Segregation strategies for non-gm corn: Improving effectiveness through an analytical modeling approach

The open air growing environment for corn (Zea mays L.) makes it impossible to maintain genetic purity of 100%. Much debate has characterized the discussion on acceptable tolerance levels for adventitious presence to ensure coexistence between genetically modified and non-genetically modified crops. This research analyzes nine scenarios to test field, handling, and elevator-based segregation capabilities in a commodity system. Using stochastic models to model individual factors that contribute to adventitious presence in commodity maize including: impure seed, isolation distance, equipment cleanout, and elevator handling practices, Monte Carlo simulation was used to calculate the cumulative amount of adventitious presence for each scenario. Output values from 50,000 iterations for each scenario were used to assess the feasibility of meeting tolerance levels of 0.9%, 1.5%, and 3.0% genetic impurity. The modeling suggests that a 0.9% tolerance level is not feasible in most cases, with feasibility ranging from 0.0% to 49.8% across the nine scenarios. The tolerance levels of 1.5% and 3.0% are feasible in certain cases, however, with feasibility ranging from 3.0% to 94.7% at a tolerance level of 1.5% and feasibility ranging from 54.4% to 100.0% at a tolerance level of 3.0%. Sensitivity analysis found that isolation distance was the most significant factor in five out of the nine scenarios, elevator handling practices was most significant in three out of the nine scenarios, and seed purity was the most significant in one of the nine scenarios

Modular Hydraulic Test Bench

Our group is working to create a modular hydraulic test bench. This mobile bench will has improvements over current test benches through the use of a modular base frame and specifically design add-on features. Our mobile bench impliments several key design features including: a drip pan, forklift support, adjustable back wheels to provide improved center of gravity to reduce tipping hazard, a handle for ease of moving, and an adjustable drawer attachment

Segregation strategies for non-gm corn: Improving effectiveness through an analytical modeling approach

The open air growing environment for corn (Zea mays L.) makes it impossible to maintain genetic purity of 100%. Much debate has characterized the discussion on acceptable tolerance levels for adventitious presence to ensure coexistence between genetically modified and non-genetically modified crops. This research analyzes nine scenarios to test field, handling, and elevator-based segregation capabilities in a commodity system. Using stochastic models to model individual factors that contribute to adventitious presence in commodity maize including: impure seed, isolation distance, equipment cleanout, and elevator handling practices, Monte Carlo simulation was used to calculate the cumulative amount of adventitious presence for each scenario. Output values from 50,000 iterations for each scenario were used to assess the feasibility of meeting tolerance levels of 0.9%, 1.5%, and 3.0% genetic impurity. The modeling suggests that a 0.9% tolerance level is not feasible in most cases, with feasibility ranging from 0.0% to 49.8% across the nine scenarios. The tolerance levels of 1.5% and 3.0% are feasible in certain cases, however, with feasibility ranging from 3.0% to 94.7% at a tolerance level of 1.5% and feasibility ranging from 54.4% to 100.0% at a tolerance level of 3.0%. Sensitivity analysis found that isolation distance was the most significant factor in five out of the nine scenarios, elevator handling practices was most significant in three out of the nine scenarios, and seed purity was the most significant in one of the nine scenarios.</p

Modular Hydraulic Test Bench

Our group is working to create a modular hydraulic test bench. This mobile bench will has improvements over current test benches through the use of a modular base frame and specifically design add-on features. Our mobile bench impliments several key design features including: a drip pan, forklift support, adjustable back wheels to provide improved center of gravity to reduce tipping hazard, a handle for ease of moving, and an adjustable drawer attachment.</p

Modulation of cardiac Ca(V)1.2 channels by dihydropyridine and phosphatase inhibitor requires Ser-1142 in the domain III pore loop

Dihydropyridine-sensitive, voltage-activated calcium channels respond to membrane depolarization with two distinct modes of activity: short bursts of very short openings (mode 1) or repetitive openings of much longer duration (mode 2). Here we show that both the dihydropyridine, BayK8644 (BayK), and the inhibitor of Ser/Thr protein phosphatases, okadaic acid, have identical effects on the gating of the recombinant cardiac calcium channel, Ca(V)1.2 (α(1)C). Each produced identical mode 2 gating in cell-attached patches, and each prevented rundown of channel activity when the membrane patch was excised into ATP-free solutions. These effects required Ser or Thr at position 1142 in the domain III pore loop between transmembrane segments S5 and S6, where dihydropyridines bind to the channel. Mutation of Ser-1142 to Ala or Cys produced channels with very low activity that could not be modulated by either BayK or okadaic acid. A molecular model of Ca(V)1.2 indicates that Ser-1142 is unlikely to be phosphorylated, and thus we conclude that BayK binding stabilizes mode 2 gating allosterically by either protecting a phospho Ser/Thr on the α(1)C subunit or mimicking phosphorylation at that site

Recent advances in the molecular understanding of voltage gated Ca2+ channels

Original article can be found at: http://www.sciencedirect.com/science/journal/10447431 Copyright Elsevier Inc. DOI: 10.1006/mcne.1999.0795 [Full text of this article is not available in the UHRA]It has long been recognized that the activity of voltage-sensitive Ca21 channels (VSCCs) is central to the function of all excitable cells (i.e., cells that fire action potentials), as well as many nonexcitable cells (Hille, 1992). VSCCs provide a crucial link between a cell’s membrane potential and the enormous number of intracellular processes that either directly utilize elevations of [Ca21]i as a functional trigger (e.g., exocytosis, muscle contraction) or are modulated by Ca21-dependent signalling cascades (e.g., gene expression, cell division) (Catterall, 1995; Bito et al., 1997; Morgan and Curran, 1988; Tanabe et al., 1993; Dunlap et al., 1995).Peer reviewe