bluuebunny/crossref_metadata_2025 huggingface dataset:
Symbiotic Frankia bacteria in Alnus forests in Mexico and the United States of America: is geographic location a good predictor of assemblage structure?
Authors: Higgins Logan Massie , Kennedy Peter Gault
Published: June 2012

While the biogeography of Alnus species is well characterized, that of their microbial symbionts remains less well understood. Little is known, for example, about how the genotypic richness of Alnus-associated Frankia bacteria varies at the continental scale, and the richness of Alnus-associated Frankia at tropical latitudes has yet to be explored. In this study, we conducted sequence-based analyses of the nifH gene comparing Frankia found in root nodules of two Alnus species in central Mexico with those associated with two Alnus species in the northwestern United States of America (USA). Similar to Frankia assemblages in northwestern USA and other geographic locations, genotypic richness within the Mexican samples was low, with five genotypes total using a ≥97% nifH sequence similarity cutoff. The vast majority of Mexican sequences belonged to genotypes also very common in northwestern USA Alnus forests, although two novel Mexican genotypes were identified. Phylogenetic analyses confirmed that all of the genotypes present in Mexico belong to larger clades of Alnus-associated Frankia. Genotype- and distance-based community analyses indicated that neither geographic location nor the phylogenetic relationships among hosts are strong predictors of Frankia assemblage structure. Our results suggest that factors other than classic biogeography are more influential in determining the continental-scale distribution and diversity of Alnus-associated Frankia.
New alpine plant records for British Columbia and a previously unrecognized biogeographical element in western North America
Authors: Marr Kendrick L. , Hebda Richard J. , MacKenzie William H.
Published: June 2012

The distribution of northern British Columbia alpine plants is poorly documented. To improve our understanding of the flora of this vast, remote region, we collected more than 11 000 specimens from 65 mountains during 2002–2011. Most of these locations had not been visited by botanists. Of the more than 400 species we have collected, two are new to the province, others represent significant range extensions. Twelve species share elements of a disjunct distribution that has apparently not been previously recognized and consists of three regions: (1) northwestern North America; (2) Beartooth Plateau; and (3) northern Colorado. These 12 species appear to be absent from the extensive areas of suitable habitat that occur in the intervening areas. The most reasonable explanation for this pattern is that these species, adapted to arctic–alpine tundra conditions, migrated throughout western North America during the Pleistocene, a time when suitable habitat was much more widespread than now, and subsequently went extinct in many areas as the climate warmed during the Holocene.
Hypholoma lateritiumisolated from coarse woody debris, the forest floor, and mineral soil in a deciduous forest in New Hampshire
Authors: Thompson Therese A. , Thorn R. Greg , Smith Kevin T.
Published: June 2012

Fungi in the Agaricomycetes (Basidiomycota) are the primary decomposers in temperate forests of dead wood on and in the forest soil. Through the use of isolation techniques selective for saprotrophic Agaricomycetes, a variety of wood decay fungi were isolated from a northern hardwood stand in the Bartlett Experimental Forest, New Hampshire, USA. In particular, Hypholoma lateritium (Schaeff.: Fr.) P. Kumm. was isolated from basidiocarps, decaying Acer rubrum L. logs, the Oe organic soil horizon, and the E and BC mineral soil horizons. Identification was confirmed by sequence analysis of the internal transcribed spacer region of nuclear ribosomal DNA. All isolates had identical sequences in this region to previously published sequences for the species; some were monokaryotic and simple-septate and others were dikaryotic, with clamp connections. Isolates were further characterized by banding patterns (DNA fingerprints) produced with PCR primers based in simple repetitive sequences and the minisatellite M13. Nine dikaryotic isolates from basidiocarps and from soil horizons Oe, E, and BC had identical fingerprint patterns with all primers tested. The confirmed presence of H. lateritium suggests that this fungus could form a mycelial translocation network that bridges mineral and organic soil horizons and decaying logs.
Systematics of disjunct northeastern Asian and northern North AmericanAllium(Amaryllidaceae)
Authors: Choi Hyeok Jae , Giussani Liliana M. , Jang Chang Gee , Oh Byoung Un , Cota-Sánchez J. Hugo
Published: June 2012

This study was undertaken to better understand Allium infrageneric taxonomy, character evolution, species diversification, and patterns of radiation in disjunct species between the New and Old World using morphological and molecular data. Taxonomic sampling focused on northeastern Asian (mainly Korean and northeastern Chinese) and representative disjunct northern North American (Canadian) species. Pistil and seed testa morphology was investigated using light and scanning electron microscopy, respectively. These characters were useful to assess degree of relationship at different taxonomic levels in Allium. Phylogenetic studies included nrDNA ITS and cpDNA trnL–trnF sequence data analyzed using maximum parsimony approaches. Our molecular phylogeny recovers a similar topology to that published in recent studies and confirms three major evolutionary lines and patterns of radiation regarding the ancestors of subgenera Amerallium and Anguinum in the genus. The northeastern Asian and northern North American disjunction in this genus is inferred to be the result of multiple intercontinental migrations. Seed testa sculpture attributes in combination with seed shape provide key characters to distinguish Allium’s major clades in the molecular phylogeny. The two types of ovarian processes, basal hood-like and apical crest-like in disjunct Old and New World species, respectively, are newly derived characters in each continent. Most infrageneric Allium groups are monophyletic, while subgenus Cepa is polyphyletic.
Boreal forests of eastern Canada revisited: old growth, nonfire disturbances, forest succession, and biodiversity
Authors: Bergeron Yves , Fenton Nicole J.
Published: June 2012

