bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Screening Criteria for Salt Tolerance in Wheat under Field and Controlled Environmental Conditions
Authors: El‐Hendawy S. E. , Ruan Y. , Hu Y. , Schmidhalter U. 
Published: June 2009

AbstractAlthough many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. Saline soils are often complex and, therefore, unlikely to show a simple relationship to controlled conditions. To address this deficit, different agronomic and physiological screening criteria for salt tolerance in wheat at different stages were examined under both field and controlled conditions. Four wheat genotypes differing in their salt‐tolerance levels were grown in salt‐affected soil at two different locations and also under greenhouse conditions. Dry weight and leaf area of the upper and lower two leaves of the main stem and total dry weight at Zadoks scale 47 were measured in plants grown under field conditions. The concentrations of Cl−, Na+, K+ and Ca2+ in the upper and lower two leaves of the main stem at Zadoks scale 47 and different yield components were measured in plants grown under both conditions. Our results indicate that measurements derived from the upper two leaves of the main stem were generally more effective as screening criteria than those from the lower two leaves. Correlation coefficients between grain yield and either dry weight or leaf area of the upper two leaves of the main stem indicated that dry weight is inferior to leaf area as a screening criterion under field conditions. Number of sterile spikelets per plant performed well under both conditions, whereas the number of spikelets per plant and 1000‐grain weight failed to distinguish the differences of salt‐tolerance levels among genotypes accurately. Weight and number of grains per plant and number of fertile spikes per plant were poor criteria under controlled conditions, but effective under field conditions. The maintenance of low Cl− and Na+ concentrations in the upper two leaves offered the best guide to salt tolerance under both conditions. Potassium concentration was a poor criterion compared with the selectivity of K+ over Na+, which was useful under both field and controlled conditions. Calcium concentration and Ca2+ over Na+ selectivity in the upper and/or lower two leaves of the main stem were also effective in ranking genotypes according to their salt tolerance under both field and controlled conditions. Therefore, we conclude that simple measurements of the upper two leaves of the main stem including a straightforward measurement of leaf area, visually estimating the number of sterile spikelets, and a quick, practical determination of Na+ and Ca2+ concentration constitute effective criteria to screen wheat genotypes for salt tolerance under both field and controlled conditions.
Evaluation of Common Bean for Drought Tolerance in Juana Diaz, Puerto Rico
Authors: Porch T. G. , Ramirez V. H. , Santana D. , Harmsen E. W. 
Published: June 2009

AbstractDrought tolerance is an increasingly important trait in common bean (Phaseolus vulgaris L.) due to the reduction in water resources, a shift in production areas and increasing input costs. The objective of this study was to evaluate 29 genotypes for drought tolerance under drought stress (DS) and reduced stress treatments in Juana Diaz, Puerto Rico. The use of DS and reduced stress treatments facilitated the identification of drought tolerant germplasm that also had good yield potential under more optimal conditions. Based on the results of seed yield under DS and reduced stress conditions, and DS indices, including the geometric mean (GM), stress tolerance index (STI) and percent yield reduction (YR), genotypes were identified with greater yield potential under the tested environment. Based on average GM over the 2 years, the superior common bean genotypes identified were SEA 5, G 21212, A 686, SEN 21 and SER 21. These genotypes performed well in both years and under both treatment conditions and thus may serve as parents for DS improvement and genetic analysis.
Alleviation of Water Deficit Stress Effects by Foliar Application of Ascorbic Acid on Zea mays L.
Authors: Dolatabadian A. , Modarres Sanavy S. A. M. , Sharifi M. 
Published: June 2009

