bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tactile sensory system: encoding from the periphery to the cortex
Authors: Jones Lynette A. , Smith Allan M. 
Published: March 2014

AbstractSpecialized mechanoreceptors in the skin respond to mechanical deformation and provide the primary input to the tactile sensory system. Although the morphology of these receptors has been documented, there is still considerable uncertainty as to the relation between cutaneous receptor morphology and the associated physiological responses to stimulation. Labelled‐line models of somatosensory processes in which specific mechanoreceptors are associated with particular sensory qualities fail to account for the evidence showing that all types of tactile afferent units respond to a varying extent to most types of natural stimuli. Neurophysiological and psychophysical experiments have provided the framework for determining the relation between peripheral afferent or cortical activity and tactile perception. Neural codes derived from these afferent signals are evaluated in terms of their capacity to predict human perceptual performance. One particular challenge in developing models of the tactile sensory system is the dual use of sensory signals from the skin. In addition to their perceptual function they serve as inputs to the sensorimotor control system involved in manipulation. Perceptions generated through active touch differ from those resulting from passive stimulation of the skin because they are the product of self‐generated exploratory processes. Recent research in this area has highlighted the importance of shear forces in these exploratory movements and has shown that fingertip skin is particularly sensitive to shear generated during both object manipulation and tactile exploration.This article is categorized under:

Models of Systems Properties and Processes > Organismal Models
Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models
Physiology > Physiology of Model Organisms
Two Coordination Polymers with the Ligand Salicylamide: Synthesis, Crystal Structure and Luminescent Properties
Authors: Song Xueqin , Xiao Zhourong , Zhao Mengmeng , Qian Wenhui 
Published: March 2014

AbstractThe semirigid exo‐bidentate ligand 1, 4‐bis{[(2′‐picolylaminoformyl)phenoxyl]methyl}‐2, 5‐bismethylbenzene (L) was designed, synthesized, and used as building blocks for constructing luminescent lanthanide polymers. Two new lanthanide coordination polymers were characterized by elemental analysis, X‐ray diffraction analysis, and IR spectroscopy. The coordination polymers exhibit the metal‐to‐ligand molar ratio of 1:1 and the semirigid exo‐bidentate ligand bridges lanthanide nitrates forming a zigzag chain, which further interconnected to three dimensional supramolecular structure in aid of cooperative C–H···O hydrogen bonds. The luminescence properties of the europium(III) complex are discussed in detail.
Management, winter climate and plant–soil feedbacks on ski slopes: a synthesis
Authors: Meijer zu Schlochtern Melanie P. , Rixen Christian , Wipf Sonja , Cornelissen Johannes H. C. 
Published: March 2014

AbstractOwing to the increasing popularity of skiing and the upslope movement of the snow reliability line in mountain regions, more and more alpine environments are being turned into skiing areas, with strong impacts on ecosystem functions and biodiversity. Creation and management of ski slopes cause physical disturbance to soil and vegetation, while (artificial) snow supplements affect soil structure, chemistry, moisture and temperature regimes as well as shifts in snow season and growing season length. Vegetation–soil feedbacks may influence the outcome of these interactive effects on soil and vegetation, with possible consequences for soil erosion. Moreover, climate warming will lead to changing snow cover and duration, which will interact with ski slope management effects on soil and vegetation and its feedbacks. Based on a conceptual framework we review the main elements of these interactive effects on soil and vegetation on new and established ski slopes. We also set a research agenda with specific studies that could further advance our understanding of interacting ski slope management, winter climate, vegetation–soil feedbacks and ecosystem functioning. In such new investigations, alpine climate change ecology can probably learn much from the “experimental” disturbance and snow manipulations on ski slopes and vice versa.
Decolorization of Sapindus Pericarp Extract by Hydrogen Peroxide and a Comparison of Basic Characteristics Before and After Decolorization
Authors: Wang Na , Wang Heya , Weng Zhen , Zhang Cui , Wu Heng , Guo Youzhi , Sun Zhiyong , Yao Weirong 
Published: March 2014

