bluuebunny/crossref_metadata_2025_split huggingface dataset:
NoRM: No‐Reference Image Quality Metric for Realistic Image Synthesis
Authors: Herzog Robert , Čadík Martin , Aydčin Tunç O. , Kim Kwang In , Myszkowski Karol , Seidel Hans‐P. 
Published: June 2012

AbstractSynthetically generating images and video frames of complex 3D scenes using some photo‐realistic rendering software is often prone to artifacts and requires expert knowledge to tune the parameters. The manual work required for detecting and preventing artifacts can be automated through objective quality evaluation of synthetic images. Most practical objective quality assessment methods of natural images rely on a ground‐truth reference, which is often not available in rendering applications. While general purpose no‐reference image quality assessment is a difficult problem, we show in a subjective study that the performance of a dedicated no‐reference metric as presented in this paper can match the state‐of‐the‐art metrics that do require a reference. This level of predictive power is achieved exploiting information about the underlying synthetic scene (e.g., 3D surfaces, textures) instead of merely considering color, and training our learning framework with typical rendering artifacts. We show that our method successfully detects various non‐trivial types of artifacts such as noise and clamping bias due to insufficient virtual point light sources, and shadow map discretization artifacts. We also briefly discuss an inpainting method for automatic correction of detected artifacts.
Centroidal Voronoi Tessellation of Line Segments and Graphs
Authors: Lu Lin , Lévy Bruno , Wang Wenping 
Published: June 2012

AbstractCentroidal Voronoi Tessellation (CVT) of points has many applications in geometry processing, including re‐meshing and segmentation, to name but a few. In this paper, we generalize the CVT concept to graphs via a variational characterization. Given a graph and a 3D polygonal surface, our method optimizes the placement of the vertices of the graph in such a way that the graph segments best approximate the shape of the surface. We formulate the computation of CVT for graphs as a continuous variational problem, and present a simple, approximate method for solving this problem. Our method is robust in the sense that it is independent of degeneracies in the input mesh, such as skinny triangles, T‐junctions, small gaps or multiple connected components. We present some applications, to skeleton fitting and to shape segmentation.
Medial Kernels
Authors: Berger Matthew , Silva Claudio T. 
Published: June 2012

AbstractWe introduce the medial kernel, an association measure which provides for a robust construction of volume‐aware distances defined directly on point clouds. The medial kernel is a similarity measure defined as the likelihood of two points belonging to a common interior medial ball. We use the medial kernel to construct a random walk on the point cloud, where movement in the walk is restricted to regions containing similar medial balls. Our distances are defined as the diffusion distances of this random walk, assigning low distance to points belonging to similar medial regions. These distances allow for a robust means of processing incomplete point clouds, capable of distinguishing nearby yet separate undersampled components, while also associating points which are far in Euclidean distance yet mutually share an interior volume. We leverage these distances for several applications: volumetric part segmentation, the construction of function bases, and reconstruction‐by‐parts – a surface reconstruction method which adheres to the medial kernel.
A Cell‐Based Light Interaction Model for Human Blood
Authors: Yim D. , Baranoski G.V.G. , Kimmel B.W. , Chen T.F. , Miranda E. 
Published: June 2012

AbstractThe development of predictive appearance models for organic tissues is a challenging task due to the inherent complexity of these materials. In this paper, we closely examine the biophysical processes responsible for the appearance attributes of whole blood, one the most fundamental of these materials. We describe a new appearance model that simulates the mechanisms of light propagation and absorption within the cellular and fluid portions of this specialized tissue. The proposed model employs a comprehensive, and yet flexible first principles approach based on the morphological, optical and biochemical properties of blood cells. This approach allows for environment driven changes in the cells' anatomy and orientation to be appropriately included into the light transport simulations. The correctness and predictive capabilities of the proposed model are quantitatively and qualitatively evaluated through comparisons of modeled results with actual measured data and experimental observations reported in the scientific literature. Its incorporation into rendering systems is illustrated through images of blood samples depicting appearance variations controlled by physiologically meaningful parameters. Besides the contributions to the modeling of material appearance, the research presented in this paper is also expected to have applications in a wide range of biomedical areas, from optical diagnostics to the visualization and noninvasive imaging of blood‐perfused tissues.
Unilateral Climate Policy and Competitiveness: Economic Implications of Differential Emission Pricing
Authors: Böhringer Christoph , Alexeeva‐Talebi Victoria 
Published: June 2012

