Predicting seed germination of winterfat (Eurotia lanata), a native forage species

Non-Peer ReviewedThe timing of seed germination plays a critical role in the survival of plants in natural ecosystems. Population-based models for the prediction of seed germination as the function of temperature and water potential have been developed, which can also be used in predicting field emergence. We used winterfat (Eurotia lanata) to test variations in parameters of the thermal time and hydrothermal time model among seed mass classes and germination conditions. Germination rates (GR) of subpopulations were estimated from germination time courses over a water potential range from 0 to –1.33 MPa at 2, 5, 10, 15, 20, and 25 oC. Estimated base temperature (Tb) was lower in the large seed mass class (-4.5 oC) than the small seed mass class (-3.5 oC). The ζ b(50) was lowest at intermediate temperatures between 10 to 15 oC. A linear increase of hydro time (ρH) with subpopulation was found at lower temperatures, especially at 2 oC. There were no significant differences in ζ b(50) between large and small seeds, but significant differences were observed in hydrothermal time requirement (ρHT(50)), which was lower at intermediate temperatures than at either lower or higher temperatures. The predictability of the thermal and hydrothermal time model was improved when parameters were allowed to change with seed size and germination conditions. Variations in Tb among seed mass classes favor large seeds, which accumulate more thermal time at a given temperature. This is particularly important for species such as winterfat, which germinates early in the season and early-emerged seedlings have better chance to establish and survive

Laboratory investigation of lateral dispersion within dense arrays of randomly distributed cylinders at transitional Reynolds number

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Evidence for Modification of the Electronic Density-of-States by Zero-Point Lattice Motion in One-Dimension - Luminescence and Resonance Raman Studies of An Mx Solid

Luminescence spectra, both emission and excitation, and the excitation dependence of the resonance Raman spectra, have been measured for the quasi-one-dimensional charge-density-wave material [Pt(en)2][Pt(en)2Cl2](ClO4)4, en = 1,2-diaminoethane. While the luminescence experiments show the existence of tail states at low temperature in the band gap region, the Raman measurements conclusively demonstrate that this tail does not arise from ordinary static structural disorder. These results can be explained by considering the zero-point motion of the lattice

Pressure Tuning of the Charge Density Wave in the Halogen-Bridged Transition-Metal (MX) Solid Pt2Br6(NH3)4Pt_2Br_6(NH_3)_4

We report the pressure dependence up to 95 kbar of Raman active stretching modes in the quasi-one-dimensional MX chain solid $Pt_2Br_6(NH_3)_4$. The data indicate that a predicted pressure-induced insulator-to-metal transition does not occur, but are consistent with the solid undergoing either a three-dimensional structural distortion, or a transition from a charge-density wave to another broken-symmetry ground state. We show that such a transition cacan be well-modeled within a Peierls-Hubbard Hamiltonian. 1993 PACS: 71.30.+h, 71.45.Lr, 75.30.Fv, 78.30.-j, 81.40.VwComment: 4 pages, ReVTeX 3.0, figures available from the authors on request (Gary Kanner, [email protected]), to be published in Phys Rev B Rapid Commun, REVISION: minor typos corrected, LA-UR-94-246

Exchange flow between open water and floating vegetation

This study describes the exchange flow between a region with open water and a region with a partial-depth porous obstruction, which represents the thermally-driven exchange that occurs between open water and floating vegetation. The partial-depth porous obstruction represents the root layer, which does not penetrate to the bed. Initially, a vertical wall separates the two regions, with fluid of higher density in the obstructed region and fluid of lower density in the open region. This density difference represents the influence of differential solar heating due to shading by the vegetation. For a range of root density and root depths, the velocity distribution is measured in the lab using PIV. When the vertical wall is removed, the less dense water flows into the obstructed region at the surface. This surface flow bifurcates into two layers, one flowing directly through the root layer and one flowing beneath the root layer. A flow directed out of the vegetated region occurs at the bed. A model is developed that predicts the flow rates within each layer based on energy considerations. The experiments and model together suggest that at time- and length-scales relevant to the field, the flow structure for any root layer porosity approaches that of a fully blocked layer, for which the exchange flow occurs only beneath the root layer.National Science Foundation (U.S.) (grant EAR0509658

Set optimization - a rather short introduction

Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems

Analysis of the symmetry of electrodes for Electropalatography with Cone Beam CT Scanning

