bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operant conditioning of the tibialis anterior motor evoked potential in people with and without chronic incomplete spinal cord injury
Authors: Thompson Aiko K. , Cote Rachel H. , Sniffen Janice M. , Brangaccio Jodi A. 
Published: September 2018

The activity of corticospinal pathways is important in movement control, and its plasticity is essential for motor skill learning and re-learning after central nervous system (CNS) injuries. Therefore, enhancing the corticospinal function may improve motor function recovery after CNS injuries. Operant conditioning of stimulus-induced muscle responses (e.g., reflexes) is known to induce the targeted plasticity in a targeted pathway. Thus, an operant conditioning protocol to target the corticospinal pathways may be able to enhance the corticospinal function. To test this possibility, we investigated whether operant conditioning of the tibialis anterior (TA) motor evoked potential (MEP) to transcranial magnetic stimulation can enhance corticospinal excitability in people with and without chronic incomplete spinal cord injury (SCI). The protocol consisted of 6 baseline and 24 up-conditioning/control sessions over 10 wk. In all sessions, TA MEPs were elicited at 10% above active MEP threshold while the sitting participant provided a fixed preset level of TA background electromyographic activity. During baseline sessions, MEPs were simply measured. During conditioning trials of the conditioning sessions, the participant was encouraged to increase MEP and was given immediate feedback indicating whether MEP size was above a criterion. In 5/8 participants without SCI and 9/10 with SCI, over 24 up-conditioning sessions, MEP size increased significantly to ~150% of the baseline value, whereas the silent period (SP) duration decreased by ~20%. In a control group of participants without SCI, neither MEP nor SP changed. These results indicate that MEP up-conditioning can facilitate corticospinal excitation, which is essential for enhancing motor function recovery after SCI.NEW & NOTEWORTHY We investigated whether operant conditioning of the motor evoked potential (MEP) to transcranial magnetic stimulation can systematically increase corticospinal excitability for the ankle dorsiflexor tibialis anterior (TA) in people with and without chronic incomplete spinal cord injury. We found that up-conditioning can increase the TA MEP while reducing the accompanying silent period (SP) duration. These findings suggest that MEP up-conditioning produces the facilitation of corticospinal excitation as targeted, whereas it suppresses inhibitory mechanisms reflected in SP.
Cortico-cerebellar network involved in saccade adaptation
Authors: Guillaume Alain , Fuller Jason R. , Srimal Riju , Curtis Clayton E. 
Published: September 2018

Saccade adaptation is the learning process that ensures that vision and saccades remain calibrated. The central nervous system network involved in these adaptive processes remains unclear because of difficulties in isolating the learning process from the correlated visual and motor processes. Here we imaged the human brain during a novel saccade adaptation paradigm that allowed us to isolate neural signals involved in learning independent of the changes in the amplitude of corrective saccades usually correlated with adaptation. We show that the changes in activation in the ipsiversive cerebellar vermis that track adaptation are not driven by the changes in corrective saccades and thus provide critical supporting evidence for previous findings. Similarly, we find that activation in the dorsomedial wall of the contraversive precuneus mirrors the pattern found in the cerebellum. Finally, we identify dorsolateral and dorsomedial cortical areas in the frontal and parietal lobes that encode the retinal errors following inaccurate saccades used to drive recalibration. Together, these data identify a distributed network of cerebellar and cortical areas and their specific roles in oculomotor learning. NEW & NOTEWORTHY The central nervous system constantly learns from errors and adapts to keep visual targets and saccades in registration. We imaged the human brain while the gain of saccades adapted to a visual target that was displaced while the eye was in motion, inducing retinal error. Activity in the cerebellum and precuneus tracked learning, whereas parts of the dorsolateral and dorsomedial frontal and parietal cortex encoded the retinal error used to drive learning.
Effects of Supplemental Calcium and Vitamin D on Expression of Toll-Like Receptors and Phospho-IKKα/β in the Normal Rectal Mucosa of Colorectal Adenoma Patients
Authors: Hodge Rebecca , Mandle Hannah B. , Ray Stephen , Tandon Sonia , Peterson Meaghan , Henry Abigail , Jahan Ferdous A. , Bostick Roberd M. , Baron John A. , Barry Elizabeth L. , Yacoub Rami , Rutherford Robin E. , Seabrook March E. , Fedirko Veronika 
Published: September 2018