Boreal forests have commonly been described as dominated by monospecific postfire stands that are reburnt well before other ecological process than those occurring immediately after fire can take place. Research undertaken over the last 30 years has given us a very different perspective of the complexity of Canadian boreal forests. Old-growth forests are common and their development is controlled by nonfire disturbances. Consequently, monospecific even-aged stands can develop towards more diversified uneven-aged stands with increasing time since fire. This complex disturbance regime, including both fire and nonfire disturbances, is partially responsible for a higher than expected biodiversity (e.g., understory) in these forests. The dominating forest management model in Canadian boreal forests, based on clear-cut harvesting and regeneration of short rotation even-aged stands, does not reflect the complexities of the disturbance–succession cycle observed in Canadian natural boreal forests.
Discussion of “Geochemical signature of Ordovician Mn-rich sedimentary rocks on the Avalonian shelf”1Appears in Canadian Journal of Earth Sciences, 2011, 48(4): 703–718 [doi: 10.1139/e10-092].
Authors: Waldron John W.F. , White Chris E.
Published: June 2012

The paper “Geochemical signature of Ordovician Mn-rich sedimentary rocks on the Avalonian shelf” (Romer et al., published in 2011) describes six samples of which four are from the Meguma Supergroup of Nova Scotia. Previous work indicates that these samples are Cambrian and that they were deposited in a deep-water turbidite basin (“Megumia”), not on the Avalonian shelf. The geochemical data support models for Mn concentration, involving oxidation and reduction in a sedimentary environment but do not constrain water depth. Likely correlatives are in the Cambrian of North Wales and not in the European localities sampled by the authors.
Environmental and seasonal controls on riverine dissolved uranium in the Hudson, James, and Ungava bays region, Canada
Authors: Rosa Eric , Hillaire-Marcel Claude , Ghaleb Bassam , Dick Terry A.
Published: June 2012

This study documents the spatiotemporal variability of riverine uranium contents and fluxes in rivers discharging into the Hudson, James, and Ungava bays (HJUB). Samples retrieved during a monitoring program of the Koksoak, Great Whale, La Grande, and Nelson rivers were analyzed for dissolved uranium concentration [U] and activity ratio (234U/238U). Field surveys conducted during baseflow and snowmelt in six other rivers of the HJUB basin provided complementary data. It is estimated that altogether, the studied rivers export 3.4 × 105 mol/year of U towards the HJUB, with a discharge weighted average (234U/238U) of 1.27. Two main factors appear to control seasonal fluctuations in dissolved U exports from HJUB rivers: snowmelt and anthropogenic flow control. Under natural hydrological regimes, the dilution of U caused by snowmelt does not compensate for the associated increase in discharge, and riverine U fluxes are intensified during springtime. Contrastingly, the timing of riverine U exports is decoupled from hydroclimatic conditions in rivers affected by flow-control structures. Despite the seasonal variations in riverine U contents, the sampling profiles carried along two of the monitored rivers reveal that within the study region, sample locality is at least as important as sampling time for evaluating riverine U fluxes. In addition, a compilation of data from North American rivers reveals that spatial variations in riverine U contents seem to respond to a prominent lithological control, as rivers draining sedimentary rocks (with abundant carbonates) tend to present overall higher U contents and lower (234U/238U) variability than the rivers of the Canadian Shield.
OBSERVATION OF A RIDGE CORRELATION STRUCTURE IN HIGH MULTIPLICITY PROTON–PROTON COLLISIONS: A BRIEF REVIEW
Authors: LI WEI
Published: June 2012

This paper briefly reviews the striking experimental observation of a ridge-like dihadron correlation structure in high multiplicity proton–proton collisions at the Large Hadron Collider (LHC). Recent progress of both experimental and theoretical efforts on understanding the physical origin of the novel effect is reviewed. Outlook on future direction of possible new studies is discussed.
PERMITTIVITY IN PERTURBED MOLECULAR NANOFILMS
Authors: MARKOSKI BRANKO , ŠETRAJČIĆ JOVAN P. , PETREVSKA MIROSLAVA , VUČENOVIĆ SINIŠA
Published: June 2012

A microscopic theory of dielectric properties of thin molecular films, i.e., quasi 2D systems bounded by two surfaces parallel to XY planes was formulated. Harmonic exciton states were calculated using the method of two-time, retarded, temperature dependent Green's functions. It has been shown that two types of excitations can occur: bulk and surface exciton states. Analysis of the optical properties of these crystalline systems for low exciton concentration shows that the permittivity strongly depends on boundary parameters and the thickness of the film. Conditions for the appearance of localized or unoccupied exciton states have been especially analyzed.
INHERENT PROPERTIES OF TERNARY $(A^{N}B^{2+N}C_{2}^{7-N})$ TETRAHEDRAL SEMICONDUCTORS
Authors: VERMA A. S. , SHARMA SHEETAL , JINDAL V. K.
Published: June 2012

