Measuring the exchange-stiffness constant of nanocrystalline solids by elastic small-angle neutron scattering

In ferromagnets with a non-uniform magnetocrystalline and/or magnetoelastic anisotropy, such as nanocrystalline or cold-worked polycrystalline materials, the static magnetic microstructure gives rise to elastic magnetic small-angle neutron scattering (SANS). The paper explores a method for determining the exchange-stiffness constant A by analysis of the dependence of the elastic SANS cross-section on the applied magnetic field. Experimental results for A and for the spin-wave stiffness constant D in cold-worked or nanocrystalline Ni and Co are found to agree with literature data obtained by inelastic neutron scattering on single-crystal specimens.     

Regularized ELM bagging model for Tropical Cyclone Tracks prediction in South China Sea

This paper aims to improve the prediction accuracy of Tropical Cyclone Tracks (TCTs) over the South China Sea (SCS) with 24 h lead time. The model proposed in this paper is a regularized extreme learning machine (ELM) ensemble using bagging. The method which turns the original problem into quadratic programming (QP) problem is proposed in this paper to solve lasso and elastic net problem in ELM. The forecast error of TCTs data set is the distance between real position and forecast position. Compared with the stepwise regression method widely used in TCTs, 8.26 km accuracy improvement is obtained by our model based on the dataset with 70/1680 testing/training records. By contrast, the improvement using this model is 16.49 km based on a smaller dataset with 30/720 testing/training records. Results show that the regularized ELM bagging has a general better generalization capacity on TCTs data set.     

Infant imitation from television using novel touch screen technology

Infants learn less from a televised demonstration than from a live demonstration, the video deficit effect. The present study employs a novel approach, using touch screen technology to examine 15‐month olds' transfer of learning. Infants were randomly assigned either to within‐dimension (2D/2D or 3D/3D) or cross‐dimension (3D/2D or 2D/3D) conditions. For the within‐dimension conditions, an experimenter demonstrated an action by pushing a virtual button on a 2D screen or a real button on a 3D object. Infants were then given the opportunity to imitate using the same screen or object. For the 3D/2D condition, an experimenter demonstrated the action on the 3D object, and infants were given the opportunity to reproduce the action on a 2D touch screen (and vice versa for the 2D/3D condition). Infants produced significantly fewer target actions in the cross‐dimension conditions than in the within‐dimension conditions. These findings have important implications for infants' understanding and learning from 2D images and for their using 2D media as the basis of actions in the real world.     

Evaluation of the interaction between D1 and D2 receptors in a drug discrimination paradigm

Recent research has suggested that there is a synergistic interaction between D1 and D2 dopamine (DA) receptors and that D1 stimulation by endogenous DA is necessary for the expression of some D2-mediated behavioral effects. The purpose of the present experiment was to examine further the interactions between D1 and D2 receptors using drug discrimination (DD), a behavioral paradigm that is sensitive and selective for D1 and D2 agonist and antagonist activity. Two groups of male Sprague-Dawley rats (N = 8/group) were trained to discriminate the D2 agonist quinpirole (QUIN; either 0.05 or 0.012 mg/kg, ip, 10 min pre-session) from saline (1.0 ml/kg, ip, 10 min pre-session) in a two-lever, food-reinforced DD paradigm. QUIN (0.0015-0.1 mg/kg) produced a dose-related increase in QUIN-appropriate responding in both groups of rats. The D1 agonist SKF 38393 (SKF; 6.4-12.8 mg/kg, ip) given alone did not substitute for QUIN in either of the two training dose groups. The administration of SKF 30 min before QUIN had no effect on the QUIN dose-response function in either group of rats. These results indicate that stimulation of D1 receptors failed to potentiate a behavioral effect mediated by D2 receptors. The D1 antagonist SCH 23390 (SCH; 0.0015-0.05 mg/kg, ip) partially substituted for QUIN in the group trained with the 0.05 dose of QUIN, and to a larger extent in the group trained with the 0.012 dose of QUIN. SCH did not alter the effect of the training dose of QUIN except at a dose high enough to virtually eliminate lever pressing in the group trained to discriminate the high dose of QUIN. The failure of SCH to block QUIN suggests that D1 receptor stimulation by endogenous DA is not necessary for this D2 effect to be expressed. These results may be accounted for by assuming a presynaptic site of action for QUIN in the QUIN discrimination. Further, they demonstrate that the interaction between D1 and D2 receptors cannot be simply characterized as synergistic.     