AbstractUnilateral climate policy raises concerns about international competitiveness and emission leakage that result in preferential regulatory treatment of domestic energy‐intensive and trade‐exposed (EITE) industries. Our applied analysis of unilateral EU abatement illustrates the potential pitfalls of climate policy design which narrowly focuses on competitiveness concerns about EITE industries. The sector‐specific gains of differential emission pricing in favour of these branches must be traded off with the additional burden imposed on other industries. From the perspective of the unilaterally abating region preferential EITE emission pricing can induce non‐negligible excess cost as policy concedes (too) low emission prices to EITE industries and thereby foregoes relatively cheap abatement options in these sectors. With respect to global cost‐effectiveness of unilateral climate policy, we find that differential emission pricing in favour of EITE industries can reduce emission leakage and thereby provide global cost savings compared with uniform pricing. However, the scope for cost savings is limited and may change into substantial cost increases if unilateral reduction targets are moderate and EITE industries get close to exemptions.
Population genetic structure of a threatened tortoise across the south‐eastern United States: implications for conservation management
Authors: Clostio R. W. , Martinez A. M. , LeBlanc K. E. , Anthony N. M. 
Published: June 2012

AbstractThe progressive loss and fragmentation of longleaf pine forests throughout the southeastern United States has led to severe declines in habitat specialists such as the federally listed gopher tortoise Gopherus polyphemus. However, little is known of the range‐wide historical genetic structure of this species or how habitat loss may have impacted the genetic diversity of this species over time. As genetic data are lacking in many parts of the gopher tortoise range, management of federally listed populations in Louisiana and Mississippi have been based on conservation units delineated by rivers. However, this current management strategy has been formulated without any knowledge of how riverine barriers might relate to genetic population structure. Here, we examine variability of mitochondrial and nuclear microsatellite markers in gopher tortoise populations across their natural range in the southeastern United States. Results from the mitochondrial data showed a historical phylogenetic break that is coincident with the Apalachicola River and a novel population assemblage located within western Georgia. Genetic structure based on microsatellite loci revealed high levels of genetic differentiation in some regions and a pattern of isolation by distance at two spatial scales. We also find that rivers across the federally listed portion of the range, do not significantly influence gene flow. Coalescent analyses of population demographic change in gopher tortoises indicate evidence of an ancient and severe population decline at sites across the range. Findings from this study provide important information that will aid in the identification of distinct population units for management and in the formulation of recommendations for the future maintenance of genetic diversity in this species.
Inhibition of NMDA‐type glutamate receptors induces arousal from torpor in hibernating arctic ground squirrels (Urocitellus parryii)
Authors: Jinka Tulasi R. , Rasley Brian T. , Drew Kelly L. 
Published: June 2012

J. Neurochem. (2012) 122, 934–940.AbstractHibernation is an adaptation to overcome periods of resource limitation often associated with extreme climatic conditions. The hibernation season consists of prolonged bouts of torpor that are interrupted by brief interbout arousals. Physiological mechanisms regulating spontaneous arousals are poorly understood, but may be related to a need for gluconeogenesis or elimination of metabolic wastes. Glutamate is derived from glutamine through the glutamate–glutamine cycle and from glucose via the pyruvate carboxylase pathway when nitrogen balance favors formation of glutamine. This study tests the hypothesis that activation of NMDA‐type glutamate receptors (NMDAR) maintains torpor in arctic ground squirrel (arctic ground squirrel (AGS); Urocitellus parryii). Administration of NMDAR antagonists MK‐801 (5 mg/kg, i.p.) that crosses the blood–brain barrier and AP5 (5 mg/kg, i.p.) that does not cross the blood–brain barrier induced arousal in AGS. Central administration of MK‐801 (0.2, 2, 20 or 200 μg; icv) to hibernating AGS failed to induce arousal. Results suggest that activation of NMDAR at a peripheral or circumventricular site is necessary to maintain prolonged torpor and that a decrease in glutamate at these sites may contribute to spontaneous arousal in AGS.
Spatial and spatial‐frequency analysis in visual optics
Authors: Westheimer Gerald 
Published: June 2012