In this paper we have evaluated inherent properties (i.e., heat of formation and cohesive energy) for chalcopyrite structured solids. We have presented two expressions relating the heat of formation and cohesive energy for [Formula: see text] and [Formula: see text] semiconductors with the product of ionic charge (ZAZBZC) and nearest neighbor distance (d in Å). The heat of formation and cohesive energy of these solids exhibit a linear relationship when plotted on a log–log scale against the nearest neighbor distance, but fall on different straight lines according to the product of ionic charge of the compounds. We have applied the modified relations on these solids and found a better agreement with experimental data as compared to the values evaluated by previous researchers so far. The results for heat of formation differ from experimental values by the following amounts: ZnSiP 2 — 4.8%, ZnSnP 2 — 0.4%, ZnSiAs 2 — 0.7%, ZnGeAs 2 — 2.6%, ZnSnAs 2 — 1.2%, CdGeP 2 — 3.8%, CuGaSe 2 — 0.3% and AgInSe 2 — 5% and the results for cohesive energy differ from experimental values by the following amounts: ZnSiP 2 — 0.3%, ZnSnAs 2 — 1.5%, CuGaSe 2 — 3.7%, CuGaTe 2 — 2%, CuInTe 2 — 2.7%, AgGaTe 2 — 0.7%, AgInSe 2 — 3%, AgInTe 2 — 3%.
ELECTRONIC AND ELASTIC PROPERTIES OF CrO2 IN THE ORTHORHOMBIC CaCl2-TYPE STRUCTURE
Authors: WU H. Y. , CHEN Y. H. , DENG C. R. , SU X. F.
Published: June 2012

The structure, electronic and elastic properties of CrO 2 in the high pressure orthorhombic CaCl 2 (Pnnm) phase are investigated by first-principles calculations based on density functional theory (DFT). Our calculated crystal parameters are in good agreement with the available experimental data. The electronic band structure, density of state (DOS) and projected density of state (PDOS) at 14 GPa are studied within local spin density approximation (LSDA) and generalized gradient approximation (GGA) in details. The CaCl 2 phase of CrO 2 still has the half metal character, which is in accordance with previous theoretical predictions. The elastic constants, bulk modulus, shear modulus, Young's modulus and Poisson ratio under pressures are successfully obtained for the orthorhombic CaCl 2 phase of CrO 2. This structure is mechanically stable at our applied range of pressures. The calculated elastic anisotropic factors show that the CaCl 2 phase of CrO 2 is provided with high elastic anisotropy and the elastic anisotropy decreases with increasing pressures. The propagation speed of transverse, longitudinal elastic wave together with associated Debye temperatures are also estimated.
NONUNIVERSAL TUNNELING RESISTANCE AT THE QUANTUM CRITICAL POINT OF MESOSCOPIC SQUIDS ARRAY
Authors: SARKAR SUJIT
Published: June 2012

We calculate the tunneling resistance at the quantum critical point of a mesoscopic SQUIDs array in the presence of magnetic flux. We observe nonuniversal bahaviour of tunneling resistance. We find the analytical relation between the magnetic flux induced dissipation strength and the Luttinger liquid parameter of the system. We also predict the evidence of length scale independent metallic state. This study also emphasizes the importance of co-tunneling effect.
SHELL CORRECTIONS FOR HEAVY AND SUPERHEAVY NUCLEI
Authors: ISMAIL M. , ADEL A.
Published: June 2012

The shell and pairing correction energies are calculated for heavy and superheavy nuclei (SHN) by means of the Strutinsky's method. The single-particle (s.p.) energy levels are obtained from the diagonalization of the Woods–Saxon s.p. Hamiltonian in the deformed harmonic oscillator basis for both neutrons and protons. The residual pairing interaction is calculated by means of the usual Bardeen–Cooper–Schrieffer (BCS) approximation. A two-dimensional deformation space describing axially and reflection-symmetric shapes of nuclei has been used. Based on the shell and pairing correction energies, the signatures of the magic numbers appear at the spherical shell closures Z = 82, 114, 164 and N = 126, 184, 228 and 308. There are also signatures for some other shell closures at, e.g., Z = 108 and N = 162 which appear only when the deformation degrees of freedom is taken into account.
A MODEL FOR THE SIMULATION OF CROSSWIND INTEGRATED CONCENTRATIONS IN THE SURFACE-BASED INVERSION LAYER
Authors: MODANI MANISH , SHARAN MAITHILI
Published: June 2012