AbstractThe saponins from the pericarps of Sapindus mukorossi Gaertn. (Sapindaceae) are attracting more and more attention because of their antimicrobial activity and their ability to act as a natural surfactant. However, the color of Sapindus pericarp extract is dark brown, which limits its application in some products. The present study aims to improve the color by adding hydrogen peroxide. An orthogonal L9 (3)4 test design was applied to optimize the decolorization parameters, including the amount of added hydrogen peroxide, time, temperature and pH. The extent of decolorization was up to 89.5 % below 80 °C within 80 min, using 2.5 % hydrogen peroxide at pH 6. The characteristics of Sapindus pericarp extract before and after bleaching were compared, including the antimicrobial and foaming performance, surface activities and detergency properties. There was no significant difference in either the diameters of the inhibition zone or the minimum inhibitory concentration against Candida albicans, Trichophyton rubrum and Pseudomonas aeruginosa (P < 0.05), while these parameters for C. albicans, T. rubrum and P. aeruginosa for the sample after decolorization were 22.33, 25.00, 15.33 mm and 0.91, 0.91, 13.03 mg/mL, respectively. The foamability of the Sapindus pericarp extract after decolorization was somewhat enhanced and the foam stability reduced (P < 0.05). There were no significant differences in values of the critical micelle concentration of the pericarp extract before and after decolorization. The detergency also remained at the same level. Our results show that the properties of the decolorized Sapindus pericarp extract were largely unchanged. This suggests that further development is worthwhile.
Attenuation of muscle wasting in murine C2C12 myotubes by epigallocatechin‐3‐gallate
Authors: Mirza Kamran A. , Pereira Suzette L. , Edens Neile K. , Tisdale Michael J. 
Published: March 2014

BackgroundLoss of muscle protein is a common feature of wasting diseases where currently treatment is limited. This study investigates the potential of epigallocatechin‐3‐gallate (EGCg), the most abundant catechin in green tea, to reverse the increased protein degradation and rescue the decreased protein synthesis which leads to muscle atrophy.MethodsStudies were conducted in vitro using murine C2C12 myotubes. Increased protein degradation and reduced rates of protein synthesis were induced by serum starvation and tumour necrosis factor‐α (TNF‐α).ResultsEGCg effectively attenuated the depression of protein synthesis and increase in protein degradation in murine myotubes at concentrations as low as 10 μM. Serum starvation increased expression of the proteasome 20S and 19S subunits, as well as the proteasome ‘chymotrypsin‐like' enzyme activity, and these were all attenuated down to basal values in the presence of EGCg. Serum starvation did not increase expression of the ubiquitin ligases MuRF1 and MAFbx, but EGCg reduced their expression below basal levels, possibly due to an increased expression of phospho Akt (pAkt) and phospho forkhead box O3a (pFoxO3a). Attenuation of protein degradation by EGCg was increased in the presence of ZnSO4, suggesting an EGCg‐Zn2+ complex may be the active species.ConclusionThe ability of EGCg to attenuate depressed protein synthesis and increase protein degradation in the myotubule model system suggests that it may be effective in preserving skeletal muscle mass in catabolic conditions.
Potential role of antimicrobial peptides in the early onset of Alzheimer's disease
Authors: Welling Mick M. , Nabuurs Rob J.A. , van der Weerd Louise 
Published: March 2014

AbstractCerebral aggregation of amyloid‐β (Aβ) is thought to play a major role in the etiology of Alzheimer's disease. Environmental influences, including chronic bacterial or viral infections, are thought to alter the permeability of the blood‐brain barrier (BBB) and thereby facilitate cerebral colonization by opportunistic pathogens. This may eventually trigger Aβ overproduction and aggregation. Host biomolecules that target and combat these pathogens, for instance, antimicrobial peptides (AMPs) such as Aβ itself, are an interesting option for the detection and diagnostic follow‐up of such cerebral infections. As part of the innate immune system, AMPs are defensive peptides that efficiently penetrate infected cells and tissues beyond many endothelial barriers, most linings, including the BBB, and overall specifically target pathogens. Based on existing literature, we postulate a role for labeled AMPs as a marker to target pathogens that play a role in the aggregation of amyloid in the brain.
Revisiting the mixing-length hypothesis in the outer part of turbulent wall layers: mean flow and wall friction
Authors: Pirozzoli Sergio 
Published: March 2014

