Glutamate receptor-mediated restoration of experience-dependent place field expansion plasticity in aged rats.

Place fields of hippocampal pyramidal cells expand asymmetrically when adult rats repeatedly follow the same route. This behaviorally induced expression of neuronal plasticity uses an NMDAR-dependent, LTP-like mechanism and could be used by hippocampal networks to store information. Aged spatial memory-impaired rats exhibit defective experience-dependent place field expansion plasticity. One possible explanation for this aged-associated deficit is alterations in glutamatergic function. In fact, both NMDAR- and AMPAR-mediated field excitatory postsynaptic potentials in CA1 decrease with aging. The current study investigated whether modulation of either AMPA or NDMA receptor activity could restore this experience-dependent plasticity by prolonging AMPAR activity with the ampakine CX516 and modulating the NMDAR with the noncompetitive antagonist memantine. The spatial firing characteristics of multiple CA1 pyramidal cells were monitored under both treatment conditions as aged rats repeatedly traversed a circular track. Compared to the saline baseline condition, acute administration of memantine, but not CX516, reinstated experience-dependent place field expansion. Taken together, these data suggest that pharmacological manipulation of the NMDAR can improve the function of hippocampal networks critical to optimal cognition in aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences methods for randomized experiments.

Experiments allow researchers to randomly vary the key manipulation, the instruments of measurement, and the sequences of the measurements and manipulations across participants. To date, however, the advantages of randomized experiments to manipulate both the aspects of interest and the aspects that threaten internal validity have been primarily used to make inferences about the average causal effect of the experimental manipulation. This article introduces a general framework for analyzing experimental data to make inferences about individual differences in causal effects. Approaches to analyzing the data produced by a number of classical designs and 2 more novel designs are discussed. Simulations highlight the strengths and weaknesses of the data produced by each design with respect to internal validity. Results indicate that, although the data produced by standard designs can be used to produce accurate estimates of average causal effects of experimental manipulations, more elaborate designs are often necessary for accurate inferences with respect to individual differences in causal effects. The methods described here can be diversely applied by researchers interested in determining the extent to which individuals respond differentially to an experimental manipulation or treatment and how differential responsiveness relates to individual participant characteristics. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Simple Model of Frequency-Dependent Impedance Functions in Soil-Structure Interaction Using Frequency-Independent Elements

This study presents a methodology to make a simple equivalent model of frequency-dependent impedance functions of soil-structure interactions using a frequency-independent spring and dashpot, together with a proposed element called “gyromass.” The gyromass is frequency independent and is defined as a unit system that generates a reaction force due to the relative acceleration of the nodes between which the gyromass is placed. It is found that a model consisting of a spring, dashpot, and gyromass may generate various types of frequency-dependent impedance characteristics. This study proposes two types of simple models that express typical frequency-independent impedance functions of soil-structure interactions by using the gyromass. The advantage of these models is that the frequency-dependent characteristics can easily be expressed by a small number of elements and degrees of freedom. Moreover, they can be applied directly to conventional time-history analyses, even beyond the elastic region of the structural members. An example in which a simple model is applied to the time-history analysis of a soil-pile-superstructure system with an inelastic structural member when subjected to an earthquake wave is illustrated.     

交流电弧炉三相不平衡供电的研究

提出了三相操作电抗随无量纲电流变化的三相交流电弧炉电路模型,进而给出了适用于三相电流不对称,电压不对称和阻抗不对称情况的计算模型。基于上述三相交流电弧炉电路模型,分析了电流不对称和阻抗不对称对电弧功率的影响,并讨论了交流电弧炉三相电参数互相影响的复杂性。依据本模型可灵活实现三相交流电弧炉的平衡和不平衡供电,进而改善电弧炉的电气运行特性。     

Multi-frequency static imaging in electrical impedance tomography: Part 1. Instrumentation requirements