A dispersion model for the estimation of crosswind integrated concentrations in the surface-based inversion is proposed. The generalized forms of eddy diffusivity with spatial dependence in both horizontal and vertical directions and vertical height-dependent wind speed are considered. In view of the computational limitation associated with numerical models for Dirac-delta function, the source term is expressed as a limiting case of normal distribution. The accuracy of the employed numerical scheme to solve the resulting partial differential equation with appropriate physically relevant boundary conditions is checked with those obtained from the respective analytical solutions available in literature for the particular forms of eddy diffusivity and wind speed. Concentrations computed from the proposed model are found close to those obtained from analytical models. The concentrations obtained from the proposed model are evaluated for the generalized functional forms of eddy diffusivity (Degrazia and Moraes, 1992; Degrazia et al., 2001) and diabatic logarithmic profile as well as power-law profile of wind speed with the observations from Hanford (Doran et al., 1984) and Copenhagen (Gryning and Lyck, 1984) diffusion experiments in stable and unstable conditions, respectively. Majority of the cases i.e., 64% and 96% are predicted in factor of two to observations in both stable and unstable conditions, respectively.
Printing reflectance functions
Authors: Malzbender Tom , Samadani Ramin , Scher Steven , Crume Adam , Dunn Douglas , Davis James
Published: June 2012

The reflectance function of a scene point captures the appearance of that point as a function of lighting direction. We present an approach to printing the reflectance functions of an object or scene so that its appearance is modified correctly as a function of the lighting conditions when viewing the print. For example, such a “photograph” of a statue printed with our approach appears to cast shadows to the right when the “photograph” is illuminated from the left. Viewing the same print with lighting from the right will cause the statue's shadows to be cast to the left. Beyond shadows, all effects due to the lighting variation, such as Lambertian shading, specularity, and inter-reflection can be reproduced. We achieve this ability by geometrically and photometrically controlling specular highlights on the surface of the print. For a particular viewpoint, arbitrary reflectance functions can be built up at each pixel by controlling only the specular highlights and avoiding significant diffuse reflections. Our initial binary prototype uses halftoning to approximate continuous grayscale reflectance functions.
Variational mesh decomposition
Authors: Zhang Juyong , Zheng Jianmin , Wu Chunlin , Cai Jianfei
Published: June 2012

The problem of decomposing a 3D mesh into meaningful segments (or parts) is of great practical importance in computer graphics. This article presents a variational mesh decomposition algorithm that can efficiently partition a mesh into a prescribed number of segments. The algorithm extends the Mumford-Shah model to 3D meshes that contains a data term measuring the variation within a segment using eigenvectors of a dual Laplacian matrix whose weights are related to the dihedral angle between adjacent triangles and a regularization term measuring the length of the boundary between segments. Such a formulation simultaneously handles segmentation and boundary smoothing, which are usually two separate processes in most previous work. The efficiency is achieved by solving the Mumford-Shah model through a saddle-point problem that is solved by a fast primal-dual method. A preprocess step is also proposed to determine the number of segments that the mesh should be decomposed into. By incorporating this preprocessing step, the proposed algorithm can automatically segment a mesh into meaningful parts. Furthermore, user interaction is allowed by incorporating the user's inputs into the variational model to reflect the user's special intention. Experimental results show that the proposed algorithm outperforms competitive segmentation methods when evaluated on the Princeton Segmentation Benchmark.
Symmetry-guided texture synthesis and manipulation
Authors: Kim Vladimir G. , Lipman Yaron , Funkhouser Thomas
Published: June 2012

This article presents a framework for symmetry-guided texture synthesis and processing. It is motivated by the long-standing problem of how to optimize, transfer, and control the spatial patterns in textures. The key idea is that symmetry representations that measure autocorrelations with respect to all transformations of a group are a natural way to describe spatial patterns in many real-world textures. To leverage this idea, we provide methods to transfer symmetry representations from one texture to another, process the symmetries of a texture, and optimize textures with respect to properties of their symmetry representations. These methods are automatic and robust, as they don't require explicit detection of discrete symmetries. Applications are investigated for optimizing, processing, and transferring symmetries and textures.
Topology-adaptive interface tracking using the deformable simplicial complex
Authors: Misztal Marek Krzysztof , Bærentzen Jakob Andreas
Published: June 2012

We present a novel, topology-adaptive method for deformable interface tracking, called the
Deformable Simplicial Complex
(DSC). In the DSC method, the interface is represented explicitly as a piecewise linear curve (in 2D) or surface (in 3D) which is a part of a discretization (triangulation/tetrahedralization) of the space, such that the interface can be retrieved as a set of faces separating triangles/tetrahedra marked as
inside
from the ones marked as
outside
(so it is also given implicitly). This representation allows robust topological adaptivity and, thanks to the explicit representation of the interface, it suffers only slightly from numerical diffusion. Furthermore, the use of an unstructured grid yields robust adaptive resolution. Also, topology control is simple in this setting. We present the strengths of the method in several examples: simple geometric flows, fluid simulation, point cloud reconstruction, and cut locus construction.
The COMPASS Family of Histone H3K4 Methylases: Mechanisms of Regulation in Development and Disease Pathogenesis
Authors: Shilatifard Ali
Published: June 2012