AbstractThe effects of water‐deficit stress and foliar application of ascorbic acid were studied in leaves of Zea mays L. (single cross 704). The activity of antioxidant enzymes, superoxide dismutase, peroxidase, catalase and polyphenol oxidase was clearly increased by water‐deficit stress. Foliar application of ascorbic acid reduced stress‐induced and antioxidative enzymes activities. Proline and malondialdehyde levels were decreased in water‐deficit stressed plants by ascorbic acid application. It seems that, ascorbic acid application helps the plants for better resistance under the stress by inactivation and scavenging of free radicals. Chlorophyll content was also decreased by water‐deficit stress. The significant decrease of chlorophyll content was obtained in stressed plant than control. Ascorbate was oxidized to dehydroascorbate whereupon total ascorbate was decreased and dehydroascorbate was increased in leaves. The results of the present study indicated that ascorbic acid reduced the harmful effects of reactive oxygen species and improved plant resistance to water stress. In brief, ascorbic acid treatment reduced the damaging action of drought and decreased enzyme activity due to scavenging of reactive oxygen species; thereupon it may be effective for the improvement of stressed plants in arid and semi‐arid regions.
Temporally mediated responses of the diversity of coffee mites to agroforestry management
Authors: Teodoro A. V. , Klein A.‐M. , Tscharntke T. 
Published: June 2009

AbstractManaged agroecosystems have been emphasized for their biodiversity, however, it remains unclear how biodiversity is affected by management practices over time. We assessed the seasonal response of the community of coffee‐inhabiting mites to agroforestry management (simple‐shade agroforests, complex‐shade agroforests and abandoned coffee agroforests) in Ecuador. Species richness of coffee mites was negatively affected by management intensification, with more species in less‐disturbed abandoned agroforests compared to simple‐shade agroforests in the dry (but not in the rainy) season. Overall, the community of coffee‐inhabiting mites varied seasonally, with more species and higher densities in the dry season than in the rainy season. In conclusion, our results show that the coffee mite community responded both to seasonal changes and to management of agroforests, and that vegetationally diverse habitats such as complex‐shade and, in particular, abandoned coffee agroforests contribute to the conservation of mite diversity.
Mating performance of sterile Mexican fruit fly Anastrepha ludens (Dipt., Tephritidae) males used as vectors of Beauveria bassiana (Bals.) Vuill
Authors: Novelo‐Rincón L. F. , Montoya P. , Hernández‐Ortíz V. , Liedo P. , Toledo J. 
Published: June 2009

AbstractField cage tests were carried out to determine the sexual competitiveness, copulation duration and sperm transfer of sterile and wild Mexican fruit fly, Anastrepha ludens (Loew), males that were treated or not treated with Beauveria bassiana (Balsamo) Vuillemin conidia immediately before mating tests. No significant differences in sexual competitiveness were found between untreated sterile males and sterile males treated with conidia, indicating that the presence of conidia did not significantly reduce mating performance. However, both types of sterile males were less competitive than wild untreated males. There were no significant differences in copulation duration and the quantity of sperm transferred between the two groups of sterile males. A positive correlation was found between copulation duration and the quantity of sperm transferred. The four treatments exhibited significant differences regarding the quantity of transferred spermatozoids stored in the spermathecae but there were no differences in the percentages of total sperm stored in each spermatheca. Our results support the idea of using sterile flies as vectors of B. bassiana conidia in controlling fruit fly populations, while, at the same time, reducing the exposure of and harmful effects on non‐target organisms.
Spontaneous electrical and Ca2+signals in the mouse renal pelvis that drive pyeloureteric peristalsis
Authors: Lang Richard J , Hashitani Hikaru , Tonta Mary A , Bourke Justin L , Parkington Helena C , Suzuki Hikaru 
Published: June 2009

Summary1. Peristalsis in the smooth muscle cell (SMC) wall of the pyeloureteric system is unique in physiology in that the primary pacemaker resides in a population of atypical SMCs situated near the border of the renal papilla.2. Atypical SMCs display high‐frequency Ca2+transients upon the spontaneous release of Ca2+from inositol 1,4,5‐trisphosphate (IP3)‐dependent stores that trigger cation‐selective spontaneous transient depolarizations (STDs). In the presence of nifedipine, these Ca2+transients and STDs seldom propagate > 100 μm. Synchronization of STDs in neighbouring atypical SMCs into an electrical signal that can trigger action potential discharge and contraction in the typical SMC layer involves a coupled oscillator mechanism dependent on Ca2+entry through L‐type voltage‐operated Ca2+channels.3. A population of spindle‐ or stellate‐shaped cells, immunopositive for the tyrosine receptor kinase kit, is sparsely distributed throughout the pyeloureteric system. In addition, Ca2+transients and action potentials of long duration occurring at low frequencies have been recorded in a population of fusiform cells, which we have termed interstitial cells of Cajal (ICC)‐like cells.4. The electrical and Ca2+signals in ICC‐like cells are abolished upon blockade of Ca2+release from either IP3‐ or ryanodine‐dependent Ca2+stores. However, the spontaneous Ca2+signals in atypical SMCs or ICC‐like cells are little affected inW/W−vtransgenic mice, which have extensive lesions of their intestinal ICC networks.5. In summary, we have developed a model of pyeloureteric pacemaking in which atypical SMCs are indeed the primary pacemakers, but the function of ICC‐like cells has yet to be determined.
Dielectric breakdown of an unpoled piezoelectric material with a conductive channel
Authors: LIN S. , BEOM H. G. , TAO D. , KIM Y. H. 
Published: June 2009

