bluuebunny/crossref_metadata_2025 huggingface dataset:
The SKG Mutation in ZAP‐70 also Confers Arthritis Susceptibility in C57 Black Mouse Strains
Authors: Guerard S. , Boieri M. , Hultqvist M. , Holmdahl R. , Wing K.
Published: April 2016

Various rodent models of arthritis are essential to dissect the full complexity of human rheumatoid arthritis (RA), a common autoimmune disease affecting joints. The SKG model of arthritis originates from a spontaneous mutation in ZAP‐70 found in a BALB/c colony. This mutation affects T cell selection due to reduced TCR signalling, which allows leakage of self‐reactive T cells from the thymus. To further expand the practical applicability of this unique model in arthritis research, we investigated the arthritogenicity of the SKG mutation in two common black mouse strains C57BL/6.Q and C57BL/10.Q and compared to BALB/c.Q. Mice retained the reduced TCR signalling characteristic of SKG.BALB/c mice, which leads to similar alteration in thymic selection. Importantly, mice also retained susceptibility to chronic arthritis after a single injection of mannan from Saccharomyces cerevisiae, with comparable prevalence and severity regardless of the genetic background. Further characterization of CD4+ T cells revealed a similar bias towards IL‐17 production and activated T cell phenotype in all SKG strains compared to respective wild type controls. Finally, transfer of SKG thymocytes conferred susceptibility to recipients, which confirm the intrinsic defect and pathogenicity of T cells. Overall, these results underline the strong impact that the W163C ZAP‐70 mutation has on T cell‐driven arthritis, and they support the use of the SKG model in black mice, which is useful for further investigations of this distinctive arthritis model to better understand autoimmunity.
Distinguishing the subjective and the objective aspects of self‐concept clarity
Authors: Guerrettaz Jean , Arkin Robert M.
Published: April 2016

Since its introduction, self‐concept clarity has been viewed as a construct related to the structure and organization of a person's self‐concept. We argue, however, that self‐concept clarity may best be understood as a combination of subjective, metacognitive beliefs about the self‐concept and objective structure and organization. We consider the unique influences of both objective and subjective clarity and offer some suggestions and novel hypotheses for investigating this proposed distinction.
Enhancing the Conceptualization and Measurement of Implicit and Explicit Affective Evaluations: A Case Study in Disordered Eating
Authors: Woodward Halley E. , Cameron C. Daryl , Treat Teresa A.
Published: April 2016

Affective evaluations (i.e., evaluations of affectively evocative stimuli) play important roles in many behaviors, including clinically relevant behaviors like disordered eating. Understanding automatic and controlled affective evaluations can enhance prediction and treatment of more deliberate versus more impulsive clinical behaviors, respectively. However, methodological and theoretical shortcomings cloud the implicit affective evaluation literature, particularly as applied in clinical psychology. This article aims to improve the clinical science of implicit and explicit affective evaluation by capitalizing on theoretical and methodological advancements drawn from implicit social cognition. We recommend three key enhancements to the affective evaluation literature: improve the structural comparability between indirect and direct measures, assess evaluations on both valence and arousal dimensions of affect, and carefully characterize and select stimuli. Additional improvements to analytic approaches (e.g., mixed effects modeling and process dissociation) are also recommended. Such efforts will advance our theoretical understanding of the relative contributions of automatic and controlled processes to clinically relevant affective evaluation, thereby informing assessment and improving intervention. Applying advanced methodologies of implicit cognition to clinical phenomena will also reiterate and reinforce the use of these advances in social psychology.
The Visual Guide to Morality: Vision as an Integrative Analogy for Moral Experience, Variability and Mechanism
Authors: Schein Chelsea , Hester Neil , Gray Kurt
Published: April 2016

Analogies help organize, communicate and reveal scientific phenomena. Vision may be the best analogy for understanding moral judgment. Although moral psychology has long noted similarities between seeing and judging, we systematically review the “morality is like vision” analogy through three elements: experience, variability and mechanism. Both vision and morality are experienced as automatic, durable and objective. However, despite feelings of objectivity, both vision and morality show substantial variability across biology, culture and situation. The paradox of objective experience and cultural subjectivity is best understood through constructionism, as both vision and morality involve the flexible combination of more basic ingredients. Specifically, both vision and morality involve a mechanism that demonstrates Gestalt, combination and coherence. The “morality is like vision” analogy not only provides intuitive organization and compelling communication for moral psychology but also speaks to debates in the field, such as intuition versus reason, pluralism versus universalism and modularity versus constructionism.
Gondwana breakup: no evidence for a Davie Fracture Zone offshore northern Mozambique, Tanzania and Kenya
Authors: Klimke Jennifer , Franke Dieter
Published: April 2016