The Saccharomyces cerevisiae Set1/COMPASS was the first histone H3 lysine 4 (H3K4) methylase identified over 10 years ago. Since then, it has been demonstrated that Set1/COMPASS and its enzymatic product, H3K4 methylation, is highly conserved across the evolutionary tree. Although there is only one COMPASS in yeast, Drosophila possesses three and humans bear six COMPASS family members, each capable of methylating H3K4 with nonredundant functions. In yeast, the histone H2B monoubiquitinase Rad6/Bre1 is required for proper H3K4 and H3K79 trimethylations. The machineries involved in this process are also highly conserved from yeast to human. In this review, the process of histone H2B monoubiquitination-dependent and -independent histone H3K4 methylation as a mark of active transcription, enhancer signatures, and developmentally poised genes is discussed. The misregulation of histone H2B monoubiquitination and H3K4 methylation result in the pathogenesis of human diseases, including cancer. Recent findings in this regard are also examined.
A Mitochondrial Odyssey
Authors: Neupert Walter
Published: June 2012

Good fortune let me be an innocent child during World War II, a hopeful adolescent with encouraging parents during the years of German recovery, and a self-determined adult in a period of peace, freedom, and wealth. My luck continued as a scientist who could entirely follow his fancy. My mind was always set on understanding how things are made. At a certain point, I found myself confronted with the question of how mitochondria and organelles, which cannot be formed de novo, are put together. Intracellular transport of proteins, their translocation across the mitochondrial membranes, and their folding and assembly were the processes that fascinated me. Now, after some 30 years, we have wonderful insights, unimagined views of a complex and at the same time simple machinery and its workings. We have glimpses of how orderly processes are established in the cell to assemble from single molecules our beautiful mitochondria that every day make some 50 kg of ATP for each of us. At the same time, we have learned amazing lessons from the tinkering of evolution that developed mitochondria from bacteria.
The disposition index: from individual to population approach
Authors: Denti Paolo , Toffolo Gianna Maria , Cobelli Claudio
Published: June 2012

To correctly evaluate the glucose control system, it is crucial to account for both insulin sensitivity and secretion. The disposition index (DI) is the most widely accepted method to do so. The original paradigm (hyperbolic law) consists of the multiplicative product of indices related to insulin sensitivity and secretion, but more recently, an alternative formula has been proposed with the exponent α (power function law). Traditionally, curve-fitting approaches have been used to evaluate the DI in a population: the algorithmic implementations often introduce some critical issues, such as the assumption that one of the two indices is error free or the effects of the log transformation on the measurement errors. In this work, we review the commonly used approaches and show that they provide biased estimates. Then we propose a novel nonlinear total least square (NLTLS) approach, which does not need to use the approximations built in the previously proposed alternatives, and show its superiority. All of the traditional fit procedures, including NLTLS, account only for uncertainty affecting insulin sensitivity and secretion indices when they are estimated from noisy data. Thus, they fail when part of the observed variability is due to inherent differences in DI values between individuals. To handle this inevitable source of variability, we propose a nonlinear mixed-effects approach that describes the DI using population hyperparameters such as the population typical values and covariance matrix. On simulated data, this novel technique is much more reliable than the curve-fitting approaches, and it proves robust even when no or small population variability is present in the DI values. Applying this new approach to the analysis of real IVGTT data suggests a value of α significantly smaller than 1, supporting the importance of testing the power function law as an alternative to the simpler hyperbolic law.
Superparamagnetic Nanoparticles and RNAi‐Mediated Gene Silencing: Evolving Class of Cancer Diagnostics and Therapeutics
Authors: Dey Sanchareeka , Maiti Tapas K.
Published: June 2012

The ever increasing death of patients affected by various types of fatal cancers is of concern worldwide. Curative attempts by radiation/chemotherapy and surgery are often a failure in the long run. Moreover, adverse side effects of such treatments burden the patients with painful survival at the last phase of their life. The failure of early diagnosis is one of the root causes of the problem. Intensive research activities are being pursued in reputed laboratories across the globe to find superior diagnostics and therapeutics. Over the last decade, a number of publications have highlighted RNA interference based silencing of cancer‐related gene expression as a promising technology to tackle the aforesaid problems. Superparamagnetic iron oxide nanoparticles (SPIONs) are reported to be excellent vehicles for short‐interfering RNA (siRNA). The SPION‐siRNA conjugate is biocompatible, stable, and amenable to specific targeting and can cross the blood brain barrier. The issues related to their synthesis, surface properties, delivery, tracking, imaging in relevance to cancer diagnostic and therapeutic, and so forth demand an extensive review, and we have addressed these aspects in this paper. The future prospects of the technology have also been traced.
Concurrent Stenoocclusive Disease of Intracranial and Extracranial Arteries in a Patient with Polycythemia Vera
Authors: Hua Le H. , Dodd Robert L. , Schwartz Neil E.
Published: June 2012