ABSTRACTThe dielectric breakdown of an unpoled piezoelectric ceramic, PZT807, with a conductive channel, is investigated. Cylindrical bar specimens with a conductive channel are used for breakdown tests of the unpoled piezoelectric ceramic under purely electrical loads. Narrow tubular channels emanating from the head of the initial channel are observed in the specimens after breakdown occurs. The radius of the tubular channel that is created at the surface of the initial channel head is insensitive to various types of channel formation. The problem of a fine tubular channel that emanates from the initial channel head is numerically solved to evaluate the three‐dimensional J integral, which is directly related to the energy that is available at breakdown, at the initiation of a new channel in the specimen. The critical J integral at the onset of breakdown is obtained.
The comparative pressure‐flow plot properties of radiological bladder neck and prostatic obstruction
Authors: Idriz Sanjin , Bishara Samuel , Kirkham Alex , Rickards David , Julian P. , Shah R. , Malone‐Lee James 
Published: June 2009

OBJECTIVESTo test the hypotheses that: (i) significant differences should exist in pressure/flow data between radiologically determined bladder neck and prostatic obstruction; (ii) these differences should inform understanding of the pathophysiology of male outflow obstruction. The biomechanics of the voiding/pressure/flow plot imply that a urodynamic assessment trace should identify outflow obstruction and characterise the urethral viscoelastic properties. Micturating cystourethrograms (MCUG) images might provide a useful diagnostic dichotomy for testing these assumptions.MATERIALS AND METHODSThe pressure/flow data from 71 men who also provided video‐urodynamic imaging data that a radiologist could classify unequivocally as showing bladder neck obstruction (42) or prostatic obstruction (29) were analysed. The following variables were recorded: the detrusor pressure at initiation of voiding (Pdet.open); the detrusor pressure at the end of voiding (Pdet.close); the detrusor pressure at maximum flow rate (Qmax), (Pdet.Qmax), and Qmax. The urethral resistance relation (URR) was drawn onto the pressure‐flow plot and the gradient of the URR, ΔPdet/ΔQ, was calculated.RESULTSThere were significant between group differences in Pdet.open (95% confidence interval of the difference 5.2–28.6, U = 352, P = 0.003); Pdet.close (0.2–15.0, U = 428, P = 0.034); Pdet.Qmax (0.0–18.9, U = 439, P = 0.05); Qmax and ΔPdet/ΔQ did not distinguish between the MCUG groups (95% confidence interval of the difference 2.3–18, U = 111; P = 0.004). The best‐fit model from linear combinations of the data achieved an area under the receiver operator curve of 0.72 for discriminating between the MCUG groups.CONCLUSIONSThe urodynamic assessment identified interesting and coherent biomechanical differences, and could distinguish between the obstructions with a moderate degree of accuracy.
Specular Effects on the GPU: State of the Art
Authors: Szirmay‐Kalos László , Umenhoffer Tamás , Patow Gustavo , Szécsi László , Sbert Mateu 
Published: June 2009