Plate tectonic reconstructions assume a major inactive transform fault, the Davie Fracture Zone, in the West Somali Basin, along which Madagascar is thought to have migrated southwards following Gondwana breakup in the Mesozoic. Based on the interpretation of reflection seismic data, we show that the Walu Ridge offshore Kenya and the Kerimbas Basin offshore northern Mozambique are tectonically unrelated to the southward motion of Madagascar and correlate with Late Cretaceous volcanism and inversion in Kenya and the evolution of the East African Rift System respectively. Offshore Tanzania, geophysical data do not show basement structures indicating the presence of a major transform fault. These results challenge the commonly supported transform margin concept and imply a more southerly pre‐breakup position of Madagascar within Gondwana. Opening of the West Somali Basin by SW‐propagating oblique rifting and seafloor spreading is proposed.
Blood graft cellular composition and posttransplant outcomes in myeloma patients mobilized with or without low‐dose cyclophosphamide: a randomized comparison
Authors: Valtola Jaakko , Silvennoinen Raija , Ropponen Antti , Siitonen Timo , Säily Marjaana , Sankelo Marja , Terävä Venla , Putkonen Mervi , Kuittinen Taru , Pelkonen Jukka , Mäntymaa Pentti , Remes Kari , Varmavuo Ville , Jantunen Esa
Published: April 2016

BACKGROUND

Autologous stem cell transplantation is a standard treatment in multiple myeloma (MM). Blood grafts are usually collected after mobilization with granulocyte–colony‐stimulating factor (G‐CSF) alone or in a combination with cyclophosphamide (CY). There is limited knowledge of the possible effects of different mobilization regimens on blood graft characteristics and posttransplant outcomes.

STUDY DESIGN AND METHODS

Thirty‐eight patients with MM were included in this study. The patients were randomly assigned at registration to mobilization with either low‐dose CY plus G‐CSF (Arm A) or G‐CSF alone (Arm B) and received three cycles of lenalidomide, bortetzomib, and dexamethasone induction. Flow cytometry analysis of lymphocyte subsets in the blood grafts after cryopreservation was performed. Hematologic and immune recovery were evaluated up to 12 months posttransplant.

RESULTS

The blood grafts in Arm A contained significantly more CD34+ cells but in Arm B there was a greater proportion of CD34+CD38– cells and higher numbers of T and B lymphocytes as well as natural killer (NK) cells. The engraftment was comparable but lymphocyte count at 15 days posttransplant was higher in Arm B (0.8 × 109/L vs. 0.5 × 109/L, p = 0.033). At 3 and 6 months posttransplant the total number of NK cells was also higher in G‐CSF–mobilized patients. There was no difference in progression‐free survival between the study arms.

CONCLUSION

CY plus G‐GSF yields more CD34+ cells but seems to diminish lymphocyte and NK cell counts in the grafts and hampers immune recovery after transplantation. Thus G‐CSF alone might be a preferred mobilization method due to more rapid immune recovery posttransplant.
ADAMTS13 autoantibodies cloned from patients with acquired thrombotic thrombocytopenic purpura: 1. Structural and functional characterization in vitro
Authors: Ostertag Eric M. , Kacir Stephen , Thiboutot Michelle , Gulendran Gayathri , Zheng X. Long , Cines Douglas B. , Siegel Don L.
Published: April 2016

BACKGROUND

Acquired thrombotic thrombocytopenia purpura (TTP) is a life‐threatening illness caused by autoantibodies that decrease the activity of ADAMTS13, the von Willebrand factor–cleaving protease. Despite efficacy of plasma exchange, mortality remains high and relapse is common. Improved therapies may come from understanding the diversity of pathogenic autoantibodies on a molecular or genetic level. Cloning comprehensive repertoires of patient autoantibodies can provide the necessary tools for studying immunobiology of disease and developing animal models.

STUDY DESIGN AND METHODS

Anti‐ADAMTS13 antibodies were cloned from four patients with acquired TTP using phage display and characterized with respect to genetic origin, inhibition of ADAMTS13 proteolytic activity, and epitope specificity. Anti‐idiotypic antisera raised to a subset of autoantibodies enabled comparison of their relatedness to each other and to polyclonal immunoglobulin (Ig)G in patient plasma.

RESULTS

Fifty‐one unique antibodies were isolated comprising epitope specificities resembling the diversity found in circulating patient IgG. Antibodies directed both to the amino terminal domains and to those requiring the ADAMTS13 cysteine‐rich/spacer region for binding inhibited proteolytic activity, while those solely targeting carboxy‐terminal domains were noninhibitory. Anti‐idiotypic antisera raised to a subset of antibody clones crossreacted with and reduced the inhibitory activity of polyclonal IgG from a set of unrelated patients.

CONCLUSIONS

Anti‐ADAMTS13 autoantibodies isolated by repertoire cloning display the diversity of epitope specificities found in patient plasma and provide tools for developing animal models of acquired TTP. Shared idiotypes of inhibitory clones with circulating IgG from multiple patients suggest common features of pathogenic autoantibodies that could be exploited for developing more targeted therapies.
Clearance of stored red blood cells is not increased compared with fresh red blood cells in a human endotoxemia model
Authors: Peters Anna L. , Beuger Boukje , Mock Donald M. , Widness John A. , de Korte Dirk , Juffermans Nicole P. , Vlaar Alexander P.J. , van Bruggen Robin
Published: April 2016

BACKGROUND

It is thought that the clearance of transfused red blood cells (RBCs) is related both to the storage time of the transfusion product and to the inflammatory status of the recipient. We investigated these effects in a randomized, “two‐hit,” healthy volunteer transfusion model, comparing autologous RBCs that were stored for 35 days with those that were stored for 2 days.