Abstract
Chronic inflammation in the colorectum, a significant contributor to colorectal carcinogenesis, can be triggered by the activation of proinflammatory signaling pathways such as those initiated by Toll-like receptors (TLR) and nuclear factor κB (NF-κB). Although experimental evidence supports calcium and vitamin D potentially modifying these proinflammatory pathways in the colorectum, human data in these regards are scarce. We investigated supplemental calcium (1,200 mg daily) and/or vitamin D3 (1,000 IU daily) effects on inflammatory signaling pathway-related biomarkers in a subset of 105 participants from a colorectal adenoma recurrence chemoprevention clinical trial. We assessed expression of TLR4 and TLR5, which recognize the bacterial components lipopolysaccharides and flagellin, respectively, and phospho-IKKα/β (pIKKα/β), a biomarker of inflammation, in the normal-appearing rectal crypt epithelium and stroma using standardized, automated immunohistochemistry and quantitative image analysis. Following 1 year of treatment, TLR4, TLR5, and pIKKα/β expression in the rectal mucosa did not statistically significantly change with vitamin D or calcium supplementation, taken alone or in combination. Several baseline participant characteristics, including body mass index, history of sessile serrated adenomas, high red/processed meat intake, and high levels of rectal epithelial cell proliferation (as measured by MIB-1/Ki-67), were associated with higher baseline expression of TLRs or pIKKα/β. Our findings suggest that vitamin D and calcium may have no substantial effect on the investigated biomarkers. However, several modifiable lifestyle factors may be associated with TLRs and pIKKα/β expression in the normal rectal mucosa, supporting their future investigation as potentially treatable, preneoplastic risk factors for colorectal neoplasms. Cancer Prev Res; 11(11); 707–16. ©2018 AACR.
Repeatability of combat rate across different group compositions in male house finches
Authors: Hasegawa Masaru , Giraudeau Mathieu , Ligon Russell A. , Kutsukake Nobuyuki , Watanabe Mamoru , McGraw Kevin J. 
Published: September 2018

AbstractStudies of animal contests have focused on the probability of winning an encounter, because it directly affects the benefits of competition. However, the costs (e.g., physiological stress) and benefits of competition should also depend on the number of aggressive encounters per unit time (combat rate, hereafter) in which the focal individual is involved. Using colourful and drab male house finches (Haemorhous mexicanus) from urban and rural sites, we showed that combat rate was repeatable across the same and different group sizes for birds who won competitions. In addition, colourful urban males exhibited the lowest propensity for frequent aggression (and hence low combat rate). However, male bill size (another trait we previously found to correlate with male competitiveness in this species) was not related to aggressive propensity. Combat rate can be predicted by male identity and some, but not all, predictors of male competitiveness.
Near-Storm Environments of Outbreak and Isolated Tornadoes
Authors: Anderson-Frey Alexandra K. , Richardson Yvette P. , Dean Andrew R. , Thompson Richard L. , Smith Bryan T. 
Published: September 2018

AbstractBetween 2003 and 2015, there were 5343 outbreak tornadoes and 9389 isolated tornadoes reported in the continental United States. Here, the near-storm environmental parameter-space distributions of these two categories are compared via kernel density estimation, and the seasonal, diurnal, and geographical features of near-storm environments of these two sets of events are compared via self-organizing maps (SOMs). Outbreak tornadoes in a given geographical region tend to be characterized by greater 0–1-km storm-relative helicity and 0–6-km vector shear magnitude than isolated tornadoes in the same geographical region and also have considerably higher tornado warning-based probability of detection (POD) than isolated tornadoes. A SOM of isolated tornadoes highlights that isolated tornadoes with higher POD also tend to feature higher values of the significant tornado parameter (STP), regardless of the specific shape of the area of STP. For a SOM of outbreak tornadoes, when two outbreak environments with similarly high magnitudes but different patterns of STP are compared, the difference is primarily geographical, with one environment dominated by Great Plains and Midwest outbreaks and another dominated by outbreaks in the southeastern United States. Two specific tornado outbreaks are featured, and the events are placed into their climatological context with more nuance than typical single proximity sounding-based approaches would allow.
Clozapine attenuates mitochondrial burdens and abnormal behaviors elicited by phencyclidine in mice via inhibition of p47phox; Possible involvements of phosphoinositide 3-kinase/Akt signaling
Authors: Tran Hai-Quyen , Park Se J , Shin Eun-Joo , Tran The-Vinh , Sharma Naveen , Lee Yu J , Jeong Ji H , Jang Choon-Gon , Kim Dae-Joong , Nabeshima Toshitaka , Kim Hyoung-Chun 
Published: September 2018