Abstract This survey reviews algorithms that can render specular, i.e. mirror reflections, refractions, and caustics on the GPU. We establish a taxonomy of methods based on the three main different ways of representing the scene and computing ray intersections with the aid of the GPU, including ray tracing in the original geometry, ray tracing in the sampled geometry, and geometry transformation. Having discussed the possibilities of implementing ray tracing, we consider the generation of single reflections/refractions, interobject multiple reflections/refractions, and the general case which also includes self‐reflections or refractions. Moving the focus from the eye to the light sources, caustic effect generation approaches are also examined.
Procedural Arrangement of Furniture for Real‐Time Walkthroughs
Authors: Germer T. , Schwarz M. 
Published: June 2009

Abstract This paper presents a procedural approach to generate furniture arrangements for large virtual indoor scenes. The interiors of buildings in 3D city scenes are often omitted. Our solution creates rich furniture arrangements for all rooms of complex buildings and even for entire cities. The key idea is to only furnish the rooms in the vicinity of the viewer while the user explores a building in real time. In order to compute the object layout we introduce an agent‐based solution and demonstrate the flexibility and effectiveness of the agent approach. Furthermore, we describe advanced features of the system, like procedural furniture geometry, persistent room layouts, and styles for high‐level control.
Evenly Spaced Streamlines for Surfaces: An Image‐Based Approach
Authors: Spencer Benjamin , Laramee Robert S. , Chen Guoning , Zhang Eugene 
Published: June 2009

AbstractWe introduce a novel, automatic streamline seeding algorithm for vector fields defined on surfaces in 3D space. The algorithm generates evenly spaced streamlines fast, simply and efficiently for any general surface‐based vector field. It is general because it handles large, complex, unstructured, adaptive resolution grids with holes and discontinuities, does not require a parametrization, and can generate both sparse and dense representations of the flow. It is efficient because streamlines are only integrated for visible portions of the surface. It is simple because the image‐based approach removes the need to perform streamline tracing on a triangular mesh, a process which is complicated at best. And it is fast because it makes effective, balanced use of both the CPU and the GPU. The key to the algorithm's speed, simplicity and efficiency is its image‐based seeding strategy. We demonstrate our algorithm on complex, real‐world simulation data sets from computational fluid dynamics and compare it with object‐space streamline visualizations.
Volumetric Billboards
Authors: Decaudin Philippe , Neyret Fabrice 
Published: June 2009

Abstract We introduce an image‐based representation, called volumetric billboards, allowing for the real‐time rendering of semi‐transparent and visually complex objects arbitrarily distributed in a 3D scene. Our representation offers full parallax effect from any viewing direction and improved anti‐aliasing of distant objects. It correctly handles transparency between multiple and possibly overlapping objects without requiring any primitive sorting. Furthermore, volumetric billboards can be easily integrated into common rasterization‐based renderers, which allows for their concurrent use with polygonal models and standard rendering techniques such as shadow‐mapping. The representation is based on volumetric images of the objects and on a dedicated real‐time volume rendering algorithm that takes advantage of the GPU geometry shader. Our examples demonstrate the applicability of the method in many cases including levels‐of‐detail representation for multiple intersecting complex objects, volumetric textures, animated objects and construction of high‐resolution objects by assembling instances of low‐resolution volumetric billboards.
Editing Object Behaviour in Video Sequences
Authors: Scholz Volker , El‐Abed Sascha , Seidel Hans‐Peter , Magnor Marcus 
Published: June 2009

AbstractWhile there are various commercial‐strength editing tools available today for still images, object‐based manipulation of real‐world video footage is still a challenging problem. In this system paper, we present a framework for interactive video editing. Our focus is on footage from a single, conventional video camera. By relying on spatio‐temporal editing techniques operating on the video cube, we do not need to recover 3D scene geometry. Our framework is capable of removing and inserting objects, object motion editing, non‐rigid object deformations, keyframe interpolation, as well as emulating camera motion. We demonstrate how movie shots with moderate complexity can be persuasively modified during post‐processing.
Interactive Pixel‐Accurate Free Viewpoint Rendering from Images with Silhouette Aware Sampling
Authors: Hornung A. , Kobbelt L. 
Published: June 2009

