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Curiosity—intrinsic motivation to understand—is an integral part of learning. However, empirical evidence on how and when students' curiosity is piqued is noticeably lacking, especially for boring learning materials. Grounded on the information gap theory, this study examined whether sequentially providing hints on the answer increased students' curiosity for interesting and boring trivia questions. Two experimental studies were conducted with 212 undergraduates. The number of hints was manipulated in the between- (Study 1; hint vs. no-hint) and within-individual (Study 2; 0 ~ 4 hints per question) levels. The results of both experiments showed that hints only incited curiosity when the content was boring. Providing hints also improved students' feeling-of-knowing the answer, performance (accuracy of guess), post-task interest, and willingness to reengage in the task. Encountering prediction errors (i.e., low-confidence correct guess or high-confidence error) triggered students' curiosity about the explanation. These findings contribute to the growing body of curiosity literature and help educators make mundane learning content curious. [ABSTRACT FROM AUTHOR]

We demonstrate a two-step hybrid process for fabricating movable parts inside glass substrate using the selective laser-induced etching (SLE) process that is consisted of laser-direct writing and wet chemical etching. To obtain an influence by the optical characteristics of a glass substrate when fabricating a 3D microstructure using the SLE, we analyzed the relationship of their dimensions between the designed and the fabricated devices. Two 3D microfluidic devices are designed and fabricated on glass substrates as the demonstrations of the hybrid process: a 3D microfluidic valve device with a movable plug and a 3D microfluidic mixer with a rotatable impeller and multilayer microchannels. The valving plug and the impeller of each device are successfully moved and rotated. The smallest structure is a pillar of the impeller device, and its size is 29 μm (diameter) × 277 μm (height). We expect this study to be extended to potential applications in 3D glass microfabrication and microfluidic systems. [ABSTRACT FROM AUTHOR]

This review aims to clarify four perennial issues surrounding the concept of curiosity: its nature, conceptual distinction from situational interest, types, and educational implications. First, we argue that humans have evolved to be deeply curious to adapt to a world of uncertainty. Curiosity can be likened to an appetite for knowledge which can be satiated by specific information that fills a knowledge gap. Information-seeking behavior is determined by the expected availability of information using a cost–benefit analysis. Second, although curiosity and situational interest are often considered synonyms, we show that the two constructs differ in terms of their theoretical account, biological underpinnings, triggering factors, emotional valence, specificity of information searches, and relationship with individual interest. Unlike situational interest, which is the positive affect triggered by a wide variety of sources (e.g., autonomy, relatedness, competence), curiosity is an aversive cognitive state caused by an information gap. Situational interest follows the hedonic principle and is associated with opioid liking system in the brain. Curiosity, by contrast, is understood through drive theory and involves dopaminergic wanting system. Situational interest drives individuals to approach the stimulus while curiosity promotes the active seeking of missing information. Iterative cycles of curiosity resolution can lead to the development of individual interest. Third, we introduce two types of curiosity: curiosity for what (forward curiosity) is provoked by unpredictability, whereas curiosity for why (backward curiosity) arises from incongruity. Finally, driven by the unique characteristics of curiosity, we suggest ways to design learning environment that can nurture students' curiosity. [ABSTRACT FROM AUTHOR]

Users using social networking service (SNS) may express their thoughts and feelings using simple hashtags. Hashtags are related to other hashtags and images that are used together in the user's other posts. Understanding the meaning of personal hashtags can be a way to learn latent semantic expressions of personal words. Existing methods for learning and analyzing semantics such as Latent Semantic Analysis, Latent Dirichlet Allocation and Word Embedding need large-scale corpus to construct an elaborate model. Large-scale corpus usually consists of words that a lot of people already use. Thus, existing methods are able to catch the latent meaning of words used in general. However, it is difficult for these methods to find personal meanings of words that are used by a particular person. Because the number of words that a person use is usually very small compared to a large-scale corpus. Another reason for the difficulty is that existing methods use occurrence frequency or co-occurrence probability. Therefore, the importance or the frequency or the probability of personalized meaning may disappear because of this large difference in the number of words. In this research we focused on the classification of semantic words using a user's hashtag data and the co-occurrence of these hashtags. The performance is evaluated and enhances previous work by 18% for Precision and more than 70% for Recall. [ABSTRACT FROM AUTHOR]