AbstractWe reconsider foundations and implications of the mixing length theory as applied to wall-bounded turbulent flows in uniform pressure gradient. Based on recent channel-flow direct numerical simulation (DNS) data at sufficiently high Reynolds number, we find that Prandtl’s hypothesis of linear variation of the mixing length with the wall distance is rather inaccurate, hence overlap arguments are stronger in justifying the formation of a logarithmic layer in the mean velocity profile. Regarding the core region of the wall layer, we find that Clauser’s hypothesis of uniform eddy viscosity is strictly connected with the observed size of the eddy structures, and it delivers surprisingly good agreement with DNS and experiments for channels, pipes, and boundary layers. We show that the analytically derived composite mean velocity profiles can be used to accurately predict skin friction in canonical wall-bounded flows with a minimal number of adjustable parameters directly related to the mean velocity profile, and to obtain some insight into transient growth phenomena.
Similarity solution for oblique water entry of an expanding paraboloid
Authors: Wu G. X. , Sun S. L. 
Published: March 2014

AbstractSimilarity solutions based on velocity potential theory are found to be possible in the case of an expanding paraboloid entering water when gravity is ignored. Numerical solutions are obtained based on the boundary element method. Iteration is used for the nonlinear boundary conditions on the unknown free surface, together with regular remeshing. Results are obtained for paraboloids with different slenderness (or bluntness). Flow features and pressure distributions are discussed along with the physical implications. It is also concluded that similarity solutions may be possible in more general cases.
Direct numerical simulations of an inertial wave attractor in linear and nonlinear regimes
Authors: Jouve Laurène , Ogilvie Gordon I. 
Published: March 2014

AbstractIn a uniformly rotating fluid, inertial waves propagate along rays that are inclined to the rotation axis by an angle that depends on the wave frequency. In closed domains, multiple reflections from the boundaries may cause inertial waves to focus onto particular structures known as wave attractors. These attractors are likely to appear in fluid containers with at least one boundary that is neither parallel nor normal to the rotation axis. A closely related process also applies to internal gravity waves in a stably stratified fluid. Such structures have previously been studied from a theoretical point of view, in laboratory experiments, in linear numerical calculations and in some recent numerical simulations. In the present paper, two-dimensional direct numerical simulations of an inertial wave attractor are presented. By varying the amplitude at which the system is forced periodically, we are able to describe the transition between the linear and nonlinear regimes as well as the characteristic properties of the two situations. In the linear regime, we first recover the results of the linear calculations and asymptotic theory of Ogilvie (J. Fluid Mech., vol. 543, 2005, pp. 19–44) who considered a prototypical problem involving the focusing of linear internal waves into a narrow beam centred on a wave attractor in a steady state. The velocity profile of the beam and its scalings with the Ekman number, as well as the asymptotic value of the dissipation rate, are found to be in agreement with the linear theory. We also find that, as the beam builds up around the wave attractor, the power input by the applied force reaches its limiting value more rapidly than the dissipation rate, which saturates only when the beam has reached its final thickness. In the nonlinear regime, the beam is strongly affected and becomes unstable to a subharmonic instability. This instability transfers energy to secondary waves possessing shorter wavelengths and lower frequencies. The onset of the instability of a narrow inertial wave beam is investigated by means of a separate linear analysis and the results, such as the onset of the instability, are found to be consistent with the global simulations of the wave attractor. The excitation of such secondary waves described theoretically in this work has also been seen in recent laboratory experiments on internal gravity waves.
Dispersion in the large-deviation regime. Part 1: shear flows and periodic flows
Authors: Haynes P. H. , Vanneste J. 
Published: March 2014

