co(III/II) reaction rates are controlled by the ionic atmosphere relaxation time constant, namely, the time constant of redistribution of counterions following an electron-transfer step that has produced a nonequilibrium charge distribution. DCION provides a measure of the ion atmosphere relaxation rate

Elemental concentrations in the seed of mutants and natural variants of Arabidopsis thaliana grown under varying soil conditions

Peer reviewedPublisher PD

Ion atmosphere relaxation controlled electron transfers in cobaltocenium polyether molten salts

A room-temperature redox molten salt for the study of electron transfers in semisolid media, based on combining bis(cyclopentadienyl)cobalt with oligomeric polyether counterions, [Cp2Co](MePEG350SO3), is reported. The transport properties of the new molten salt can be varied (plasticized) by varying the polyether content. The charge transport rate during voltammetric reduction of the ionically conductive [Cp2Co](MePEG350SO3) molten salt exceeds the actual physical diffusivity of [Cp2Co]+ because of rapid [Cp2Co]+/0 electron self-exchanges. The measured [Cp2Co]+/0 electron self-exchange rate constants (kEX) are proportional to the diffusion coefficients (DCION) of the counterions in the melt. The electron-transfer activation barrier energies are also close to those of ionic diffusion but are larger than those derived from optical intervalent charge-transfer results. Additionally, the [Cp2Co]+/0 rate constant results are close to those of dissimilar redox moieties in molten salts where DCION values are similar. All of these characteristics are consistent with the rates of electron transfers of [Cp2Co]+/0 (and the other donor−acceptor pairs) being controlled not by the intrinsic electron-transfer rates but by the rate of relaxation of the ion atmosphere around the reacting pair. In the low driving force regime of mixed-valent concentration gradients, the ion atmosphere relaxation is competitive with electron transfer. The results support the generality of the recently proposed model of ionic atmosphere relaxation control of electron transfers in ionically conductive, semisolid materials

Orion Portable Fire Extinguisher Performance Testing Against a Laptop Lithium-Ion Battery Stored-Energy Fire-Method, Magnesium Fires, and Combustion By-Product Toxicity

As part of the qualification of the International Space Station (ISS) fine water mist portable fire extinguisher (PFE), several test methods were developed to determine firefighting capability against stored-energy sources. The most challenging of these devised stored-energy fire test methods proved to be the Lithium-ion (Li-ion) battery fire test scenario. The Orion crew capsule will utilize a different PFE technology from ISS (water spray rather than water mist), which spurred the need for the same type of evaluation focused on the sources of stored energy slated for use on Orion. Laptops were identified as a realistic source for stored-energy fires, requiring a modified Li-ion battery fire test scenario. In addition to open test cell (ambient oxygen concentration) testing to evaluate new proposed PFE performance, sealed chamber (20.9% and elevated oxygen concentration) testing was also performed. Chamber testing included combustion product sampling at various fire progression points for analysis and application to Orion emergency equipment design and response planning. The PFE stored-energy fire test methodology was modified and testing performed. Initial tests indicated ignition of the laptop magnesium laptop cases was possible. Additional tests were performed to characterize the laptop magnesium case fire behavior in various configurations. The new water spray PFE technology proved effective in extinguishing laptop stored-energy fires, and much was learned in the way these types of fires progressed. Findings indicate potential laptop magnesium case ignition mitigation strategies need to be further investigated

Natural Genetic Variation in Selected Populations of Arabidopsis thaliana Is Associated with Ionomic Differences

Controlling elemental composition is critical for plant growth and development as well as the nutrition of humans who utilize plants for food. Uncovering the genetic architecture underlying mineral ion homeostasis in plants is a critical first step towards understanding the biochemical networks that regulate a plant's elemental composition (ionome). Natural accessions of Arabidopsis thaliana provide a rich source of genetic diversity that leads to phenotypic differences. We analyzed the concentrations of 17 different elements in 12 A. thaliana accessions and three recombinant inbred line (RIL) populations grown in several different environments using high-throughput inductively coupled plasma- mass spectroscopy (ICP-MS). Significant differences were detected between the accessions for most elements and we identified over a hundred QTLs for elemental accumulation in the RIL populations. Altering the environment the plants were grown in had a strong effect on the correlations between different elements and the QTLs controlling elemental accumulation. All ionomic data presented is publicly available at www.ionomicshub.org