Background: Oxidative stress and mitochondrial dysfunction have been implicated in the pathophysiology of schizophrenia. Aims: We investigated whether antipsychotic clozapine modulates nicotinamide adenine dinucleotide phosphate oxidase and mitochondrial burdens induced by phencyclidine in mice. Methods: We examined the effect of clozapine on nicotinamide adenine dinucleotide phosphate oxidase activation, mitochondrial burdens (i.e. oxidative stress and mitochondrial dysfunction), and activities of enzymatic antioxidant in the prefrontal cortex, and subsequent abnormal behaviors induced by repeated treatment with phencyclidine. p47 phox Knockout mice and LY294002, a phosphoinositide 3-kinase inhibitor, were employed to elucidate the pharmacological mechanism of clozapine. Results: Phencyclidine treatment resulted in an early increase nicotinamide adenine dinucleotide phosphate oxidase activity, membrane translocation of p47 phox, interaction between p-Akt and p47 phox, and mitochondrial burdens in wild-type mice. Although these increases returned to near control level four days post-phencyclidine, mitochondrial superoxide dismutase and glutathione peroxidase activities were decreased at that time. Clozapine, LY294002, or p47 phox knockout significantly ameliorated social withdrawal and recognition memory deficits produced by phencyclidine. Importantly, LY294002 did not significantly alter the effects of clozapine against abnormal behaviors and the interaction between p-Akt and p47 phox induced by phencyclidine. Furthermore, neither LY294002 nor clozapine exhibited any additive effects to the protection afforded by p47 phox knockout against phencyclidine insult. Conclusion: Our results suggest that p47 phox gene mediates phencyclidine-induced mitochondrial burdens and abnormal behaviors, and that the interactive modulation between p47 phox and phosphoinositide 3-kinase/Akt is important for the understanding on the pharmacological mechanism of clozapine.
Preform Technology: A Necessary Requirement for Quality Controlled LCM-Processes
Authors: Mitschang P. , Ogale A. , Schlimbach J. , Weyrauch F. , Weimer C. 
Published: September 2018

A considerable number of process versions of Liquid Composite Moulding (LCM) technologies have been commercialised during the last few years. Only recently there have been attempts to reduce costs and to implement more complex components by the application of preform technology. This article indicates the most appropriate application fields for LCM techniques for the manufacture of fibre reinforced polymers. Different LCM methods are described and summarised. The preforming techniques and particularly the sew -and -cut philosophy for developing a tailored reinforcement is explained. Investigations designed to elucidate the influence of sewing parameters and thread properties have led to an understanding of the requirements and preform characteristics needed to operate the quality controlled LCM process. Some concepts related to the control of the resin injection are described, and a realization of a decision-tree-concept is shown. Finally, a comparison of cost effects for different preforming methods shows a need to define a “critical preforming effort” to manufacture quality components as well as economically optimised parts.
Morphology, Crystalline Structure and Isothermal Crystallization Kinetics of Polybutylene Terephthalate/Montmorillonite Nanocomposites
Authors: Wu Defeng , Zhou Chixing , Fan Xie , Mao Dalian , Bian Zhang 
Published: September 2018