The static and dynamic displacements of high-speed railway bridges, which are determined by the load conditions, travel speed, and span, may cause passenger discomfort when they are excessive. In the Korea Railway Bridge Design Specifications, the allowable deflection is based on the train travel speed. It is, however, not sufficient for considering the vibration serviceability. The Eurocodes has also been quoted in the design guidelines of the Korean Honam High-speed Railway (KRNA, 2007). For the determination of the vibration serviceability of a passenger train, the Eurocodes proposes a deflection limit based on the vibration serviceability obtained from the ratio of the deflection to the span and considers the bridge-train interaction. However, the maximum speed and maximum span in the Eurocodes are 350 km/h and 120 m, respectively. Moreover, it does not provide a detailed process for determining the deflection limit based on vibration serviceability. It is therefore difficult to use the deflection limit as the design limit in increasing the span and travel speed. Hence, to ensure passenger comfort and enable changes in railway techniques, it is necessary to develop a vibration serviceability-based deflection limit that flexibly responds to changes in the railway environment regarding bridge span and travel speed. This study was conducted to determine the deflection limits of Korean railway bridges based on their vibration serviceability and considering the bridge-train interaction and increase in travel speed. In this paper, the bridge-train transfer function is developed using a simplified bridge-train model comprising a single mass-spring system. It is then verified by dynamic analysis of the bridge-train interaction. A parametric study and bridge-train dynamic interaction analysis are used to determine the correlation between the vertical acceleration of a car body and the bridge displacement with increasing travel speed. In addition, the vertical acceleration of the car body is shown to increase with increasing travel speed, and an amplification coefficient of the vertical acceleration of the car body is suggested. Further, a vibration serviceability deflection limit for high-speed railway bridges is developed in this paper using the transfer function and the amplification coefficient. Here, the deflection and vibration of the bridge are assumed to be respectively sinusoidal and harmonic. The suggested vibration serviceability deflection limit is also compared with those in the Eurocodes and the Shinkansen. [ABSTRACT FROM AUTHOR]

Efficient design of device-to-device (D2D) communication calls for D2D users to propose adaptive power allocation strategy and to establish reliable communication links while protecting the QoS of cellular communications. In this paper, we consider the D2D communication as an underlay to relay-assisted cellular networks. To maximize the ergodic capacity, we derive an optimal transmission power under an average power constraint. With the derived optimal transmission power, a transmission period selection strategy for D2D communication is firstly introduced to improve reliability. We derive the outage probability in closed forms and evaluate the ergodic capacity to show performances of the proposed system. Numerical results show that the D2D system can achieve high capacity gains by flexibly allocating transmission power based on channel state information and significantly enhance reliability by selecting a transmission period, while satisfying various QoS conditions for cellular communication. [ABSTRACT FROM AUTHOR]

This study was performed to investigate the effects of IL-32 on joint inflammation, bone destruction, and synovial cytokine expressions, and on synovial natural killer (NK) cell expressions in collagen-induced arthritis (CIA). CIA was induced by type II collagen in DBA1 mice, and phosphate-buffered saline (PBS group) or IL-32 (IL-32 group) were injected into both knee joints at day 28 and 32, then mice were killed at day 35. Severity of synovial inflammation and bone destruction was determined by histological scoring method, and synovial cytokine expressions such as IL-1β, TNF-α, IL-17, IL-18, IFN-γ, IL-21, and IL-23 were measured by real-time RT-PCR and western blot. Synovial NK cell expressions were determined by real-time RT-PCR, western blot and immunohistochemistry, and chemokines and chemokine receptors expressions that are associated with NK cell migration were determined by real-time RT-PCR. Scores of synovial inflammation and bone destruction, synovial expressions of IL-1β, TNF-α, IL-18, and IFN-γ were significantly increased in IL-32 group compared with PBS group. Synovial expressions of NK cell, and chemokines (CCL2 and CXCL9) and chemokine receptors (CCR2 and CCR5) that are associated with NK cell migration were significantly increased in IL-32 group compared with PBS group. IL-32 aggravated joint inflammation and bone destruction and increased synovial expressions of inflammatory cytokine and NK cells in CIA. These results suggest that IL-32 play a role in joint inflammation and bone destruction, and IL-32 might be a new target for treatment of rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