Citation information: Westheimer G. Spatial and spatial‐frequency analysis in visual optics. Ophthalmic Physiol Opt 2012, 32, 271–281. doi: 10.1111/j.1475‐1313.2012.00913.xAbstractBackground:  In the specification of visual targets and their transmission through the eye’s optics to form retinal images, the spatial distribution of energy and its Fourier transform, the spatial‐frequency spectrum, are equivalent, so long as linearity constraints are obeyed. The power spectrum, in which phase has been discarded, is an insufficient descriptor; it does not enable the original object to be reconstituted.Procedure:  Not so well known, and explored here, are joint representations in the space and spatial‐frequency dimensions. Their properties are outlined for some sample targets and for transforms of the Gabor, Difference‐of‐Gaussians and Wigner types. A related approach is one in which other kernel functions, such as the Gaussian or its derivative, are substituted for the cosines in the Fourier transform; here also graphs can be generated which jointly display properties both of the target and of its point‐by‐point representation in a size‐tuned domain.Applications:  This kind of study has application in matching the performance characteristics of optical devices to the eye’s, in optical superresolution, and in the analysis of the demands placed on neural processing in, for example, visual hyperacuity.
Parallactic movement beats binocularity in the presence of external visual noise
Authors: Voges Nicole , Bach Michael , Kommerell Guntram 
Published: June 2012

Citation information: Voges N, Bach M & Kommerell G. Parallactic movement beats binocularity in the presence of external visual noise. Ophthalmic Physiol Opt 2012, 32, 308–316. doi: 10.1111/j.1475‐1313.2012.00917.xAbstractPurpose:  Binocular vision provides a considerable advantage over monocular vision when stationary particles partly obstruct the view. Such situations occur in real life, e.g., when drivers are trying to identify objects through a windshield dotted with snowflakes. In the process of driving, any bumpiness of the road will bring about a parallactic movement of particles on the windshield with respect to the visual object. We investigated whether this parallactic movement diminishes the advantage of binocular over monocular vision.Methods:  Using computer graphics, we simulated a driving situation with snowflakes represented by noise particles on the windshield. Ten observers tried to identify a Landolt ring (8 possible orintations, gap always 2.5 arcmin) presented for 2 s at a viewing distance of 2 m. The partly obstructing noise particles, either stationary or moving vertically at three sinusoidal velocities, were presented at a viewing distance of 0.8 m, corresponding to a stereodisparity well beyond Panum’s fusional area. We compared the percentage of correct responses and the reaction time between binocular and monocular vision.Results:  When the ‘snowflakes’ were stationary, binocular vision yielded more correct responses than monocular vision (52.2 ± 1.8% vs 39.7 ± 1.7%). When the ‘snowflakes’ were moving, the task was much easier and the binocular advantage less pronounced (95.8 ± 1.4% vs 85.3 ± 5.2%). The reaction time with stationary noise was 1.25 s for binocular and 1.31 s for monocular vision. With moving noise, averaged over all three velocities, the reaction time was 1.23 s for binocular and 1.36 s for monocular vision.Conclusion:  Parallactic movement of partly obstructing particles reduces the advantage of binocular over monocular vision to practically irrelevant values.
Effects of error in radius of curvature on the corneal power measurement before and after laser refractive surgery for myopia
Authors: Liu Yongji , Wang Yan , Wang Zhaoqi , Zuo Tong 
Published: June 2012