The melt intercalation method was employed to prepare poly(butylene terepathalate)/montmorillonite nanocomposites, and their microstructure was characterized by wide angle X-ray diffraction and transmission electron microscopy. The XRD results showed that the crystalline plane such as (010), (111), (100) was smaller than that of pristine PBT, which indicates that the crystallite size of PBT in the nanocomposites could be diminished by adding clay. Moreover, the isothermal crystallization kinetics of PBT and PBT/MMT nanocomposites was investigated by differential scanning calorimetry (DSC). During isothermal crystallization, the development of crystallinity with time was analysed by the Avrami equation. The results show that very small amounts of clay dramatically increased the rate of crystallization and high clay concentrations reduced the rate of crystallization at the low crystallization temperatures. At low concentrations of clay, the distance between dispersed platelets was large so it was relatively easy for the additional nucleation sites to incorporate surrounding polymer, and the crystal nucleus was formatted easily. However, at high concentrations of clay, the diffusion of polymer chains to the growing crystallites was hindered by large clay particles, despite the formation of additional nucleation sites by the clay layers. At the higher crystallization temperature, the crystallization of the nanocomposites was slower than that of the pure PBT under the experimental conditions, which means that with the increase in chains mobility at the high crystallization temperature, the crystal nuclei are harder to format, and the hindering effect of clay particles on the polymer chains was stronger than the nucleating effect of the layers. In addition, the activation energies of crystallization for PBT and its nanocomposites were calculated by the Arrhenius relationship, and the results showed that the nanocomposites with a low clay content had the lower activation energy values than PBT, while high amounts of clay increased the activation energy of PBT.
Surface Modification of PBO Fibres by Gamma-Ray Irradiation: Effects on Interfacial Properties of their Epoxy Composites
Authors: Zhang C.H. , Huang Y.D. , Liu L. 
Published: September 2018

The surfaces of poly [p-phenylene benzobisoxazole] (PBO) fibres were grafted with epichlorohydrin by a gamma (γ)-ray irradiation method. The influence of irrdiation dose on the interfacial shear strength (IFSS), interlaminar shear strength (ILSS) and the fibre wettability were investigated. In addition, the fibre surface composition, and the shear fracture topography of PBO fibre/epoxy resin composites were analysed by X–ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The results indicate that a dose of 30KGy was the optimal condition for PBO fibre surface modification. The oxygen content of the irradiated PBO fibres was 22% higher than that of the untreated ones, and chlorine atoms were introduced onto the surface of the fibres through grafting actions between epichlorohydrin and PBO. The wettability of the epichlorohydrin-grafted PBO fibres was significantly increased, and the values of IFSS and ILSS of its composites were increased by 70% and 135%, respectively. SEM shows that the improved interfacial adhesion resulted in a change in the failure mode of PBO fibre/epoxy composite from an adhesive-type interfacial failure to a cohesive-like matrix failure.
Effect of Tetradecyl Methyl Acrylate-Maleic Anhydride Copolymer on the Mechanical Properties of Glass Mat Reinforced Polypropylene Composites
Authors: Zhou Shanhua , Xu Zhiyu , Liu Xin , Gao Yan , Dong Qingzhi 
Published: September 2018

A new interfacial modifier made of tetradecyl methylacrylate-maleic anhydride copolymer (TMA- co-MAH) was prepared and characterized. The effect of reaction time and monomer ratio on the gross conversion and MAH content in the copolymer was studied. When the glass mat was treated with TMA- co-MAH solutions and compounded with PP, the MAH group of the interfacial modifier formed strong interactions with the glass mat and the long side chain of the interfacial modifier entangled firmly with the polypropylene matrix. In comparison with maleated polyolefins, the higher MAH content of the TMA- co-MAH resulted in better interfacial adhesion between the PP and the glass mat resulting in increased flexural strength and modulus, and the ductility of the TMA- co-MAH introduced a ductile interlayer into the interface of the glass mat reinforced polypropylene composites (GMT-PPs) to achieve higher impact strength. Therefore the mechanical properties of composites treated with TMA- co-MAH were all superior to those of GMT-PPs treated with maleic anhydride grafted polypropylene (PP- g-MAH) solutions when they were used at the same level. The effects of anhydride content, concentration of copolymer and compounding time on the mechanical property of GMT-PPs were investigated. With the optimal monomer ratio, MAH:TMA = 7:3, a 3% copolymer solution and a compounding time of 5 min, the impact strength, flexural strength and modulus of GMT-PPs treated with the new interfacial modifier were all improved significantly compared with composites treated with 0.3% PP- g-MAH solution.
Combined Effect of Nano-clay and Nano-carbon Black on Properties of NR Nanocomposites
Authors: Qing-xiu Jia , You-ping Wu , Ping Xiang , Xin Ye , Yi-qing Wang , Li-qun Zhang 
Published: September 2018