Elastic and phonon properties of quaternary Heusler alloys CoFeCrZ (Z = Al,Si, Ga and Ge) from density functional theory

The structural, elastic and phonon properties of the quaternary CoFeCrZ (Z = Al, Si, Ga and Ge) Heusler alloys have been investigated using the generalized gradient approximation method within density functional theory. The ground-state properties, including, lattice constant and bulk modulus are in good agreement with the available theoretical and experimental data. The elastic constants C_ij are computed using the stress–strain technique. The calculated results indicate that CoFeCrZ (Z = Al, Si, Ga and Ge) alloys are ductile materials. Debye temperatures are predicted from calculated elastic constants. The phonon dispersion relations of CoFeCrZ (Z = Al, Si, Ga and Ge) alloys are calculated for the first time using the density functional theory and the direct method with 2 × 2 × 2 supercell.     

Detection of stimulus change: The hypothetical roles of visual transient responses

Two random-dot patterns (D1 and D2) were displayed briefly in close temporal succession, separated by an interstimulus interval (ISI). The two patterns were identical except that D2 could contain one more element (addition) or one less element (subtraction) than D1. Observers were required to detect the addition or subtraction using a two-alternative forced-choice method. Three experiments were designed to examine Phillips and Singer’s (1974) suggestion that detection of additions and subtractions can be explained in terms of neural ON and OFF responses. Experiment 1 replicated Phillips and Singer’s finding that performance is progressively impaired as the ISI is increased. In Experiment 2, sudden shifts in luminance between D1 and D2 were combined with several durations of ISI to produce transient responses in a novel manner. Experiment 3 explored the roles of transient neural responses and of configurational changes as determinants of performance. Most predictions based on Phillips and Singer’s model were confirmed by the experimental outcomes. Some discrepancies between theory and data are noted, and directions for further research are suggested.     

Roles of dopamine D1 and D2 receptors in the acquisition and expression of fat-conditioned flavor preferences in rats

Sugars and fats elicit innate and learned flavor preferences with the latter mediated by flavor-flavor (orosensory) and flavor-nutrient (post-ingestive) processes. Systemic dopamine (DA) D1 (SCH23390: SCH) and D2 (raclopride: RAC), but not opioid antagonists blocked the acquisition and expression of flavor-flavor preferences conditioned by sugars. In addition, systemic D1, but not D2 or opioid antagonists blocked the acquisition of flavor-nutrient preferences conditioned by intragastric (IG) sugar infusions. Given that DA antagonists reduce fat intake, the present study examined whether systemic D1 or D2 antagonists altered the acquisition and/or expression of conditioned flavor preferences (CFP) produced by pairing one novel flavor (CS+, e.g., cherry) with a 3.5% corn oil (CO: fat) solution relative to another flavor (CS-, e.g., grape) paired with a 0.9% CO solution. In an expression study, food-restricted rats were trained to drink either flavored 3.5% or 0.9% CO solutions on alternate days. Subsequent two-bottle tests with the CS+ and CS- flavors mixed in 0.9% CO solutions occurred 0.5h after systemic administration of vehicle (VEH), SCH (50-800 nmol/kg) or RAC (50-800 nmol/kg). The rats displayed a robust CS+ preference following VEH treatment (87-88%) the expression of which was attenuated by treatment with moderate doses of RAC, and to a lesser degree, SCH. In an acquisition study, six groups of rats received VEH, SCH (25, 50, 200 nmol/kg) or RAC (50, 200 nmol/kg) 0.5 h prior to 1-bottle training trials with CS+ flavored 3.5% and CS- flavored 0.9% (CS-) CO solutions. A seventh Limited VEH group was trained with its training intakes limited to that of the SCH and RAC groups. Subsequent two-bottle tests were conducted with the CS+ and CS- flavors presented in 0.9% CO without injections. Significant and persistent CS+ preferences were observed in VEH (75-82%), Limited VEH (70-88%), SCH25 (75-84%), SCH50 (64-87%), SCH200 (78-91%) and RAC200 (74-91%) groups. In contrast, the group trained with RAC50 displayed a significant initial CS+ preference (76%) which declined over testing to 61%. These data indicate limited DA D1 and D2 receptor signaling involvement in the expression and acquisition of a fat-CFP relative to previous robust effects for sugar-CFP.     