Moyamoya disease is a stenoocclusive disease involving the intracranial carotid and proximal middle cerebral arteries. There are rarely any additional extracranial stenoses occurring concurrently with moyamoya. The pathophysiology of moyamoya remains obscure, but hematologic disorders, notably sickle-cell anemia, have been associated in some cases. We describe the novel case of polycythemia vera associated with severe steno-occlusive disease of both intracranial and extracranial large arteries. A 47-year-old woman with polycythemia vera had multiple transient ischemic attacks, and noninvasive vessel imaging revealed steno-occlusive disease of bilateral supraclinoid internal carotid arteries with moyamoya-type collaterals, proximal left subclavian artery, right vertebral artery origin, bilateral renal arteries, superior mesenteric artery, and right common iliac artery. Laboratory workup for systemic vasculitis was negative. She required bilateral direct external carotid to internal carotid bypass procedures and percutaneous balloon angioplasty of her right VA origin stenosis. This case suggests that hematologic disorders can lead to vessel stenoses and occlusion. The pathophysiology may be due to a prothrombotic state leading to repeated endothelial injury, resultant intimal hyperplasia, and progressive steno-occlusion.
A New Iterative Scheme for Solving the Equilibrium Problems, Variational Inequality Problems, and Fixed Point Problems in Hilbert Spaces
Authors: Wangkeeree Rabian , Preechasilp Pakkapon
Published: June 2012

We introduce the new iterative methods for finding a common solution set of monotone,
Lipschitz‐type continuous equilibrium problems and the set of fixed point of nonexpansive mappings which is a unique
solution of some variational inequality. We prove the strong convergence theorems of such iterative scheme in a real
Hilbert space. The main result extends various results existing in the current literature.
Development of Embedded CAPTCHA Elements for Bot Prevention in Fischer Random Chess
Authors: McDaniel Ryan , Yampolskiy Roman V.
Published: June 2012

Cheating in chess can take many forms and has existed almost as long as the game itself. The advent of computers has introduced a new form of cheating into the game. Thanks to the computational power of modern-day computers, a player can use a program to calculate thousands of moves for him or her, and determine the best possible scenario for each move and countermove. These programs are often referred to as “bots,” and can even play the game without any user interaction. In this paper, we describe a methodology aimed at preventing bots from participating in online chess games. The proposed approach is based on the integration of a CAPTCHA protocol into a game scenario, and the subsequent inability of bots to accurately track the game states. This is achieved by rotating the images of the individual chess pieces and adjusting their resolution in an attempt to render them unreadable by a bot. Feedback from users during testing shows that there is minimal impact on their ability to play the game. Players rated the difficulty of reading the pieces on a scale of one to ten, with an average rank of 6.5. However, the average number of moves to adjust to the distorted pieces was only 3.75. This tells us that, although it is difficult to read the pieces at first, it is easy to adjust quickly to the new image.
Genetic Insights into Bicuspid Aortic Valve Formation
Authors: Laforest Brigitte , Nemer Mona
Published: June 2012

Bicuspid aortic valve (BAV) is the most common congenital heart defect, affecting 1-2% of the population. It is generally diagnosed late in adulthood when deterioration of the abnormal leaflet becomes clinically evident. BAV patients have an increased risk of developing serious complications, including stenosis, regurgitation, endocarditis, dilation of the aorta, aortic dissection, and aneurysm. BAV is a heritable trait, but the genetic basis underlying this cardiac malformation remains poorly understood. In the last decade, thanks to studies in animal models as well as genetic and biochemical approaches, a large number of genes that play important roles in heart development have been identified. These discoveries provided valuable insight into cardiac morphogenesis and uncovered congenital-heart-disease-causing genes. This paper will summarize the current knowledge of valve morphogenesis as well as our current understanding of the genetic pathways involved in BAV formation. The impact of these advances on human health including diagnosis of BAV and prevention of cardiovascular complications in individuals with BAV or with a family history of BAV is also discussed.
Impact of Poultry Litter Cake, Cleanout, and Bedding following Chemical Amendments on Soil C and N Mineralization
Authors: Watts Dexter B. , Smith Katy E. , Torbert H. A.
Published: June 2012

Poultry litter is a great alternative N source for crop production. However, recent poultry litter management changes, and increased chemical amendment use may impact its N availability. Thus, research was initiated to evaluate the effect that broiler cake and total cleanout litter amended with chemical additives have on C and N mineralization. A 35-day incubation study was carried out on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults) soil common to the USA Appalachian Plateau region. Three poultry litter components (broiler cake, total cleanout, and bedding material) from a broiler house were evaluated and compared to a soil control. Chemical amendments lime (CaCO3), gypsum (CaSO4), aluminum sulfate (AlSO4), and ferrous sulfate (FeSO4) were added to the poultry litter components to determine their impact on C and N mineralization. Litter component additions increased soil C mineralization in the order of broiler cake > total cleanout > bedding > soil control. Although a greater concentration of organic C was observed in the bedding, broiler cake mineralized the most C, which can be attributed to differences in the C : N ratio between treatments. Chemical amendment in addition to the manured soil also impacted C mineralization, with AlSO4generally decreasing mineralization. Nitrogen mineralization was also significantly affected by poultry litter component applications. Broiler cake addition increased N availability followed by total cleanout compared to soil control, while the bedding resulted in net N immobilization. Chemical amendments impacted N mineralization primarily in the broiler cake amended soil where all chemical amendments decreased mineralization compared to the no chemical amendment treatment. This short-term study (35-day incubation) indicates that N availability to crops may be different depending on the poultry litter component used for fertilization and chemical amendment use which could decrease N mineralization.
Outcomes of and Satisfaction with the Inflatable Penile Prosthesis in the Elderly Male
Authors: Villarreal Humberto G. , Jones LeRoy
Published: June 2012