The process of compression of air and vibration of activity in the larynx through which speech is produced is of great interest in phonetics, phonology, psychology and is related to various areas of biomedical engineering as it has a strong relationship with cochlear implants, Parkinson’s disease and Stroke. One technique by means of which speech production is analysed is the use of electropalatography, in which an artificial palate, moulded to the speakers’ hard palate is introduced in the mouth. The palate contains a series of electrodes, which monitor contact between the tongue and the palate during speech production. There is interest in the symmetry or asymmetry of the movement of the tongue as this may be related to languages or right- or left-handedness, however this has never been thoroughly studied. A specific limitation of electropalatography for symmetry studies is that palates are hand-crafted and the position of the electrodes themselves may be asymmetric. In this work, we analyse the positioning of electrodes of one electropalatography setting. The symmetry was analysed by locating the electrodes of the palate through the observation of the palate with Computed Tomography. An algorithm to segment the electrodes and find the symmetry of left and right sides of the palates is described. No significant asymmetry was found for one specific palate. The methodology presented should allow the analysis of palates to be used in larger studies of speech production

Feasibility of the porous zone approach to modelling vegetation in CFD

Vegetation within stormwater ponds varies seasonly and its presence affects the flow field, which in turn affects the pond’s Residence Time Distribution and its effectiveness at pollutant removal. Vegetated flows are complex and, as a result, few suitable tools exist for evaluating realistic stormwater pond designs. Recent research has suggested using a porous zone to represent vegetation within a CFD model, and this paper investigates the feasibility of this approach using ANSYS Fluent. One of the main benefits of using a porous zone is the ability to derive the relevant parameters from the known physical characteristics of stem diameter and porosity using the Ergun equation. A sensitivity analysis on the viscous resistance factor 1/α1/α and the inertial resistance factor C2C2 has been undertaken by comparing model results to data collected from an experimental vegetated channel. Best fit values of C2C2 were obtained for a range of flow conditions including emergent and submerged vegetation. Results show the CFD model to be insensitive to 1/α1/α but very sensitive to values of C2C2. For submerged vegetation, values of C2C2 derived from the Ergun equation are under-predictions of best-fit C2C2 values as only the turbulence due to the shear layer is represented. The porous zone approach does not take into account turbulence generated from stem wakes such that no meaningful predictions for emergent vegetation were obtained. C2C2 values calculated using a force balance show better agreement with best-fit C2C2 values than those derived from the Ergun equation. Manually fixing values of kk and εε within the porous zone of the model shows initial promise as a means of taking stem wakes into account

Estimating unknown values in reciprocal intuitionistic preference relations via asymmetric fuzzy preference relations

Intuitionistic preference relations are becoming increasingly important in the field of group decision making since they present a flexible and simple way to the experts to provide their preference relations, while at the same time allowing them to accommodate a certain degree of hesitation inherent to all decision making processes. In this contribution, we prove the mathematical equivalence between the set of asymmetric fuzzy preference relations and the set of reciprocal intuitionistic fuzzy preference relations. This result is exploited to tackle the presence of incomplete reciprocal intuitionistic fuzzy preference relation in decision making by developing a consistency driven estimation procedure via the corresponding equivalent incomplete asymmetric fuzzy preference relation

The study of expanded tri-lobed flap in a rabbit model: possible flap model in ear reconstruction?

BACKGROUND: Local flaps are widely used in reconstructive surgery. Tri-lobed skin flap is a relatively new flap and there has been no experimental model of this flap. This flap can be used for repair of full thickness defects in the face, ears and alar region. Based on the size of ears in a rabbit, we designed a model of ear reconstruction using expanded tri-lobed flap. Local flaps are more advantageous in that they provide excellent color and texture matching up with those of the face, adequately restore ear contour, place scars in a favorable location and ideally accomplish these goals in a single stage with minimal donor site morbidity. METHODS: Eight adult New Zealand rabbits were divided into two groups. 50 ml round tissue expander were implanted to four rabbits. After completion of the expansion, a superiorly based tri-lobed flap was elevated and a new ear was created from the superior dorsal skin of each rabbit. Scintigraphy with Technetium-99m pertecnetate was performed to evaluate flap viability. RESULTS: Subtotal flap necrosis was seen in all animals in non-expanded group. New ear in dimensions of the original ear was created in expanded group without complication. Perfusion and viability of the flaps were proved by Technetium-99m pertecnetate scintigraphy. CONCLUSION: According to our knowledge this study is the first to demonstrate animal model in tri-lobed flap. Also, our technique is the first application of the trilobed flap to the possible ear reconstruction. We speculated that this flap may be used mastoid based without hair, in human. Also, tri-lobed flap may be an alternative in reconstruction of cylindrical organs such as penis or finger