AbstractWe present an integrated, fully GPU‐based processing pipeline to interactively render new views of arbitrary scenes from calibrated but otherwise unstructured input views. In a two‐step procedure, our method first generates for each input view a dense proxy of the scene using a new multi‐view stereo formulation. Each scene proxy consists of a structured cloud of feature aware particles which automatically have their image space footprints aligned to depth discontinuities of the scene geometry and hence effectively handle sharp object boundaries and occlusions. We propose a particle optimization routine combined with a special parameterization of the view space that enables an efficient proxy generation as well as robust and intuitive filter operators for noise and outlier removal. Moreover, our generic proxy generation allows us to flexibly handle scene complexities ranging from small objects up to complete outdoor scenes. The second phase of the algorithm combines these particle clouds in real‐time into a view‐dependent proxy for the desired output view and performs a pixel‐accurate accumulation of the colour contributions from each available input view. This makes it possible to reconstruct even fine‐scale view‐dependent illumination effects. We demonstrate how all these processing stages of the pipeline can be implemented entirely on the GPU with memory efficient, scalable data structures for maximum performance. This allows us to generate new output renderings of high visual quality from input images in real‐time.
Adaptive Interleaved Sampling for Interactive High‐Fidelity Rendering
Authors: Dubla P. , Debattista K. , Chalmers A. 
Published: June 2009

AbstractRecent advances have made interactive ray tracing (IRT) possible on consumer desktop machines. These advances have brought about the potential for interactive global illumination (IGI) with enhanced realism through physically based lighting. IGI, unlike IRT, has a much higher computational complexity. Furthermore, since non‐primary rays constitute the majority of the computation, the rays are predominantly incoherent, making impractical many of the methods that have made IRT possible. Two methods that have already shown promise in decreasing the computational time of the GI solution are interleaved sampling and adaptive rendering. Interleaved sampling is a generalized sampling scheme that smoothly blends between regular and irregular sampling while maintaining coherence. Adaptive rendering algorithms adjust rendering quality, non‐uniformally, using a guidance scheme. While adaptive rendering has shown to provide speed‐up when used for off‐line rendering it has not been utilized in IRT due to its naturally incoherent nature. In this paper, we combine adaptive rendering and interleaved sampling within a component‐based solution into a new approach we term adaptive interleaved sampling. This allows us to tailor new adaptive heuristics for interleaved sampling of the individual components of the GI solution significantly improving overall performance. We present a novel component‐based IGI framework for which we achieve interactive frame rates for a range of effects such as indirect diffuse lighting, soft shadows and single scatter homogeneous participating media.
GPU Rendering of Relief Mapped Conical Frusta
Authors: Bhagvat D. , Jeschke S. , Cline D. , Wonka P. 
Published: June 2009

AbstractThis paper proposes to use relief‐mapped conical frusta (cones cut by planes) to skin skeletal objects. Based on this representation, current programmable graphics hardware can perform the rendering with only minimal communication between the CPU and GPU. A consistent definition of conical frusta including texture parametrization and a continuous surface normal is provided. Rendering is performed by analytical ray casting of the relief‐mapped frusta directly on the GPU. We demonstrate both static and animated objects rendered using our technique and compare to polygonal renderings of similar quality.
Interactive Fibre Structure Visualization of the Heart
Authors: Peeters T. H. J. M. , Vilanova A. , Romeny B. M. ter Haar 
Published: June 2009

AbstractThe heart consists of densely packed muscle fibres. The orientation of these fibres can be acquired by using Diffusion Tensor Imaging (DTI) ex vivo. A good way to visualize the fibre structure in a cross section of the heart is by showing short line segments originating from the cross section and aligned with the local direction of the fibres. If the line segments are placed dense enough, one can see how the fibre orientations change. However, generation of the line segments takes time and thus the user has to wait for new geometry to be generated when the plane defining the cross section is changed. We present a new direct rendering method for the visualization of the 3D vector field in a 2D user‐definable cross section of a heart. On the intersection of the plane with the vector field, the full 3D vectors are rendered as 3D line segments with a local ray casting approach. No preprocessing of the data is needed and no geometry is generated. This technique allows a fast inspection of the data to identify interesting areas where further analysis is necessary (e.g. quantification or generation of streamlines). We also show how the technique is generalized to other glyph shapes than line segments by implementing ellipsoids.