STUDY DESIGN AND METHODS

Healthy male volunteers donated 1 unit of autologous RBCs either 2 days (2D) or 35 days (35D) before the study date. The experiment was started by infusion of 2 ng/kg lipopolysaccharide (“first hit”). Two hours later, the stored RBCs (“second hit”) were reinfused, followed by the labeling of RBCs with biotin. Clearance of biotin‐labeled RBCs (BioRBCs) was measured during the 5‐hour posttransfusion endotoxemia period along with measurements of phosphatidylserine (PS) exposure, lactadherin binding, and expression of CD47 (cluster of differentiation 47; a transmembrane protein encoded by the CD47 gene).

RESULTS

In the 2D stored RBCs group, 1.5% ± 3.4% of infused BioRBCs were cleared from the circulation 5 hours posttransfusion versus 4.8% ± 4.0% in the 35D stored RBCs group (p = 0.1). There were no differences in PS exposure, lactadherin binding, or CD47 expression between fresh and stored RBCs or between pretransfusion and posttransfusion measurements.

CONCLUSION

Our study shows a low clearance of RBCs even during endotoxemia. Furthermore, short‐term clearance of BioRBCs during endotoxemia was not related to storage duration. Consistent with these observations, PS exposure, lactadherin binding, and CD47 expression did not differ between 2D and 35D stored cells before or after transfusion. We conclude that, in the presence of endotoxemia, clearance of 35D stored autologous RBCs is not increased compared with 2D stored fresh RBCs.
Quality of Adhesions After Sutured Paramedian vs. Laparoscopic Toggle Abomasopexy in an Ovine Model
Authors: Thomas Keri L. , Wilson David G. , Bracamonte José L. , Carmalt James L. , Luby Christopher D.
Published: April 2016

Objective

To evaluate adhesions created by abomasopexies using either chromic gut or polydioxanone suture through a right paramedian approach and determine whether a laparoscopic toggle technique is an acceptable alternative to open abomasopexy using an ovine model.

Study Design

Experimental study.

Animals

Mature ewes (n=30).

Methods

Ewes received 1 of 3 abomasopexy techniques (n=10): right paramedian approach using chromic gut or polydioxanone, or a laparoscopic toggle technique. After euthanasia 8 weeks postoperatively, adhesions were removed en bloc and adhesion cross‐sectional area (width × length) and depth (distance from abdominal wall to abomasum) were measured and given a grade of 0–3 based on the quality of adhesion. Surgical time was recorded and compared for each technique. Significance was set atP≤.05.

Results

Abomasopexies performed with either suture material resulted in a significantly larger mean cross‐sectional area and higher adhesion grades compared to those performed using the toggle. Width and length of adhesions formed using chromic gut or polydioxanone were not significantly different; however, both were significantly wider and longer than those formed using the toggle. The laparoscopic toggle technique required significantly less surgical time than the sutured techniques.

Conclusion

Polydioxanone is as effective as chromic gut suture material in inducing abomasal adhesion formation in our sheep model. The clinical significance of the size and grade of adhesions formed is unknown and requires further investigation before the laparoscopic toggle technique can be recommended as a replacement for paramedian abomasopexy in cattle for the treatment of displaced abomasum.
Modular elliptic curves over the field of twelfth roots of unity
Authors: Jones Andrew
Published: April 2016

In this paper we perform an extensive study of the spaces of automorphic forms for $\text{GL}_{2}$ of weight $2$ and level $\mathfrak{n}$, for $\mathfrak{n}$ an ideal in the ring of integers of the quartic CM field $\mathbb{Q}({\it\zeta}_{12})$ of twelfth roots of unity. This study is conducted through the computation of the Hecke module $H^{\ast }({\rm\Gamma}_{0}(\mathfrak{n}),\mathbb{C})$, and the corresponding Hecke action. Combining this Hecke data with the Faltings–Serre method for proving equivalence of Galois representations, we are able to provide the first known examples of modular elliptic curves over this field.

Supplementary materials are available with this article.
Zooming in on the genesis of atherosclerotic plaque microcalcifications
Authors: Ruiz Jessica L. , Weinbaum Sheldon , Aikawa Elena , Hutcheson Joshua D.
Published: April 2016

Epidemiological evidence conclusively demonstrates that calcium burden is a significant predictor of cardiovascular morbidity and mortality; however, the underlying mechanisms remain largely unknown. These observations have challenged the previously held notion that calcification serves to stabilize the atherosclerotic plaque. Recent studies have shown that microcalcifications that form within the fibrous cap of the plaques lead to the accrual of plaque‐destabilizing mechanical stress. Given the association between calcification morphology and cardiovascular outcomes, it is important to understand the mechanisms leading to calcific mineral deposition and growth from the earliest stages. We highlight the open questions in the field of cardiovascular calcification and include a review of the proposed mechanisms involved in extracellular vesicle‐mediated mineral deposition.