Natural rubber (NR)/clay/carbon black nanocomposites, filled with 10 phr, 20 phr, and 30 phr of filler (in total) were obtained by adding carbon black (N330) on a two-roll mill to NR/clay nano-compounds prepared by the emulsion compounding method. X-ray diffraction patterns and transmission electron microscope photographs of the nanocomposites showed that both fillers were dispersed randomly in the NR matrix at nano-scale and that the space between the clay layers was filled with carbon black particles. At the same total filler loadings, the mechanical properties of the naocomposites filled with both clay and carbon black, such as moduli at 100% and 300% elongation, tensile strength and tear strength, were greatly improved compared with those of either NR/clay nanocomposites or NR/carbon black nanocomposites. This indicates that the samples with both fillers possessed excellent mechanical properties. It was found that the NR/clay/carbon black nanocomposites retained advantages from both fillers, for example, the processability and dynamic properties were close to those of NR/carbon black nanocomposites, and the gas barrier properties were almost as good as those of NR/clay nanocomposites.
The Preparation of Core/Shell Particles with Siloxane in the Shell
Authors: Cao Shunsheng , Deng Xiaobo , Liu Bailing 
Published: September 2018

Core-shell microspheres ranging in average diameter from 12.829 to 15.039 μm, with a poly butyl methacrylate (BMA) core, and a poly 3-(methacryloxypropyl)-trimethoxysilane (MATS) shell, were prepared with methanol as the dispersion medium, by a successive seeding method under kinetically controlled conditions. To date, although some of particles (PSi/PA) have been prepared by seeded emulsion polymerisation, only a few core/shell (PA/PSi) microspheres have been reported the literatures. To prepare core/shell (PA/PSi), the core was first synthesized by dispersion polymerisation and to form seeds; addition of MATS monomer was started after 90~95% conversion of the BMA. The reaction was prolonged for another 12 h to achieve complete consumption of MATS monomer. Microspheres; containing hydrophilic PBMA as the core and hydrophobic PMATS as the shell, were successfully formed through the free radical of surface in the core. The particles morphology and size distribution were examined using a Transmission electron microscope and a Malvern Master Sizer/E particle size analyser, respectively.
Viscoelastic Constitutive Model of Unvulcanized Rubber
Authors: Yong Li , Jing'an Wu , Xingwen Du 
Published: September 2018

Based on rheological test results, a new viscoelastic constitutive equation for unvulcanized rubber has been set up, with mathematical justification to describe its mechanical properties in relation to the yield stress and shear-thinning effect. In this model, every term or coefficient has an explicit physical meaning. The proposed model indicates that the yield stress is one of the main causes for the shear-thinning effect and reveals why some materials possess double-Newtonian regions with the shear viscosity in the first region higher than that in the second region. The yield stress makes the flow index of the power law fluid model vary widely, so that it needs to be eliminated from the power law fluid model. The model can also distinguish the true shear viscosity from the apparent shear viscosity effectively. The parameters of the equation are determined by the step fitting method, which is the precondition for quantitative analysis. However, the equation is a one-dimensional model, so further research is needed.
Preparation and Properties of Thermoplastic Polyamide-imide and Polyurea-amide-imide/Copper Foil Composites
Authors: Huang Meng-Shun , Yang Ming-Chien , Chou Shen 
Published: September 2018

Polyamide-imide (PAI) and polyurea-amide-imide (PUAI) resins were polymerized from five reactants: 4,4'-oxydianiline, 4-nitrobenzoyl chloride, 4,4'-diphenylmethane diisocyanate, 1,2,4,5-benzenetetracarboxylic dianhydride, and 3,3'-4,4'-benzophenone tetracarboxylic dianhydride. Their chemical structures were characterized using elemental analysis, FTIR and 1H NMR spectroscopy. Their thermal properties, adhesive properties, electrical properties, heat resistance, and chemical resistance were studied. The experimental results show that the glass transition temperatures of PAI and PUAI films occurred respectively at 360 °C and 229 °C, and the 10% weight loss occurred respectively at approximately 481 °C and 420 °C. The optimal hot-press conditions for PAI/copper foil (CU) composite were 380°C and 4.90 MPa, whereas those for PUAI/copper foil (CU) composites were 250 °C and 4.90 MPa. Values of the peel strength, dielectric constant, and dissipation factor were obtained and the peel strength was re-measured after a thermal stability test. The chemical resistance tests showed that the peel strength retention values of the PAI/CU and PUAI/CU composites were respectively more than 95% and more than 94% after immersing in 10% H2SO4 solution at 70 °C for 1 h.