AbstractThe dispersion of a passive scalar in a fluid through the combined action of advection and molecular diffusion is often described as a diffusive process, with an effective diffusivity that is enhanced compared with the molecular value. However, this description fails to capture the tails of the scalar concentration distribution in initial-value problems. To remedy this, we develop a large-deviation theory of scalar dispersion that provides an approximation to the scalar concentration valid at much larger distances away from the centre of mass, specifically distances that are$O(t)$rather than$O(t^{1/2})$, where$t \gg 1$is the time from the scalar release. The theory centres on the calculation of a rate function characterizing the large-time form of the scalar concentration. This function is deduced from the solution of a one-parameter family of eigenvalue problems which we derive using two alternative approaches, one asymptotic, the other probabilistic. We emphasize the connection between the large-deviation theory and the homogenization theory that is often used to compute effective diffusivities: a perturbative solution of the eigenvalue problems in the appropriate limit reduces at leading order to the cell problem of homogenization theory. We consider two classes of flows in some detail: shear flows and periodic flows with closed streamlines (cellular flows). In both cases, large deviation generalizes classical results on effective diffusivity and captures new phenomena relevant to the tails of the scalar distribution. These include approximately finite dispersion speeds arising at large Péclet number$\mathit{Pe}$(corresponding to small molecular diffusivity) and, for two-dimensional cellular flows, anisotropic dispersion. Explicit asymptotic results are obtained for shear flows in the limit of large$\mathit{Pe}$. (A companion paper, Part 2, is devoted to the large-$\mathit{Pe}$asymptotic treatment of cellular flows.) The predictions of large-deviation theory are compared with Monte Carlo simulations that estimate the tails of concentration accurately using importance sampling.
An auditory profile of sclerosteosis
Authors: Potgieter J M , Swanepoel D W , Heinze B M , Hofmeyr L M , Burger A A S , Hamersma H 
Published: March 2014

AbstractObjective:To characterise auditory involvement secondary to excessive craniotubular bone growth in individuals with sclerosteosis in South Africa.Methods:This cross-sectional study assessed the auditory profile of 10 participants with sclerosteosis. An auditory test battery was used and results for each ear were recorded using descriptive and comparative analyses.Results:All participants presented with bilateral, mixed hearing losses. Of the 20 ears, hearing loss was moderate in 5 per cent (n = 1), severe in 55 per cent (n = 11) and profound in 40 per cent (n = 8). Air–bone gaps were smaller in older participants, although the difference was not statistically significant (p > 0.05). Computed tomography scans indicated pervasive abnormalities of the external auditory canal, tympanic membrane, middle-ear space, ossicles, oval window, round window and internal auditory canal. Narrowed internal auditory canals corresponded to poor speech discrimination, indicative of retrocochlear pathology and absent auditory brainstem response waves.Conclusion:Progressive abnormal bone formation in sclerosteosis involves the middle ear, the round and oval windows of the cochlea, and the internal auditory canal. The condition compromises conductive, sensory and neural auditory pathways, which results in moderate to profound, mixed hearing loss.
Dynamic rolling analysis of triangular-bipyramid robot
Authors: Tian Yaobin , Yao Yan-An 
Published: March 2014

SUMMARYIn this paper a rolling robot resembling the shape of a triangular-bipyramid is proposed. The robot has three degrees of freedom and is formed by connecting two tripod mechanisms with three spherical joints. By kinematic analysis, the robot can be viewed as a planar four-bar linkage. Further, its dynamic rolling ability is discussed by Zero Moment Point (ZMP) analysis. We show that the robot has the capability to roll, adjust its step length, and switch rolling directions. These functions are verified by a series of simulations with a CAD (computer-aided design) model and experiments with a prototype.
Eliminating Extreme Inequality: A Sustainable Development Goal, 2015–2030
Authors: Doyle Michael W. , Stiglitz Joseph E. 
Published: March 2014