Static images of the human body using electrical impedance tomography techniques can be obtained by measuring at two or more different frequencies. The frequencies used depend on the application, and their selection depends on the frequency behaviour of the impedance for the target tissue. An analysis using available data and theoretical models for tissue impedance yields the expected impedance and boundary voltage changes, therefore setting the measurement instrument specifications. The instrument errors produced by different sources are analysed, and, from this analysis it is possible to determine the feasibility of building the instrument, the limit values for some parameters (or components) and indications on the most suitable design of critical parts. This analysis also shows what kinds of error can be expected in the reconstructed images. It is concluded that it is possible to build an instrument with limited errors, allowing static images to be obtained. An instrument has been built that meets some of the design requirements and fails in others because of technological problems. In vivo images obtained with this instrument will be presented in Part 2 of this work.     

Caractéristiques perceptives et sémantiques dans la reconnaissance à court terme de mots. Une expérience avec des homonymes.

Several studies have shown that the recognition of homonyms can be affected if their meanings are changed by contextual manipulation. It does not necessarily follow that meaning is the sole determinant of recognition: Some studies show that the perceptual characteristics of words are more important for recognition than semantic properties. The present experiment with 8- and 16-yr-old students and young adults showed that, although context did induce changes in the encoding of homonyms, their recognition was not affected by these changes in meaning. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer among phonological manipulation skills.

Skills that require the manipulations of sounds that make up words are closely associated with the process of learning to read. This study involved an experimental analysis of the relations among phonological manipulation skills. Several skills were taught to 35 Head Start preschool children (mean age 5.2 yrs), and the degree to which learning 1 of these skills resulted in improved skill performance and accelerated learning of a 2nd skill was investigated. Instruction produced robust gains in skill performance and generalization of skills to novel instances. Posttest scores and data on students' efficiency of learning, however, offered no evidence of transfer across phonological manipulation skills. These results imply that the class of phonological manipulation skills does not have a simple structure and suggest that task and subject characteristics must be considered in predicting transfer among such skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bringing meaning to numbers: The impact of evaluative categories on decisions.

Decision makers are often quite poor at using numeric information in decisions. The results of 4 experiments demonstrate that a manipulation of evaluative meaning (i.e., the extent to which an attribute can be mapped onto a good/bad scale; this manipulation is accomplished through the addition of visual boundary lines and evaluative labels to a graphical format) has a robust influence in health judgments and choices and across diverse adult populations. The manipulation resulted in greater use of numeric quality-of-care information in judgments and less reliance on an irrelevant affective state among the less numerate. Recall results for provided quality-of-care numbers suggested that the manipulation did not influence depth of number processing with the exception of cost information that was not remembered as well. Results of a reaction-time paradigm revealed that feelings were more accessible than thoughts in the presence of the manipulation, suggesting that the effect may be due, at least in part, to an affective mechanism. Numeric information is often provided in decisions, but may not be usable by consumers without assistance from information providers. Implications for consumer decision making and the functions of affect are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dimensions of favorable self-presentation.

Conducted 2 studies to examine the importance of the tactic used in presenting a favorable self-image (denying negative characteristics vs attributing positive characteristics) and to examine the perceived audience of the self-presentation (internal vs external) on responses to self-report personality items. In Study 1, 60 items were administered under low or high conditions of identifiability to 244 undergraduates. None of the items were found to be sensitive to the identifiability manipulation, which suggested that none of these items could be identified as being particularly sensitive to external audience concerns. In Study 2 with 156 undergraduates, confirmatory factor analyses indicated that the process of attributing positive characteristics to the self is somewhat independent from the process of denying negative characteristics. Self-esteem was positively correlated with the tendency to unrealistically attribute positive traits to the self, and self-conscious persons were less likely to unrealistically deny negative characteristics. Findings suggest that the process of attributing positive characteristics to the self is different from the process of denying negative traits. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural Health Monitoring by Piezo-Impedance Transducers. I: Modeling