Objective. To determine the outcomes of and satisfaction with the multi-component inflatable penile prosthesis (IPP) in the elderly male (age >71).Methods. Using a chart review and telephone survey, we retrospectively assessed patients who underwent IPP or combined IPP/artificial urinary sphincter (AUS) from 2004–2006.Results. We identified 56 patients that underwent IPP (48) or IPP/AUS (8). The age range was 71–86 (mean 74.3) at the time of surgery, with a follow-up range of 0.5–2.4 years (mean 1.5). The overall complication rate was 3.8% (2 of 56) with one device removed for infection and a second patient requiring exploration for a postoperative hematoma. The telephone interview was conducted with 35 of 56 patients. Patients rated ease of use (a scale from 1–5, 5 meaning very easy) and overall satisfaction (a scale of 1–5, 5 meaning very satisfied) at an average of 4.1 and 4.3, respectively. IPP usage varied from 0–7 times per month (mean 3.3). 32 of 35 patients (91%) said they would undergo the procedure again.Conclusion. Our review demonstrates that the IPP is well tolerated in the elderly male population, who report a high degree of satisfaction and ease of use with this device.
Enhanced Multistage Differential Transform Method: Application to the Population Models
Authors: Do Younghae , Jang Bongsoo
Published: June 2012

We present an efficient computational algorithm, namely, the enhanced multistage differential transform method (E‐MsDTM) for solving prey‐predator systems. Since the differential transform method (DTM) is based on the Taylor series, it is difficult to obtain accurate approximate solutions in large domain. To overcome this difficulty, the multistage differential transform method (MsDTM) has been introduced and succeeded to have reliable approximate solutions for many problems. In MsDTM, it is the key to update an initial condition in each subdomain. The standard MsDTM utilizes the approximate solution directly to assign the new initial value. Because of local convergence of the Taylor series, the error is accumulated in a large domain. In E‐MsDTM, we propose the new technique to update an initial condition by using integral operator. To demonstrate efficiency of the proposed method, several numerical tests are performed and compared with ones obtained by other numerical methods such as MsDTM, multistage variational iteration method (MVIM), and fourth‐order Runge‐Kutta method (RK4).
Treatment with Y-27632, a ROCK Inhibitor, Increases the Proinvasive Nature of SW620 Cells on 3D Collagen Type 1 Matrix
Authors: Vishnubhotla Ramana , Bharadwaj Shruthi , Sun Shan , Metlushko Vitali , Glover Sarah C.
Published: June 2012

The concept of using tissue density as a mechanism to diagnose a tumor has been around for centuries. However, this concept has not been sufficiently explored in a laboratory setting. Therefore, in this paper, we observed the effects of cell density and extracellular matrix (ECM) density on colon cancer invasion and proliferation using SW620 cells. We also attempted to inhibit ROCK-I to determine its effect on cell invasion and proliferation using standard molecular biology techniques and advanced imaging. Increasing cell seeding density resulted in a 2-fold increase in cell invasion as well as cell proliferation independent of treatment with Y-27632. Increasing collagen I scaffold density resulted in a 2.5-fold increase in cell proliferation while treatment with Y-27632 attenuated this effect although 1.5 fold increase in cell invasion was observed in ROCK inhibited samples. Intriguingly, ROCK inhibition also resulted in a 3.5-fold increase in cell invasion within 3D collagen scaffolds for cells seeded at lower densities. We show in this paper that ROCK-I inhibition leads to increased invasion within 3D collagen I microenvironments. This data suggests that although ROCK inhibitors have been used clinically to treat several medical conditions, its effect largely depends on the surrounding microenvironment.
Positive Solutions for Some Nonlinear Elliptic Systems in Exterior Domains of ℝ2
Authors: Alsaedi Ramzi
Published: June 2012

Using some potential theory tools and the Schauder fixed point theorem, we prove the existence of positive continuous solutions with a precise global behavior for the competitive semilinear elliptic system Δu = p(x)uαvr, Δv = q(x)usvβ in an exterior domain D of ℝ2, subject to some Dirichlet conditions, where α ≥ 1, β ≥ 1, r ≥ 0, s ≥ 0 and the potentials p, q are nonnegative and satisfy some hypotheses related to the Kato class K(D).
Noise-Assisted Instantaneous Coherence Analysis of Brain Connectivity
Authors: Hu Meng , Liang Hualou
Published: June 2012

Characterizing brain connectivity between neural signals is key to understanding brain function. Current measures such as coherence heavily rely on Fourier or wavelet transform, which inevitably assume the signal stationarity and place severe limits on its time-frequency resolution. Here we addressed these issues by introducing a noise-assisted instantaneous coherence (NAIC) measure based on multivariate mode empirical decomposition (MEMD) coupled with Hilbert transform to achieve high-resolution time frequency representation of neural coherence. In our method, fully data-driven MEMD, together with Hilbert transform, is first employed to provide time-frequency power spectra for neural data. Such power spectra are typically sparse and of high resolution, that is, there usually exist many zero values, which result in numerical problems for directly computing coherence. Hence, we propose to add random noise onto the spectra, making coherence calculation feasible. Furthermore, a statistical randomization procedure is designed to cancel out the effect of the added noise. Computer simulations are first performed to verify the effectiveness of NAIC. Local field potentials collected from visual cortex of macaque monkey while performing a generalized flash suppression task are then used to demonstrate the usefulness of our NAIC method to provide highresolution time-frequency coherence measure for connectivity analysis of neural data.
Photocatalytic Degradation of Methylene Blue by Fe/ZnO/SiO2Nanoparticles under Visiblelight
Authors: Mohamed R. M. , Mkhalid I. A. , Baeissa E. S. , Al-Rayyani M. A.
Published: June 2012