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Visualization of Headlight Illumination for the Virtual Prototyping of Light-Based Driver–Assistance Systems
Authors: Berssenbrügge Jan , Trächtler Ansgar , Schmidt Christoph
Published: April 2016

Driving simulators that are capable of simulating a virtual drive at night are increasingly used for the virtual prototyping of light-based driver–assistance systems (DAS). Here, the interplay between driver and assistance system, which enhances the illumination of the road ahead of the vehicle, is investigated. For such investigations, special driving simulators are applied that not only enable a standard driving simulation but also cover the special requirements for the visualization of a driving scenery at night, the simulation of automotive headlights during a virtual drive at night, and the interface to a headlight control module (HCM) that operates the physical headlight prototypes. In this paper, we present the visualization system of the reconfigurable driving simulator from the research project TRAFFIS. We describe the special application focus on the virtual prototyping of a light-based DAS from our project partner Varroc Lighting Systems. The light-based DAS is based on a headlight prototype that combines a glare-free high-beam (GFHB) function and a predictive adaptive frontlighting system (PAFS) for glare-free driving with maximized headlight time.
Risk-Based Path Planning Optimization Methods for Unmanned Aerial Vehicles Over Inhabited Areas1
Authors: Rudnick-Cohen Eliot , Herrmann Jeffrey W. , Azarm Shapour
Published: April 2016

Operating unmanned aerial vehicles (UAVs) over inhabited areas requires mitigating the risk to persons on the ground. Because the risk depends upon the flight path, UAV operators need approaches that can find low-risk flight paths between the mission's start and finish points. Because the flight paths with the lowest risk could be excessively long and indirect, UAV operators are concerned about the tradeoff between risk and flight time. This paper presents a risk assessment technique and bi-objective optimization methods to find low-risk and time (flight path) solutions and computational experiments to evaluate the relative performance of the methods (their computation time and solution quality). The methods were a network optimization approach that constructed a graph for the problem and used that to generate initial solutions that were then improved by a local approach and a greedy approach and a fourth method that did not use the network solutions. The approaches that improved the solutions generated by the network optimization step performed better than the optimization approach that did not use the network solutions.
An Ordinary Differential Equation Formulation for Multibody Dynamics: Holonomic Constraints
Authors: Haug Edward J.
Published: April 2016

A method is presented for formulating and numerically integrating ordinary differential equations (ODEs) of motion for holonomically constrained multibody systems. Tangent space coordinates are defined as independent generalized coordinates that serve as state variables in the formulation, yielding ODEs of motion. Orthogonal dependent coordinates are used to enforce kinematic constraints at position, velocity, and acceleration levels. Criteria that assure accuracy of constraint satisfaction and well conditioning of the reduced mass matrix in the equations of motion are used as the basis for redefining local coordinates on the constraint manifold, as needed, transparent to the user and at minimal computational cost. The formulation is developed for holonomically constrained multibody models that are based on essentially any form of generalized coordinates. A spinning top with Euler parameter orientation coordinates is used as a model problem to analytically reduce Euler's equations of motion to ODEs. Numerical results using a fourth-order Nystrom integrator verify that accurate results are obtained, satisfying position, velocity, and acceleration constraints to computer precision. A computational algorithm for implementing the approach with state-of-the-art explicit numerical integrators is presented and used in solution of three examples, one planar and two spatial. Performance of the method in satisfying all three forms of kinematic constraint, based on error tolerances embedded in the formulation, is verified.
The Theoretical Measure of the Ductility of Failure for All Isotropic Materials in All States of Stress1
Authors: Christensen Richard M.
Published: April 2016

The ductile/brittle failure theory for homogeneous and isotropic materials is extended to give a rational and mathematically rigorous measure for the ductility of failure. This new failure number methodology is completely developed and proved to be valid and general. It applies to all isotropic materials as subjected to any and all states of stress. Not only does the failure theory predict the safety or failure for any given stress state, it then projects the quantitative ductility level for the failure stress state. Many important examples are given with detailed interpretations of the results and with guides for general usage.
Dexterous Grasping Tasks Generated With an Add-on End Effector of a Haptic Feedback System
Authors: Leon Jean-Claude , Dupeux Thomas , Chardonnet Jean-Rémy , Perret Jérôme
Published: April 2016

The simulation of grasping operations in virtual reality (VR) is required for many applications, especially in the domain of industrial product design, but it is very difficult to achieve without any haptic feedback. Force feedback on the fingers can be provided by a hand exoskeleton, but such a device is very complex, invasive, and costly. In this paper, we present a new device, called HaptiHand, which provides position and force input as well as haptic output for four fingers in a noninvasive way, and is mounted on a standard force-feedback arm. The device incorporates four independent modules, one for each finger, inside an ergonomic shape, allowing the user to generate a wide range of virtual hand configurations to grasp naturally an object. It is also possible to reconfigure the virtual finger positions when holding an object. The paper explains how the device is used to control a virtual hand in order to perform dexterous grasping operations. The structure of the HaptiHand is described through the major technical solutions required and tests of key functions serve as validation process for some key requirements. Also, an effective grasping task illustrates some capabilities of the HaptiHand.
The Combined Effects of an Upstream Ramp and Swirling Coolant Flow on Film Cooling Characteristics
Authors: Yang Wenshuo , Pu Jian , Wang Jianhua
Published: April 2016