The electromechanical impedance (EMI) technique, which employs piezoelectric–ceramic lead–zirconate–titarate (PZT) patches as impedance transducers, has emerged as a powerful nondestructive evaluation technique during the last few years. This series of two papers present a new simplified methodology to diagnose structural damages by means of surface bonded piezo-impedance transducers. The first part introduces a new PZT–structure electroelastic interaction model based on the concept of “effective impedance.” The proposed formulations can be conveniently employed to extract the mechanical impedance of any “unknown” structural system from the admittance signatures of a surface bonded PZT patch. This is an improvement over the existing models, whose complexity prohibits direct application in similar practical scenarios. This also eliminates the requirement of any a priori information concerning the phenomenological nature of the structure. The proposed model is experimentally verified by means of test on a smart system comprising an aluminum block with a PZT patch instrumented on it. Part II of this paper outlines a new methodology to evaluate structural damages using the extracted impedance spectra. The proposed approach is found to be suitable for diagnosing damages in structures ranging from miniature precision machine and aerospace components to large civil structures.     

邻磺酰苯酰胺对镍电沉积过程电化学行为研究

利用交流阻抗法,研究了电沉积镍添加邻磺酰苯酰胺前后的交流阻抗图谱的变化趋势。通过Zsimp-Win软件对Nyquist图进行拟合,得到电沉积镍的等效电路图。判断邻磺酰苯酰胺在电沉积镍过程中的电化学机理,随着添加量的增加电荷传递电阻也随之增加,阴极极化增大。     

Some principles of sensory analysis.

Proposes 2 principles of sensory analysis concerning sensory discrimination and small, near-threshold stimuli that are incorporated into a simple model that is applied to the discrimination of differences in luminance. The phenomena surveyed include signal-detection operating characteristics, psychometric functions, and thresholds both for discriminations between 2 separate stimuli and for the detection of increments superimposed on a uniform luminance. The wide variety of phenomena that can be related to each of the 2 principles is discussed, including the Craik-Cornsweet Illusion, modulation transfer functions for sinusoidal gratings, negative masking, and the pedestal effect. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive processes and individual differences in judgments relevant to drunk driving.

The present study explored cognitive processes in judgments of drunkenness relative to legally allowable blood alcohol levels for driving. Judgments were based on the manipulation of three cues in hypothetical scenarios in a 3?×?4?×?3 factorial design (Type of Drink?×?Number of Drinks?×?Time to Consume). In addition, personality and behavioral characteristics influencing the accuracy of judgments of drunkenness relative to true blood alcohol levels were examined. Results indicated the presence of several misperceptions and inappropriate response tendencies that potentially can be modified with educational efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task effects on tactile temporal order judgments: When space does and does not matter.

The ability to report the temporal order of 2 tactile stimuli (1 applied to each hand) has been shown to decline when the arms are crossed over compared with when they are uncrossed. However, these effects have only been measured when temporal order was reported by stimulus location. It is unknown whether this spatial manipulation of the body affects all tactile temporal order judgments (TOJs) or only those judgments that are spatially defined. The authors examined the effect of crossing the arms on tactile TOJs when stimuli were identified by either spatial (location) or nonspatial (frequency or duration) attributes. Spatial TOJs were significantly impaired when the arms were in crossed compared with uncrossed postures, but there was no effect of posture when order was judged by nonspatial attributes. Task-dependent modulation of the effects of posture was also evident when response complexity was reduced to go/no-go responses. These results suggest that crossing the arms impairs tactile localization and thus spatial TOJs. However, the data also suggest that localization is not a necessary precursor when temporal order can be computed by nonspatial means. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tactics of manipulation.