Citation information: Liu Y, Wang Y, Wang Z & Zuo T. Effects of error in radius of curvature on the corneal power measurement before and after laser refractive surgery for myopia. Ophthalmic Physiol Opt 2012, 32, 355–361. doi: 10.1111/j.1475‐1313.2012.00921.xAbstractPurpose:  To investigate the sources of error in corneal power measurement before and after corneal refractive surgery for myopia.Methods:  The study comprised 28 eyes of six males and eight females with a mean age of 26 (range 18–39 years). The radius of curvature of anterior and posterior corneal surface, Q‐Values of anterior and posterior corneal surface and corneal central thickness were measured by rotating Scheimpflug imaging (Pentacam). The true net power Fg, back vertex power Fv, and keratometric power SimK, were calculated respectively at the apex and at a paracentral area on the 3 mm ring.Results:  For virgin eyes, the overestimation (0.53 ± 0.11 D) of the corneal power by using a keratometric index of 1.3375 was balanced by the underestimation (−0.21 ± 0.09 D) of the corneal power by the error in the radius of curvature, resulting in a relatively small corneal power error with a mean value of 0.33 ± 0.11 D. With the Q‐value changing from −0.09 to −0.41, the percentage balanced by the error in radius of curvature increased from 16% to 73%. However, for eyes after laser refractive surgery, the radius of curvature error lead to an overestimation (0.54 ± 0.16 D) of the corneal power and the keratometric index of 1.3375 again overestimated (1.59 ± 0.26 D) the corneal power, resulting in a large measurement error with a mean value of 2.12 ± 0.40 D. With the Q‐value changing from 0.35 to 1.89, the percentage added by the error in radius of curvature increased from 14% to 32%.Conclusions:  For virgin eyes, the overestimation of the corneal power by using a keratometric index of 1.3375 is balanced by the underestimation of the corneal power by the error in the radius of curvature, resulting in a relatively small corneal power error. However, for eyes after laser refractive surgery, the flatter anterior corneal surface means that the use of a keratometric index of 1.3375 significantly overestimates the corneal power and the radius of curvature error now adds to this overestimation and results in a large measurement error.
Does host adaptation of Tetranychus urticae populations in clementine orchards with a Festuca arundinacea cover contribute to a better natural regulation of this pest mite?
Authors: Aguilar‐Fenollosa Ernestina , Pina Tatiana , Gómez‐Martínez María A. , Hurtado Mónica A. , Jacas Josep A. 
Published: June 2012

AbstractTetranychus urticae Koch (Acari: Tetranychidae) is a key pest of clementine mandarins, Citrus clementina Tanaka (Rutaceae), in Spain. This mite is highly polyphagous and can be easily found in clementine orchards, both in the trees and in the associated flora. In a previous study we found that the use of a cover of Festuca arundinacea Schreber (Poaceae) offered a better regulation of T. urticae populations than either bare soil or the traditional wild cover, which included a mix of weed species. We hypothesized that the selection of two host races of T. urticae, specialized in F. arundinacea and C. clementina, could partly explain the results obtained (bottom‐up regulation). Reciprocal transplant experiments show that sympatric deme × host combinations had higher mean fitness values than the allopatric combinations in clementine, but not in F. arundinacea, for most of the fitness parameters evaluated in our study. Because local adaptation implies mean deme fitness to be systematically higher for the sympatric deme × habitat combinations than for the allopatric ones, these results can be taken as indicative of occurrence of local adaptation in T. urticae. Molecular genetic analyses with microsatellite markers support this conclusion and indicate that local adaptation of T. urticae found in our system may indeed contribute to a better natural regulation of this mite.
Transendocardial cell injection is not superior to intracoronary infusion in a porcine model of ischaemic cardiomyopathy: a study on delivery efficiency
Authors: van der Spoel Tycho I.G. , Vrijsen Krijn R. , Koudstaal Stefan , Sluijter Joost P.G. , Nijsen Johannes Frank W. , de Jong Hugo W. , Hoefer Imo E. , Cramer Maarten‐Jan M. , Doevendans Pieter A. , van Belle Eric , Chamuleau Steven A.J. 
Published: June 2012

AbstractStem cell therapy is a new strategy for chronic ischaemic heart disease in patients. However, no consensus exists on the most optimal delivery strategy. This randomized study was designed to assess cell delivery efficiency of three clinically relevant strategies: intracoronary (IC) and transendocardial (TE) using electromechanical mapping guidance (NOGA) compared to surgical delivery in a chronic pig model of ischaemic cardiomyopathy. Twenty‐four animals underwent delivery of 107 autologous Indium‐oxine‐labelled bone marrow‐derived mesenchymal stem cells (MSC) 4 weeks after infarction and were randomized to one of three groups (n = 8 each group): IC, TE or surgical delivery (reference group). Primary endpoint was defined as percentage (%) of injected dose per organ and assessed by in vivo gamma‐emission counting. In addition, troponin and coronary flow were assessed before and after MSC injection. Blinded endpoint analysis showed no significant difference in efficiency after surgical (16 ± 4%), IC (11 ± 1%) and TE (11 ± 3%) (P = 0.52) injections. IC showed less variability in efficiency compared with TE and surgical injection. Overall, TE injection showed less distribution of MSC to visceral organs compared with other modalities. Troponin rise and IC flow did not differ between the percutaneous groups. This randomized study showed no significant difference in cell delivery efficiency to the myocardium in a clinically relevant ischaemic large animal model between IC and TE delivery. In addition, no differences in safety profile were observed. These results are important in view of the choice of percutaneous cell delivery modality in future clinical stem cell trials.
Predictors of inter‐proximal and midfacial recession following single implant treatment in the anterior maxilla: a multivariate analysis
Authors: Cosyn Jan , Sabzevar Mehran M. , De Bruyn Hugo 
Published: June 2012