This paper presents an experimental investigation on the performances of a new film cooling structure design, in which a ramp is placed upstream of a cylindrical film hole and a cylindrical cavity with two diagonal impingement holes is set at the inlet of the film hole to generate a swirling coolant flow entering the film hole. The experiments are carried out by two undisturbed measurement techniques, planar laser induced fluorescence (PLIF) and time-resolved particle image velocimetry (TR-PIV) in a water tunnel. The effects of the upstream ramp angle, blowing ratio (BR), and coolant impingement angle on the film cooling performances of a flat plate are studied at three ramp angles (0 deg, 15 deg, and 25 deg), two coolant swirling directions (clockwise and counterclockwise), two impingement angles (15 deg and 30 deg), and three BRs (0.6, 1.0, and 1.4). The experimental results show that at high BRs, the combination structures of the upstream ramp with the swirling coolant flow generated by the impingement angles can significantly improve film cooling performances; the best combination is at a 30 deg impingement angle and a 25 deg ramp angle. This can be explained by the fact that the swirling flow is significantly pressed on to the wall by means of the upstream ramp. Using the analogous analysis of heat and mass transfer, the adiabatic film effectiveness averaged over a cross section is obtained; the analysis indicates that at high BRs, the combined effect of a ramp with a large angle of 25 deg with 30 deg impingement angle can increase the film effectiveness up to 30% when compared to the test case without a ramp at the exit of the film hole. The images captured by PLIF exhibit an interesting phenomenon, i.e., the swirling of the coolant in different directions can influence the counter vortex pair (CVP) in rotating layers, and the coolant swirling in a clockwise direction enhances the right mixing of the CVP with coolant ejection, whereas the coolant swirling in a counterclockwise direction enhances the left-mixing of the CVP with coolant ejection.
Primary proximal epithelioid sarcoma of the lung successfully treated with pneumonectomy and adjuvant chemotherapy
Authors: Saha Debjit , Basu Arnab , Maiti Abhishek , Rodriguez Estelamari
Published: April 2016

Primary sarcomas of the lung and proximal epithelial sarcomas (PESs) are extremely rare. Inactivation of INI1 has been found in the majority of epithelioid sarcoma (ES). We report the third known case of a primary PES of the lung along with immunohistochemical data. A 41-year-old man with HIV infection, on highly active antiretroviral therapy, presented with haemoptysis, shortness of breath and progressive weight loss for 2 months. He was eventually diagnosed with stage IIA cT2bN0M0 grade-2 primary PES of the lung. This patient underwent pneumonectomy and adjuvant chemotherapy with ifosfamide and doxorubicin. He remains in remission 36 months since diagnosis. Our case stands to help other clinicians as treatment of such rare cases is often reliant on case reports. We also posit a possible pathogenic mechanism given a history of HIV infection in this patient. The association of INI1 mutation with other atypical sarcomas in patients with HIV infection merits further evaluation.
Middle lobe syndrome: a singularly rare presentation of complicated pulmonary hydatid disease
Authors: Kunal Shekhar , Pilaniya Vikas , Shah Ashok
Published: April 2016

Imaging is crucial to the diagnosis of pulmonary hydatid disease, as it is often the first modality that raises suspicion of the disease. Middle lobe syndrome (MLS) as a presentation of this disease is a distinct rarity. A 45-year-old woman, a never-smoker, presented with cough and streaky haemoptysis. Imaging demonstrated a trapezoidal opacity with its base towards the hilum and contiguous with the right cardiac border. The reformatted sagittal view confirmed the diagnosis of MLS. Fibreoptic bronchoscopy (FOB) revealed an avascular white membranous structure wholly occluding the medial segment of the middle lobe. This was completely removed through gentle suction. Bronchial aspirate revealed hooklets of hydatid and echinococcal serology was positive. Subsequently, three cycles of albendazole were administered with remarkable clinical and radiological improvement. To the best of our knowledge, this is the first detailed description of MLS caused by pulmonary hydatidosis that was completely removed through FOB.
Above- and below-ground community structure of ectomycorrhizal fungi in three Norway spruce (Picea abies) stands in Switzerland
Authors: Peter Martina , Ayer François , Egli Simon , Honegger Rosmarie
Published: April 2016

The structure of ectomycorrhizal communities was assessed above- and below-ground at three different sites in Switzerland that are dominated by Norway spruce (Picea abies (L.) Karst.). We applied three different approaches to record the ectomycorrhizal species compositions and their spatial structures and compared them among each other. Sporocarp inventories were carried out weekly for 3 years. Belowground, molecular, and morphological analyses of ectomycorrhizal roots were performed. In the 3 years of sporocarp survey, a total of 128 ectomycorrhizal species was observed. Most abundant in number of species were the genera Cortinarius and Russula in all three sites. Using polymerase chain reaction, only 22% of the ectomycorrhizal species observed in sporocarp surveys were detected in mycorrhizas. Species that produce no or inconspicuous sporocarps were most abundant on the root system in all three study sites. The resolution was clearly inferior in morphotype compared with molecular analyses. Spatial analyses of the ectomycorrhizal species composition among subplots revealed high variability within sites. Within sites, spatial structure with positive autocorrelation was observed based on sporocarp data as well as molecular analyses of root tips at the site where the number of analysed mycorrhizas was sufficiently high. No spatial structure could be detected on this scale by morphotype analyses because of the high variability among soil cores. All three methods showed the same site to be separated from the other two based on ectomycorrhizal species compositions. Stand ages and their histories are discussed as possible explanations for these findings.Key words: community structure, ectomycorrhiza, macrofungi, morphotype, ITS RFLP, Picea abies.
Space use and its effects on reproductive success of anadromous Atlantic salmon
Authors: Tentelier Cédric , Larranaga Nicolas , Lepais Olivier , Manicki Aurélie , Rives Jacques , Lange Frédéric
Published: April 2016