Density-functional and shell-model calculations of the energetics of basal-plane stacking faults in sapphire

We report the generation of fullerenes and nanotubes using an arc discharge on graphite in a high-pressure nozzle. The vapour from the arc is quenched via collisions with helium gas, forming carbon clusters within a localized highpressure region. The carbon molecules are entrained in the gas jet as it expands into the vacuum and deposited onto a silicon substrate in a low-pressure (6 mT) environment. Mass spectroscopy measurements of the plasma reveal the presence of C molecules in the expanding plume. Microstructural examination of films deposited using this method revealed clustered regions of larger fullerenes and nanotubes surrounded by an amorphous matrix. Films containing fullerenes and nanotubes were found to be significantly harder and more elastic than amorphous carbon films deposited under identical parameters but without conditions for fullerene and/or nanotube formation.     

Le cycle journée/nuit : étude du développement des connaissances chez l’enfant français et comparaison de méthodes

The aim of this work is to study the knowledge development process about night and day cycle during ontogeny, by comparing two diverging theoretical and methodological approaches, on 178 elementary school children (6-7 years old, 8-9 years old and 10-11 years old). We hypothesis that the dimension (2D/3D) of the representation, the question type (open versus forced choice) and the age of the student have an effect on the amount of correct answers and on the coherence between the answers. The results show that the knowledge acquisition process regarding night and day cycle follows a gradual path during ontogeny and that the method used has a significant effect on the number of correct answers given by the children. Indeed, heliocentric model is given minority when children are asked with open questions (only 31% of the children). On the contrary 76% of them choose the heliocentric perspective when asked with forced-choice questions. The support's dimension (2D/3D) has no effect.     

Lack of correlation between digit ratio (2D:4D) and Baron-Cohen’s “Reading the Mind in the Eyes” test, empathy, systemising, and autism-spectrum quotients in a general population sample

The second-to-fourth digit ratio (2D:4D) is sexually differentiated and is a likely biomarker for the organisational (permanent) effects of prenatal testosterone on the human brain. Recent research has highlighted a possible role of prenatal testosterone levels in both the etiology of autism-spectrum disorders and in sex and individual differences in cognitive styles of the normal mind (Baron-Cohen’s Extreme Male Brain Theory of Autism and Empathising/Systemising Theory). Importantly, autistic children present lower (hypermasculinised) 2D:4D than healthy controls. Based on these accounts, we investigated the relation of 2D:4D with Baron-Cohen’s measures of empathising (“Reading the Mind in the Eyes” test, RMET; Empathy Quotient, EQ), systemising (Systemising Quotient, SQ), and autistic-like traits (Autism-Spectrum Quotient, AQ) in the general population (N = 423 Austrian adults). Whereas sex differences into the expected direction and of expected size were obtained for all variables and internal scale consistencies tallied to retrievable reference values, 2D:4D was unrelated to RMET, EQ, SQ, and AQ scores. Candidate explanations for this lack of correlation might be possible developmental timing differences in the expression of 2D:4D and empathising/systemising, qualitative (as opposed to quantitative) functional differences between the normal and the autistic mind, or the suboptimal psychometric properties of the measures.     

The priority of just-identified,recursive models

Theories often place constraints on causal relationships, and such constraints are often assessed with causal models. Causal models should be recursive and just identified because cause is recursive and is more likely to be just identified than overidentified. A just-identified, recursive model (JIRM) is specified that satisfies both requirements and that can be used to assess a wide range of causal implications in either a norm-referenced or criterion-referenced manner. P. E. Meehl and N. G. Waller (2002) proposed an innovative method for theory appraisal called the delete one-add one (D1-A1) method, which assesses a relatively narrow range of causal implications, allows nonrecursive models, and is only norm referenced. The JIRM and D1-A1 methods are compared.     

Visual knowledge discovery and machine learning for investment strategy

Knowledge discovery is an important aspect of human cognition. The advantage of the visual approach is in opportunity to substitute some complex cognitive tasks by easier perceptual tasks. However for cognitive tasks such as financial investment decision making this opportunity faces the challenge that financial data are abstract multidimensional and multivariate, i.e., outside of traditional visual perception in 2D or 3D world. This paper presents an approach to find an investment strategy based on pattern discovery in multidimensional space of specifically prepared time series. Visualization based on the lossless Collocated Paired Coordinates (CPC) plays an important role in this approach for building the criteria in the multidimensional space for finding an efficient investment strategy. Criteria generated with the CPC approach allow reducing/compressing space using simple directed graphs with beginnings and the ends located in different time points. The dedicated subspaces constructed for time series include characteristics such as Bollinger Band, difference between moving averages, changes in volume etc. Extensive simulation studies have been performed in learning/testing context. Effective relations were found for one-hour EURUSD pair for recent and historical data. Also the method has been explored for one-day EURUSD time series n 2D and 3D visualization spaces. The main positive result is finding the effective split of a normalized 3D space on 4 × 4 × 4 cubes in the visualization space that leads to a profitable investment decision (long, short position or nothing). The strategy is ready for implementation in algotrading mode.     

