Depletion of cortical norepinephrine in rats by 6-hydroxydopamine does not impair performance of a delayed-nonmatching-to-sample task.

Rats were trained on a spatial delayed-nonmatching-to-sample (DNMTS) task, matched for performance, and randomly assigned to treatment with dorsal noradrenergic bundle injections of either 6-hydroxydopamine, to deplete cortical norepinephrine (NE), or vehicle, to control for the effects of surgery. After recovery, there were no significant differences between the groups when retrained on the DNMTS task at retention intervals (RIs) from 0.1 to 15.0 sec. Furthermore, no differences were observed when rats were trained at a 6.0-sec RI filled with distracting stimuli or when dummy information runs were added to increase proactive interference. These results demonstrate that depletion of cortical NE cannot account for the DNMTS performance deficits observed in rats recovered from pyrithiamine-induced thiamine deficiency (R. L. Knoth and R. G. Mair, 1991; J. K. Robinson and Mair, 1992). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ten-year clinical assessment of three posterior resin composites and two amalgams

OBJECTIVE: The long-term clinical performance of three posterior resin composites and two amalgams was assessed. METHOD AND MATERIALS: Thirty Class II restorations each of P-30, Occlusin, Clearfil Posterior (composites), New True Dentalloy, and Solila Nova (amalgams) were placed. Reviews took place at 6 months and at 1, 2, 3, 4, 5, and 10 years. At each visit the gingival condition, the contact point status, and the presence of ledges, gaps, or recurrent caries were assessed. The color match, cavosurface marginal stain, general surface stain, tarnish, and corrosion were also scored where applicable. Epoxy resin replicas were used to measure the maximum depth of wear. RESULTS: After 10 years, there had been corrosion of both the high- and low-copper amalgams and a slight deterioration in color match of a number of composite restorations. Eighteen (of 20) Occlusin restorations had obvious cavosurface marginal stain, attributed to staining of the unfilled bonding resin layer. Statistical analysis indicated that New True Dentalloy, Solila Nova, and Clearfil-P exhibited significantly less wear than Occlusin and P-30. None of the restorations examined at the 10-year recall required replacement. CONCLUSION: The five materials, placed in a dental school environment, provided adequate clinical service for 10 years.     

Robust self-stabilizing weight-based clustering algorithm

Ad hoc networks consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. Such networks cannot rely on centralized and organized network management. The clustering problem consists of partitioning network nodes into non-overlapping groups called clusters. Clusters give a hierarchical organization to the network that facilitates network management and that increases its scalability.In a weight-based clustering algorithm, the clusterheads are selected according to their weight (a node’s parameter). The higher the weight of a node, the more suitable this node is for the role of clusterhead. In ad hoc networks, the amount of bandwidth, memory space or battery power of a node could be used to determine weight values.A self-stabilizing algorithm, regardless of the initial system configuration, converges to legitimate configurations without external intervention. Due to this property, self-stabilizing algorithms tolerate transient faults and they are adaptive to any topology change.In this paper, we present a robust self-stabilizing weight-based clustering algorithm for ad hoc networks. The robustness property guarantees that, starting from an arbitrary configuration, after one asynchronous round, the network is partitioned into clusters. After that, the network stays partitioned during the convergence phase toward a legitimate configuration where the clusters verify the “ad hoc clustering properties”.     

GIS-based applications of sensitivity analysis for sewer models

Sensitivity analysis (SA) evaluates the impact of changes in model parameters on model predictions. Such an analysis is commonly used when developing or applying environmental models to improve the understanding of underlying system behaviours and the impact and interactions of model parameters. The novelty of this paper is a geo-referenced visualization of sensitivity indices for model parameters in a combined sewer model using geographic information system (GIS) software. The result is a collection of maps for each analysis, where sensitivity indices (calculated for model parameters of interest) are illustrated according to a predefined symbology. In this paper, four types of maps (an uncertainty map, calibration map, vulnerability map, and design map) are created for an example case study. This article highlights the advantages and limitations of GIS-based SA of sewer models. The conclusion shows that for all analyzed applications, GIS-based SA is useful for analyzing, discussing and interpreting the model parameter sensitivity and its spatial dimension. The method can lead to a comprehensive view of the sewer system.     

Involvement of Ventral Pallidum in Prefrontal Cortex-Dependent Aspects of Spatial Working Memory.

Ventral pallidum (VP) is an important source of limbic input to medial thalamus. Three studies examined the role of VP in spatial memory tasks impaired by medial thalamic lesions. In the 1st study, rats with VP lesions were impaired performing delayed matching trained with retractable levers (DMRL), a measure sensitive to prefrontal (but not hippocampal) damage. The 2nd study demonstrated dose-dependent DMRL impairment following microinjection of gamma-aminobutyric acidA, glutamate, or mu-opioid agonists in VP. In the 3rd study, VP lesions had no effect on varying choice radial-maze delayed nonmatching, a measure sensitive to hippocampal (but not prefrontal) lesions. These results suggest a common role in spatial memory for VP and other components of prefrontal-ventral striatopallidothalamic circuits distinct from hippocampal function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut fu?r Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s(-1). Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s(-1) and with diameters of between 0.05 μm and 5 μm. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and is controlled remotely by a custom, platform independent, software package. The new control instrumentation and electronics, together with the wide range of accelerable particle types, allow the controlled investigation of hypervelocity impact phenomena across a hitherto unobtainable range of impact parameters.     

Mechanical properties of continuous bamboo fiber-reinforced biobased polyamide 11 composites

This study is devoted to the analysis of the properties of continuous bamboo fiber (BF)-reinforced polyamide 11 (PA 11) composites. The SEM observations highlighted continuity between BFs and the polymeric matrix showing a high density of hydrogen bonds. The comparative calorimetric study of the matrix and its composites showed that the crystallinity of PA 11 was not modified by the presence of bamboo fibers. The physical aging observed in PA 11 is no more observed in composites due to physical interactions between PA 11 and BFs. The mechanical properties were investigated by tensile strength and dynamic mechanical analysis. The introduction of BFs enhanced Young's modulus of the matrix by a factor of 10. The presence of BFs also improved the storage shear modulus G′ over the whole temperature range. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47623.     

Regulations and research on RC&S for hydrogen storage relevant to transport and vehicle issues with special focus on composite containments

Developers interested in high pressure storage of hydrogen for mobile use increasingly rely on composite cylinders for onboard storage or transport of dangerous goods. Thus, composite materials and systems deserve special consideration. History gives interesting background information important to the understanding of the current situation as to regulations, codes and standards.     

Influence of new thermoplastic sizing agents on the mechanical behavior of poly(ether ketone ketone)/carbon fiber composites

In this study, unidirectional poly(ether ether ketone)/carbon fiber (CF) composite sheets were elaborated with unsized, epoxy‐sized, and thermoplastic‐sized CFs by hot‐press molding. The thermoplastic sizings that we used were poly(ether imide) (PEI) and poly(ether ketone ketone) oligomer aqueous dispersions. Scanning electron microscopy observation of the composites freeze fractures showed that unlike unsized or epoxy‐sized CFs, the thermoplastic sizings improved the interaction between the fibers and the matrix. A comparative study of the mechanical relaxations by dynamic mechanical analysis was carried out on the different composites before and after immersion in kerosene. At low temperature, the PEI sizing had a significant influence on the β relaxation, particularly after kerosene immersion. The thermoplastic sizings did not modify the glass‐transition temperature but improved the kerosene resistance on the composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42550.