We combined habitat mapping, radio tracking of adults, redd mapping, and genetic parentage analysis on juveniles for 2 consecutive years to test eight predictions on the reproductive payoffs and individual features associated with space use tactics of anadromous Atlantic salmon (Salmo salar) in a natural population. Regarding payoffs, we found that (1) males settled in better habitat, visited more redds, and tended to get more mates than males settled in poorer habitat; (2) they also sired more offspring; (3) the latter effect was stronger in the first year, when redds were more aggregated; and (4) female reproductive success increased with habitat quality in their home range, especially in the first year. For individual features, (5) individuals that settled earlier in their home range had better habitat for juvenile production, but only in the first year; (6) females were less mobile than males, especially in the second year; (7) larger males did not settle in better habitats than smaller males; and (8) smaller males were not more mobile than larger males.
A non-commutative framework for topological insulators
Authors: Bourne C. , Carey A. L. , Rennie A.
Published: April 2016

We study topological insulators, regarded as physical systems giving rise to topological invariants determined by symmetries both linear and anti-linear. Our perspective is that of non-commutative index theory of operator algebras. In particular, we formulate the index problems using Kasparov theory, both complex and real. We show that the periodic table of topological insulators and superconductors can be realized as a real or complex index pairing of a Kasparov module capturing internal symmetries of the Hamiltonian with a spectral triple encoding the geometry of the sample’s (possibly non-commutative) Brillouin zone.
Improved lattice Boltzmann model for multi-component diffusion flow with large pressure difference
Authors: Liu Fu-Min , Wang An-Lin , Qiu Ruo-Fan , Jiang Tao
Published: April 2016

The pseudopotential lattice Boltzmann model has been widely used to solve multi-phase and multi-component flow problems. However, original pseudopotential model cannot be used in simulating diffusion flow with large pressure difference because of its limitation. In this paper, we incorporate pseudopotential model with a new form of effective mass to solve this problem based on the relationship between pressure difference and effective mass. The improved model is verified through Laplace’s law and binary immiscible Poiseuille flow. By simulating pipeline binary diffusion flow and two-inlet binary cavity jet flow, we show that the improved model can achieve larger pressure difference than pseudopotential model with traditional effective mass forms.
On several static cylindrically symmetric solutions of the Einstein equations
Authors: Grigoryev Sergey , Leonov Arkadiy
Published: April 2016

We study the Einstein equations in the static cylindrically symmetric case with the stress–energy tensor of the form [Formula: see text], where [Formula: see text] is an unknown function and [Formula: see text], [Formula: see text], [Formula: see text] are arbitrary real constants ([Formula: see text] is assumed to be nonzero). The stress–energy tensor of this form includes as special cases several well-known solutions, such as the perfect fluid solution with the barotropic equation of state, the solution with the static electric field and the solution with the massless scalar field. We solve the Einstein equations with this stress–energy tensor and study some properties of the obtained metric.
Modified Fermi energy of electrons in a superhigh magnetic field
Authors: Zhu Cui , Gao Zhi Fu , Li Xiang Dong , Wang Na , Yuan Jian Ping , Peng Qiu He
Published: April 2016

In this paper, we investigate the electron Landau level stability and its influence on the electron Fermi energy, [Formula: see text], in the circumstance of magnetars, which are powered by magnetic field energy. In a magnetar, the Landau levels of degenerate and relativistic electrons are strongly quantized. A new quantity [Formula: see text], the electron Landau level stability coefficient is introduced. According to the requirement that [Formula: see text] decreases with increasing the magnetic field intensity [Formula: see text], the magnetic field index [Formula: see text] in the expression of [Formula: see text] must be positive. By introducing the Dirac-[Formula: see text] function, we deduce a general formulae for the Fermi energy of degenerate and relativistic electrons, and obtain a particular solution to [Formula: see text] in a superhigh magnetic field (SMF). This solution has a low magnetic field index of [Formula: see text], compared with the previous one, and works when [Formula: see text] and [Formula: see text] Gauss. By modifying the phase space of relativistic electrons, a SMF can enhance the electron number density [Formula: see text], and decrease the maximum of electron Landau level number, which results in a redistribution of electrons. According to Pauli exclusion principle, the degenerate electrons will fill quantum states from the lowest Landau level to the highest Landau level. As [Formula: see text] increases, more and more electrons will occupy higher Landau levels, though [Formula: see text] decreases with the Landau level number [Formula: see text]. The enhanced [Formula: see text] in a SMF means an increase in the electron Fermi energy and an increase in the electron degeneracy pressure. The results are expected to facilitate the study of the weak-interaction processes inside neutron stars and the magnetic-thermal evolution mechanism for magnetars.
About the diffusion mechanism in the silica liquid
Authors: Nhan N. T. T. , Kien P. H. , Hung P. K. , Hong N. V. , San L. T.
Published: April 2016