Manipulation is one means by which environments are altered to correspond to characteristics of individuals. We conducted two studies to identify the manipulation tactics that people use to elicit and terminate the actions of others. Factor analyses of four instruments revealed six types of tactics: charm, silent treatment, coercion, reason, regression, and debasement. Tactics of manipulation showed strong individual difference consistency across contexts. The charm tactic, however, was used more frequently for behavioral elicitation, whereas the coercion and silent treatment tactics were used more frequently for behavioral termination. Manipulation tactics covaried significantly across self-based and observer-based data sources with personality scales of Neuroticism, Extraversion, Ambitious–Lazy, Arrogant–Unassuming, Quarrelsome–Agreeable, and Calculating and with characteristics of subjects' social environments. We draw implications for an interactionist framework of person–environment correspondence, for an expansion of the taxonomic task that faces personality psychology, and for identifying links between personality and other scientific disciplines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of motivations on the availability and retrieval of memory traces.

A review which analyzes a vast array of studies relating motivation and memory is presented. Investigations in which the motivational manipulation occurred during trace formation are distinguished from studies in which the manipulation occurred during trace storage or trace retrieval. Includes a series of investigations by the author which varied the incentive for retaining stimuli. The general conclusion is that many studies in the area are methodologically inadequate, and have yielded conflicting results. However, there are studies which provide strong evidence that memory can be influenced by nonassociative factors. (3 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vertebral hemangioma symptomatic during pregnancy. A case report and review of the literature

A simple four-tube arteries-microvessels-veins system which simulates a more realistic loading for human circulation was built using transmission line network. Hemodynamic data from literature are used in the fluid-circuit analogy, and the flow leakage and viscoelastic properties of the blood vessels have been considered. The effect of veins on the input impedance spectrum was found to be negligibly small above 0.5 Hz. The predicted input impedance spectra agree reasonably well with the published measurements both in shape and magnitude. Parametric analysis shows that the changes of vascular properties in the lower body affect the first minimum, and the changes in the upper body influence the second minimum. The blood flow in and out of kidney and liver dominates the aortic impedance from 0 to 5 Hz. Decreasing capacitance (i.e., increasing arterial stiffness due to aging), reducing the lumen area, or decreasing the length of blood vessels result in an increase in the impedance modulus, and the first minimum shift to a higher frequency which agree well with experiments. In the current model, the pressure, flow waveform, and local impedance can be predicted at any location along the circulatory tree. The characteristic of arterial pulse propagation resembles published measurements.     

Neural control of cochlear blood flow

Effects of intraarterial and intravenous injections of autonomic nervous system agents on cochlear blood flow were studied in order to investigate the neural control of the inner ear vessels. Blood flow changes in the inner ear of the guinea pig were measured with an electrical impedance plethysmograph. Rather weak control of the vertebrobasilar and labyrinthine arteries by the sympathetic nervous system of the alpha-receptor type did appear to exist. Beta-receptors of the sympathetic nerve appeared to be non-existent in the cochlear vessels, and parasympathetic modulation was not evident.     

Informational influence as a determinant of perceived task characteristics and job satisfaction.

Task characteristics and informational cues about the task were manipulated in a laboratory investigation of the impact of objective task design and informational influence in determining employees' perceptions of task characteristics and job satisfaction. Although a manipulation check involving 33 control Ss confirmed differences between the 2 experimental tasks (enriched and unenriched), results of the experiment with 42 graduate business students showed the major determinant of perceptions of task characteristics (Job Diagnostic Survey—JDS—and the Job Characteristic Inventory) and job satisfaction (JDS) to be informational influence in the form of cues about the task as either enriched or unenriched. Findings suggest that (a) job characteristics may be socially constructed as well as objective realities and that (b) perceptual measures of task dimensions may be susceptible to bias from informational cues. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

X80管线钢在西南地区土壤中的腐蚀电化学特征

采用电化学测试、SEM及EDS微观分析等方法,对X80管线钢在西南地区水饱和土壤中的腐蚀电化学特征进行了研究。结果表明,在水饱和西南土壤中,随腐蚀时间延长,X80钢腐蚀速率缓慢增大,腐蚀速度主要受氧扩散过程控制;EIS图谱具有双容抗弧与Warburg阻抗特征,电荷传递电阻和结合层电阻随时间而减小,腐蚀产物主要为铁的氧化...