An explanation of the indentation size effect in ceramics

Abstract

A quantitative model is proposed to explain the indentation size effect (ISE) often observed in the hardness response of hard brittle materials, namely that hardness is observed to increase with decreasing indentation size. The model is based on a mixed elastic/plastic materials deformation response whereby plastic deformation occurs in a discrete manner progressively to relieve stresses created by elastic flexure of the surface at the edges of the indentation. During unloading of the indenter, recovery of the elastic increment of deformation, which precedes each new band of plastic deformation, results in the indentation appearing smaller than expected, particularly as the indentation sizes decrease to approach the scale of the plastic deformation band spacing. The model fits observed experimental data well and analysis of hardness/size data in this way is shown to allow both a bulk hardness value and a characteristic deformation band scale to be calculated for a given sample.     

Strain-dependent effects of post-training dopamine receptor agonists and antagonists on memory storage in mice.

Post-training administration of the selective D1 or D2 agonists SKF 38393 and LY 171555 dose dependently impairs retention of an inhibitory avoidance response in DBA/2 mice. In agreement, the selective D1 or D2 antagonists SCH 23390 and (-)-sulpiride improve retention. These effects are opposite to those observed in the C57BL/6 strain, as previously reported. Moreover, B6D2F1 hybrids present a response to SKF 38393, LY 171555, SCH 23390, and (-)-sulpiride that parallels that of the C57BL/6 strain, thus suggesting that the neural mechanisms underlying the effects of DA agonists or antagonists on memory processes may be inherited through a dominant mode of inheritance.     

Dimensional Sensitivity of the 15D Multiattribute Utility Instrument in Diabetic Retinopathy

The purpose of this study was to further investigate the previously suggested high sensitivity of the 15D instrument to diabetic retinopathy (DR) by examining: i) its dimensional sensitivity in patients differing in DR severity, and ii) its dimensional relationship with a well-known vision-targeted health status instrument. Eighty five diabetes patients with non-proliferative or proliferative DR completed the 15D and the National Eye Institute Visual Function Questionnaire 25-item (NEI-VFQ-25) instruments. Dimensional response distributions were examined with chi-square, and mean VFQ25 and 15D dimension score differences with ANCOVA. Dimensional relationships between the instruments were assessed with correlations and ordinary least squares (OLS) regressions. Patients with proliferative DR scored significantly lower (P?<?0.05 or better) on 9/15 and 10/12 of the 15D and VFQ25 dimensions respectively. Correlations were mostly strong (>0.50) and significant (P?<?0.001). Most OLS models with 15D dimensions as predictors of VFQ25 subscales showed high explanatory power (adjusted R ²?>?0.85 in 10/13 models), with ocular pain being the only exception (R ²?=?0.44). The 15D’s seeing dimension was a significant predictor of 10 VFQ25 scales, whereas speech was not significant in any model. 15D utilities discriminated between the DR subsamples, supporting its appropriateness in this group. Its dimensions (seeing in particular), explained large portions of variance in NEI-VFQ25 scales, implying a strong association with this vision-targeted instrument. These findings might help to explain why 15D performs well in DR and support its use for QALY calculations. However, the need remains for further testing in larger and more diverse samples.     