In this paper, we have numerically studied the diffusion mechanism in silica liquid based on the idea that the collective movement of particles is controlled by reactions [Formula: see text] and [Formula: see text]. Four models at temperatures from 2600 K to 3500 K have been constructed by molecular dynamic simulation. The simulation shows that the liquid has a small amount of defect-cells which are of importance for the diffusion. In particular, the majority of reactions happen via defect-cells SiO5 and OSi3. Moreover, the defect-cells do not uniformly distribute in the liquid, but they have a tendency to locate nearby forming large cluster. Further, it is revealed that the spatial distribution of reactions is heterogeneous. We found two distinct clusters. First cluster (none-reaction cluster) consists of particles on which no reaction happens. The second cluster (reaction cluster) includes particles where the reactions happen. The size of clusters found is dependent with temperature and diffusion time. Moreover, the mobility of particles in none-reaction cluster is significantly smaller than in reaction cluster. This indicates the dynamics heterogeneity in the liquid. We suggest that the dynamics slowdown is originated from the percolation of none-reaction cluster.
An Inference Methodology for Selecting and Clustering Genes Based on Likelihood Ratio Test
Authors: Liu Ruiyin , Tao Jian , Wang Dehui
Published: April 2016

Peddada et al. (Gene selected and clustering for time-course and close-response microarray experiments using order-restricted inference, Bioinformatics 19 (2003): 834–841) proposed a new method for selecting and clustering genes according to their time-course or dose-response profiles. Their method necessitates the assumption of a constant variance through time or among dosages. This homoscedasticity assumption is, however, seldom satisfied in practice. In this paper, via the application of Shi’s algorithms and a modified bootstrap procedure (N. Z. Shi, Maximum likelihood estimation of means and variances from normal populations under simulations order restrictions (J. Multivariate Anal. 50 (1994) 282–293), we proposed a generalized order-restricted inference method which releases the homoscedasticity restriction. Simulation results show that procedures considered in this paper as well as those by Peddada et al. (Gene selected and clustering for time-course and close-response microarray experiments using order-restricted inference, Bioinformatics 19 (2003) 834–841) are generally comparable in terms of Type I error rate while our proposed algorithms are usually more powerful.
Study of 242−248Cm isotopes in the projected shell model framework
Authors: Sadiq Saiqa , Devi Rani , Khosa S. K.
Published: April 2016

The projected shell model framework is employed to study the band spectra in [Formula: see text]Cm isotopes. The present calculations reproduce the available experimental data on the yrast bands. Besides this, B(E2) transition probabilities of even–even Cm isotopes have also been calculated. The low spin states of yrast band are seen to arise purely from zero-quasi-particle (o-qp) intrinsic states whereas the high spin states have multi-quasi-particle structure. For the odd-neutron (odd-[Formula: see text]) isotopes, the calculated results qualitatively reproduce the available data on ground and lowest excited state bands for [Formula: see text]Cm. However, for [Formula: see text]Cm the negative-parity ground state band is in reasonable agreement with the experimental data.
Thermal two-neutron separation energy in the case of Erbium isotopes
Authors: Kadi H. , Benhamouda N.
Published: April 2016

We propose to study the thermal two-neutron separation energy in the case of Erbium isotopes: 80 ≤ N ≤ 108. In this aim, one used the finite temperature Bardeen Cooper Schrieffer (FTBCS) method where the statistical fluctuations are treated as a part of Landau prescription. The behavior of this quantity according to the neutron number and temperature provides indication about the nuclear shape transition, and disappearance of shell effects. The obtained results allow to show that the inclusion of statistical fluctuations in the calculation have a nonnegligible effect. Indeed, the fact that this kind of fluctuations effect is important at high temperatures induces a smooth decrease of pairing gap parameter. As a consequence, the persistence of pairing effect at high temperature leads a change on the shell effect. Indeed, when statistical fluctuations are considered, the shell effect persists at high temperature which is not the case of the usual FTBCS approach.
Parameter Identification for Nonlinear Structures by a Constrained Kalman Filter with Limited Input Information
Authors: Ding Y. , Guo L. N. , Zhao B. Y.
Published: April 2016

In this study, a new structural identification method is proposed to simultaneously evaluate the parameter and partial external excitation. The external excitation is decomposed as the linear combination of orthogonal bases, by which the problem of time-variant excitation identification is transformed into the identification of constant decomposition coefficients. A new constrained unscented Kalman filter (UKF) is proposed to identify the structural parameters and coefficients of excitation decomposition based only on measurement of the acceleration response. The proposed filter can retain the physical meaning of the structural parameters identified. A three-storey hysteretic nonlinear shear building is investigated numerically. The structural parameter and external force can be accurately identified with the proposed filter. The results of the simulation studies using the constrained UKF are compared with those from the conventional UKF. It is shown that some parameters identified by the conventional UKF may lose physical meaning, while the proposed constrained UKF can retain physical meaning. In the presence of measurement noise, the structural parameters and dynamic load can still be accurately identified using the proposed constrained UKF, which indicates the stability of the identification process.
Ambidexterity and Ambiguity: The Link Between Ambiguity Management and Contextual Ambidexterity in Innovation
Authors: Brun Eric Christian
Published: April 2016