At the United Nations Millennium Summit in September 2000, UN member states took a dramatic step by putting people rather than states at the center of the UN's agenda. In their Millennium Declaration, the assembled world leaders agreed to a set of breathtakingly broad goals touching on peace through development, the environment, human rights, the protection of the vulnerable, the special needs of Africa, and reforms of UN institutions. Particularly influential was the codification of the Declaration's development-related objectives, which emerged in the summer of 2001 as the now familiar eight Millennium Development Goals (MDGs), to be realized by 2015.
Coalitions of the Willing and Responsibilities to Protect: Informal Associations, Enhanced Capacities, and Shared Moral Burdens
Authors: Erskine Toni 
Published: March 2014

“Coalition of the willing” is a phrase that we hear invoked with frequency in world politics. Significantly, it is generally accompanied by claims to moral responsibility. Yet the label commonly used to connote a temporary, purpose-driven, self-selected collection of states sits uneasily alongside these assertions of moral responsibility.This article explores how the informal nature of such associations should inform judgments of moral responsibility. I begin by briefly recounting what I call a model of institutional moral agency in order to explain why it seems theoretically and practically problematic to talk about the moral responsibilities of informal associations. I then focus on coalitions of the willing as prominent, and challenging, examples of such associations, before raising misgivings about my own rather stark distinction if it means that accounts of moral responsibility must be reduced to the members—or potential members—of such coalitions in a way that neglects the moral significance of their acting together. Prompted by these concerns, I explore arguments by Virginia Held and Larry May about moral responsibility in relation to informal associations and identify insights that can be taken from these positions to refine our expectations and evaluations of the actions associated with such collectivities. Finally, I consider the particular implications of these insights in relation to the widely espoused duty to intervene to rescue vulnerable populations.
Streptococcus pneumoniaeserogroup 6 clones over two decades
Authors: PAYNE D. B. , GRAY B. M. 
Published: March 2014

SUMMARYThe major evolutionary stresses onStreptococcus pneumoniaeare thought to be the widespread use of antibiotics and the deployment of effective vaccines against the capsular polysaccharides. Our current knowledge of genetic lineages among pneumococcal isolates comes largely from investigations just before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) introduced in 2000. We examined 66 serogroup 6 isolates from the 1970s, long before the introduction of PCV7 and before widespread penicillin resistance was common in Birmingham, Alabama, to look for ancestors of the clones that came into play around the introduction of the PCV7 vaccine. The hypothesis was that some clonal complexes, if not individual clones, would be stable enough to persist over this period of time. We compared the 1970s isolates with 122 isolates from the 1990s in US and worldwide collections. Genotyping with pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) revealed that while some clones were probably localized to our area, others have persisted within groups that have expanded or diminished over the years.
A study of learners’ perceptions of online intercultural exchange through Web 2.0 technologies
Authors: Lee Lina , Markey Alfred 
Published: March 2014

AbstractThis paper reports a Spanish-American telecollaborative project through which students usedTwitter, blogs and podcasts for intercultural exchange over the course of one semester. The paper outlines the methodology for the project including pedagogical objectives, task design, selection of web tools and implementation. Using qualitative and quantitative data collection, the study explored how the application of Web 2.0 facilitated cross-cultural communication. How the use of digital technology affected the way in which the students viewed intercultural learning and peer feedback was examined. The findings showed that students viewed the online exchange as a superb venue for intercultural communication with native speakers. Through social engagements, students not only gained cultural knowledge but also became more aware of their own beliefs and attitudes toward their own culture. In addition, discussions on topics of tangible and intangible cultures afforded the opportunity to raise students’ awareness of cultural norms and practices. Peer feedback helped learners increase lexical knowledge, prevent language fossilization, and acquire native-sounding discourse. The study suggests that allocating sufficient time to complete each task and making personal commitment to online contributions are essential to successful intercultural exchanges.