The photocatalytic activity of Fe/ZnO/SiO2catalysts under visible-light irradiation for the degradation of methylene blue was evaluated. The effect of pH, illumination time, amount of catalyst loaded, and initial dye concentration on the degradation efficiency of methylene blue was investigated. The results reveal that the optimum photocatalytic oxidation conditions of methylene blue are as follows:pH=4and illumination time is 30 min, the amount of catalyst loading is 0.075 g/L and 50 ppm methylene blue dye concentration. Under these conditions, the removal efficiency of methylene blue was 100%.
Physical Activity Advertisements That Feature Daily Well-Being Improve Autonomy and Body Image in Overweight Women but Not Men
Authors: Segar Michelle L. , Updegraff John A. , Zikmund-Fisher Brian J. , Richardson Caroline R.
Published: June 2012

The reasons for exercising that are featured in health communications brand exercise and socialize individuals about why they should be physically active. Discovering which reasons for exercising are associated with high-quality motivation and behavioral regulation is essential to promoting physical activity and weight control that can be sustained over time. This study investigates whether framing physical activity in advertisements featuring distinct types of goals differentially influences body image and behavioral regulations based on self-determination theory among overweight and obese individuals. Using a three-arm randomized trial, overweight and obese women and men (aged 40–60 yr,n=1690) read one of three ads framing physical activity as a way to achieve (1) better health, (2) weight loss, or (3) daily well-being. Framing effects were estimated in an ANOVA model with pairwise comparisons using the Bonferroni correction. This study showed that there are immediate framing effects on physical activity behavioral regulations and body image from reading a one-page advertisement about physical activity and that gender and BMI moderate these effects. Framing physical activity as a way to enhance daily well-being positively influenced participants’ perceptions about the experience of being physically active and enhanced body image among overweight women, but not men. The experiment had less impact among the obese study participants compared to those who were overweight. These findings support a growing body of research suggesting that, compared to weight loss, framing physical activity for daily well-being is a better gain-frame message for overweight women in midlife.
Guilty Molecules, Guilty Minds? The Conflicting Roles of the Innate Immune Response to Traumatic Brain Injury
Authors: Hellewell Sarah Claire , Morganti-Kossmann Maria Cristina
Published: June 2012

Traumatic brain injury (TBI) is a complex disease in the most complex organ of the body, whose victims endure lifelong debilitating physical, emotional, and psychosocial consequences. Despite advances in clinical care, there is no effective neuroprotective therapy for TBI, with almost every compound showing promise experimentally having disappointing results in the clinic. The complex and highly interrelated innate immune responses govern both the beneficial and deleterious molecular consequences of TBI and are present as an attractive therapeutic target. This paper discusses the positive, negative, and often conflicting roles of the innate immune response to TBI in both an experimental and clinical settings and highlights recent advances in the search for therapeutic candidates for the treatment of TBI.
Biomarkers of Chronic Inflammatory State in Uremia and Cardiovascular Disease
Authors: Panichi Vincenzo , Scatena Alessia , Migliori Massimiliano , Marchetti Valentina , Paoletti Sabrina , Beati Sara
Published: June 2012

Cardiovascular disease is the leading cause of death in the general population; traditional risk factors seem inadequate to explain completely the remarkable prevalence of cardiovascular mortality and morbidity observed in the uremic population. A role for chronic inflammation has been well established in the development of atherosclerotic disease, and, on the basis of these observations, atherosclerosis might be considered an inflammatory disease. Inflammation has been implicated in the etiology of coronary artery disease in the general population, and traditional inflammatory biomarkers such as C-reactive protein (CRP) and interleukin-6 (IL-6) have been shown to predict cardiovascular events in both symptomatic and asymptomatic individuals as well as those in the uremic population. Later on, new nontraditional markers were related to the risk of cardiovascular morbidity and mortality in general and in uremic population. As a consequence of the expanding research base and availability of assays, the number of inflammatory marker tests ordered by clinicians for cardiovascular disease (CVD) risk prediction has grown rapidly and several commercial assays have become available. So, up to now we can consider that several new nontraditional markers as CD40-CD40 ligand system and pentraxin-3 seem to be significant features of cardiovascular disease in general and in ESRD population.
Density-Dependent Habitat Selection in a Growing Threespine Stickleback Population
Authors: Candolin Ulrika , Selin Marita
Published: June 2012

Human-induced eutrophication has increased offspring production in a population of threespine sticklebackGasterosteus aculeatusin the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perchPerca fluviatilis(behind a transparent Plexiglas wall). However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.