The research goal of this paper is to explore and explain the relation between ambiguity management and contextual ambidexterity in innovation. Based on qualitative analysis of case data, a model is presented showing how managing ambiguity is an underlying process of contextual ambidexterity. Requisite variety, perspective-taking and interpretive skills help generate ambiguity to achieve exploration, while analytic skills help reduce ambiguity to achieve exploitation. Contextual ambidexterity is achieved through a process of alternating between generation, sustention and reduction of ambiguity. High ambiguity tolerance (AT) emphasizes exploration, while low AT emphasizes exploitation. The findings contribute to a more detailed theoretical understanding of the contextual ambidexterity concept and can help practitioners to achieve contextual ambidexterity in their innovation projects.
Quantum chaos inside space-temporal Sinai billiards
Authors: Addazi Andrea
Published: April 2016

We discuss general aspects of non-relativistic quantum chaos theory of scattering of a quantum particle on a system of a large number of naked singularities. We define such a system space-temporal Sinai billiard. We discuss the problem in semiclassical approach. We show that in semiclassical regime the formation of trapped periodic semiclassical orbits inside the system is unavoidable. This leads to general expression of survival probabilities and scattering time delays, expanded to the chaotic Pollicott–Ruelle resonances. Finally, we comment on possible generalizations of these aspects to relativistic quantum field theory.
Hierarchical Beam Finite Elements Based Upon a Variables Separation Method
Authors: Giunta Gaetano , Belouettar Salim , Polit Olivier , Gallimard Laurent , Vidal Philippe , D’ottavio Michele
Published: April 2016

A family of hierarchical one-dimensional beam finite elements developed within a variables separation framework is presented. A Proper Generalized Decomposition (PGD) is used to divide the global three-dimensional problem into two coupled ones: one defined on the cross-section space (beam modeling kinematic approximation) and one belonging to the axis space (finite element solution). The displacements over the cross-section are approximated via a Unified Formulation (UF). A Lagrangian approximation is used along the beam axis. The resulting problems size is smaller than that of the classical equivalent finite element solution. The approach is, then, particularly attractive for higher-order beam models and refined axial meshes. The numerical investigations show that the proposed method yields accurate yet computationally affordable three-dimensional displacement and stress fields solutions.
Microstructure tailoring in nanostructured thermoelectric materials
Authors: Jiang Qinghui , Yang Junyou , Liu Yong , He Hongcai
Published: April 2016

Progresses in thermoelectric (TE) materials will contribute to solving the world’s demands for energy and global climate protection. It also calls for higher ZT to achieve ideal commercial conversion efficiency. As an effective way, nanostructuring can reduce the thermal conductivity by the selective scattering of phonons or enhance Seebeck coefficient via modification of the density of the states, resulting in good ZT value. Meanwhile, TE properties of nanostructured materials should depend on the size and morphology of the microstructure features. This review emphasizes the developments in the TE bulk materials at the nanoscale in the past several years and summarizes the understanding in this active field.
MAPS – A Magic Angle Positioning System for Enhanced Imaging in High-Field Small-Bore MRI
Authors: Squires Alexander , Chan Kevin C. , Ho Leon C. , Sigal Ian A. , Jan Ning-Jiun , Tse Zion Tsz Ho
Published: April 2016

The “magic angle” MRI effect can enhance signal intensity in aligned collagenous structures oriented at approximately 55[Formula: see text] with respect to the main magnetic field. The difficulty of positioning tissue inside closed-bore scanners has hampered magic angle use in research and clinics. An MRI-conditional mechatronic system has been developed to control sample orientation inside a 9.4T small bore MRI scanner. The system orients samples to within 0.5[Formula: see text] and enables a 600% increase in tendon signal intensity.
Ground-penetrating radar stratigraphy and dynamics of megaflood gravel dunes
Authors: Carling Paul A , Bristow Charles S. , Litvinov Alexey S.
Published: April 2016

Ground-penetrating radar was used to elucidate the stratigraphy of late Pleistocene gravel dunes in the Altai Mountains of southern Siberia that formed when a lake emptied as a result of ice-dam failure. Survey-lines across dunes had a resolution of decimetres, with depth penetration of 20 m. The reflections identify bounding surfaces and radar facies. Two classes of unconformities are identified: (1) an erosional unconformity at the base of the dunes; (2) steeply inclined unconformities that truncate underlying inclined reflections and are downlapped by overlying inclined reflections within the dunes. Unconformities define six radar facies (RF): RF 1, basal subhorizontal discordant reflections; RF 2, poorly defined discordant reflections; RF 3, planar inclined reflections; RF 4, sigmoidal inclined reflections; RF 5, trough fills; RF 6, low-angle inclined reflections. The basal unconformity represents the flood-cut surface, across which the dunes migrated. The inclined unconformities may be interpreted in two ways: (1) erosional surfaces induced by unsteady flow within one flood, or (2) erosional surfaces developed by a series of floods reactivating dunes left stranded by previous floods. The evidence favours the latter model, which is consistent with the occurrence of several dune-forming events within the basin. The broader implications of the study are considered with respect to investigations of megaflood bedforms worldwide.