词素效应到底是什么？——来自维吾尔语的证据

利用维吾尔语的一些特点,采用视觉－视觉启动、听觉－视觉跨通道启动、和延迟重复启动等三种启动技术,改变目标词和启动词之间在词素、词形以及语义上的多种关系,通过比较启动效应的异同,来考察词素效应是否可以还原为词形启动效应、语义效应,是否可以看成是词形和语义在实时加工中相互作用的后果,从而探讨词汇加工中词素效应的实质。实验一发现,在明确配对的视觉－视觉和跨通道启动中,启动词和目标词之间只有在具有词素加语义关系（＋m＋o＋s / D,＋m＋o＋s / R;其中,m 代表词素,o 代表词形,s 代表语义,D 代表目标词为派生词,R代表目标词为自由词根;＋ 表示启动词和目标词之间在某个维度上相关,－表示启动词和目标词之间在某个维度上无关）时或者仅仅具有语义关系（－m－o＋s / D）时,才有显著的启动效应。如果启动词与目标词之间仅仅具有词素（词形）关系,而没有语义关系（＋m＋o－s / D）,或者仅仅具有词形关系（－m＋o－s / R）,它们之间的启动效应微乎其微。实验二通过使用维吾尔语中的借词和延迟启动技术,比较了词素加语义加词形（＋m＋o＋s / D）的启动和语义加词形启动（－m＋o＋s / D）以及语义启动（－m＋o＋s / D）,发现词素启动效应并没有不同于其他启动条件下的效应。两个实验都表明,语义关系是产生启动效应的关键,没有语义相关,就不可能产生词素启动,词素效应依赖于语义效应。有了语义关系,词素关系和词形关系产生的作用很小。因此,词汇加工的词素效应是词形和语义统计学规律的反应,是词形和语义加工相互作用的后果,心理词典中并不需要明确地表征词汇结构。     

Strain-dependent interactions between MK-801 and cocaine on retention of C57BL/6 and DBA/2 mice tested in a one-trial inhibitory avoidance task: involvement of dopaminergic mechanisms

Two sets of experiments were carried out with C57BL/6 (C57) and DBA/2 (DBA) mice tested in a one-trial inhibitory avoidance task. In the first set C57 and DBA mice were injected posttraining with saline or with the D1 DA receptor antagonist SCH 23390 and then with saline, cocaine (5 mg/kg), MK-801 (0.1 mg/kg), or with a combination of these two drugs. Cocaine enhanced retention in the C57 strain and impaired it in the DBA strain, and MK-801 potentiated the effects of cocaine in both strains. Furthermore, pretreatment with SCH 23390 completely antagonized the potentiation of the effects of cocaine exerted by MK-801. In the second set of experiments mice belonging to these same two strains were injected posttraining with vehicle or with the D2 DA receptor antagonist (-)-sulpiride and then with saline, cocaine (5 mg/kg), MK-801 (0.1 mg/kg), or with a combination of these two drugs. Pretreatment with the D2 DA receptor antagonist completely antagonized in both strains the potentiation of the effect of cocaine exerted by MK-801. The results of the present research show that the noncompetitive NMDA receptor antagonist MK-801 enhances the effect of cocaine on retention performance in C57 and DBA mice and that dopaminergic mechanisms are involved in this potentiation.     

Possible participation of D3 and D4 dopaminergic receptors on genital reflexes induced by cocaine in paradoxical sleep deprived male rats

Previous studies have demonstrated that paradoxical sleep deprivation (PSD) potentiates cocaine-induced genital reflexes in male rats and both D1 and D2 receptors may play a role in those effects, and to examine the possibility that such might involve other dopaminergic receptors, we investigated the effects of D3 and D4 receptor subtype antagonists on cocaine-induced reflexes in sleep-deprived rats. Separate groups of PSD rats received saline, D3 (U9919A; 0.75, 1.5 and 3 mg/kg) or D4 (L745870; 0.75, 1.5 and 3 mg/kg) antagonists prior to acute cocaine challenge. Results demonstrated that U9919A induced significant reduction in the number of animals that displayed erection and the frequency of erection at two smaller doses, while no significant difference was reported for the D4 receptor antagonist. Although our studies indicate that there is a relevant participation of D3 receptors in male sexual function, D4 receptors seem not to exert an essential role in this model.     

A powerful,inexpensive experiment controller or IBM PC interface and experiment control language

A very powerful, but inexpensive, advanced technology (16 MHz 80C188EB) experiment controller is described. It can be programmed in either a BASIC-like (ECBASIC) or an ALGOL-like (ECL) procedure specification language. It provides 1-msec resolution, optional transparent total data logging, and is designed to function as a remote peripheral processor in a network with virtually any computer acting as the network supervisor (e.g., IBM compatible or Macintosh). Each serial port on the host computer can support up to 10 simultaneous experiments. The various optional I/O modules provide for opto-isolated normally open or normally closed switch operation input, high current output, as well as D/A and A/D functions. Our I/O modules can also be plugged directly into an IBM PC parallel port by using a small adaptor board. In this way, the advantages of using ECBASIC or ECL to control experiments are available to researchers who wish to simply interface their host computer directly to the apparatus in order to minimize expense.