AbstractPurposeA number of factors have been associated with soft tissue recession following single implant treatment. However, given the cross‐sectional design of most of these studies and crude associations based on univariate analyses, such factors may only be considered risk indicators. The objective of the present retrospective cohort study using multivariate analyses was to identify predictors of recession.Material and MethodsPatients who had been treated by two periodontists and two prosthodontists in 2006 and 2007 for a single implant in the anterior maxilla were re‐examined in 2009 and their records were scrutinized. Subjects treated via flap surgery with and without ridge re‐contouring were considered. Outcome variables were inter‐proximal and midfacial recession. Explanatory variables included demographic data, the surgical approach and a number of local factors that were evaluated on radiographs taken pre‐operatively or at permanent crown installation (baseline).ResultsData pertaining to 97/115 (60 females, 37 males; mean age 51, SD 13, range 23–80) patients were available for evaluation. Significant bone loss was observed between baseline and re‐examination at the implant surface (0.2–0.3 mm, p < 0.001) and tooth surface (0.3–0.5 mm, p < 0.001). Surgery with ridge re‐contouring demonstrated 0.2 mm additional bone loss at the distal tooth surface when compared to surgery without ridge re‐contouring (p = 0.034). This could be explained by a disparity in possible papilla‐opening procedures (three versus one or two). As a result, regression analyses identified surgery with ridge re‐contouring as a predictor of inter‐proximal recession (OR ≥ 3.4). Pre‐operative bone level at the tooth surface was another predictor of inter‐proximal recession (OR ≥ 2.1). Recession of the distal papilla was also affected by a missing contact point (OR = 221.9), the implant‐to‐tooth distance (OR = 0.3) and the distance of the bone peak to the contact point (OR = 2.9). Midfacial recession was only associated with a buccal shoulder position (OR = 17.2).ConclusionsTo optimize soft tissue levels around single implants, clinicians should limit papilla‐opening procedures and pay utmost attention to a correct implant and contact point positioning.
The Ca2+‐dependent DNases are Involved in Secondary Xylem Development in Eucommia ulmoides
Authors: Chen Hui‐Min , Pang Yu , Zeng Jun , Ding Qi , Yin Shen‐Yi , Liu Chao , Lu Meng‐Zhu , Cui Ke‐Ming , He Xin‐Qiang 
Published: June 2012

AbstractSecondary xylem development has long been recognized as a typical case of programmed cell death (PCD) in plants. During PCD, the degradation of genomic DNA is catalyzed by endonucleases. However, to date, no endonuclease has been shown to participate in secondary xylem development. Two novel Ca2+‐dependent DNase genes, EuCaN1 and EuCaN2, were identified from the differentiating secondary xylem of the tree Eucommia ulmoides Oliv., their functions were studied by DNase activity assay, in situ hybridization, protein immunolocalization and virus‐induced gene silencing experiments. Full‐length cDNAs of EuCaN1 and EuCaN2 contained an open reading frame of 987 bp, encoding two proteins of 328 amino acids with SNase‐like functional domains. The genomic DNA sequence for EuCaN1 had no introns, while EuCaN2 had 8 introns. EuCaN1 and EuCaN2 digested ssDNA and dsDNA with Ca2+‐dependence at neutral pH. Their expression was confined to differentiating secondary xylem cells and the proteins were localized in the nucleus. Their activity dynamics was closely correlated with secondary xylem development. Secondary xylem cell differentiation is influenced by RNAi of endonuclease genes. The results provide evidence that the Ca2+‐dependent DNases are involved in secondary xylem development.