In this paper, a decode-and-forward cooperative interference-limited multiple relay network is considered. An efficient relay selection strategy and its performance analysis are proposed, where only the relay nodes are affected by multiple interferences. In the proposed relay selection scheme, the selected relay is not always used, depending on the power of interferences and the channel state information of all links, while the direct path between source and destination is always used. For analytical tractability the distribution of interference-limited channel is approximated as an exponential distribution with high accuracy. Analysis of cooperative networks with interference-limited relays can be performed using the approximate exponential distribution by the same methods which have been used without interferences. We derive the bit error probability and outage probability of the proposed opportunistic max-min relay selection (OMRS) scheme in independent non-identically distributed Rayleigh fading channels. Numerical results present the superiority of OMRS over the conventional relay selection scheme which always uses the selected relay path. The exactness of the approximate analysis for interference-limited relays is also shown in numerical results. [ABSTRACT FROM AUTHOR]

We explored the neural correlates of bridging inferences and coherence processing during story comprehension using Positron Emission Tomography (PET). Ten healthy right-handed volunteers were visually presented three types of stories (Strong Coherence, Weak Coherence, and Control) consisted of three sentences. The causal connectedness among sentences in the Strong Coherence story was strong that readers would not have to generate bridging inferences, whereas the causal antecedent of the last sentence in the Weak Coherence story was not explicitly stated so that readers should draw bridging inferences to fill the gap between sentences. It was found that the left middle temporal gyrus was activated while participants read the Weak Coherence stories. In contrast, the dorsomedial prefrontal cortex (dmPFC) and posterior cingulate cortex were activated only in the Strong Coherence condition. This suggests that the dmPFC was involved in coherence processing whereas bridging inference was mediated by the left middle temporal gyrus. It was also found that anterior temporal pole and the temporo-parietal junction mediated general semantic processing. [ABSTRACT FROM AUTHOR]

Recently, newly developed bake-hardenable (BH) steel sheets strengthened by copper sulfide (CuS) have been successfully employed in commercial production lines that supply automotive outer panels. The metallurgical concepts governing fabrication of these new BH steel sheets require keeping carbon content as low as 0.0015 wt.% without any additional amount of titanium and/or niobium for solute carbon scavenging. The role of CuS precipitates has turned out to raise the yield strength acting as a barrier against dislocation movement. In this paper, we studied the effects of chemical compositions and manufacturing process variables on the microstructure and mechanical properties of newly developed BH steel sheets. We found that the control of carbon and nitrogen showed a good balance between bake-hardenability (BH) and yield point elongation (YP-El). We identified the crystallographic relationship between the nano-size CuS precipitates and the ferrite matrix of (001)//(001) and [001]//[001]. We also found that the BH and YP-El were affected by the formation of aluminium nitride (AlN) and the annealing temperature. [ABSTRACT FROM AUTHOR]

Unossified horn or pilose antler cut from deer, which belong to the Cervidae generally is termed Nokyong. Nokyong is one of the most famous Korean traditional medicines and has been considered to possess sexual-reinforcing and antiaging actions. In this study, water extract of deer antler extract (DAA) prepared from the growing antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe was used to investigate the efficacy of the DAA on the development of type II collagen (CII)-induced arthritis (CIA) in rats. Male rats were immunized with an emulsion of 200 μg of CII and complete Freund's adjuvant (CFA). The rats then were administered by injection a suspension of DAA or phosphate-buffered saline. The effect of DAA on cellular responses to CII was examined. The injection of DAA suppressed the CII-specific secretion of interferon (IFN)-ψ from splenocytes ex vivo. The influence of DAA also was evaluated on the incidence and developmen0105 of arthritis in rat CIA. Rats were immunized twice at a 3-wk interval with bovine CII, with DAA being given by injection once a d for 14 d with four different regimens. A 14-d course of DAA treatment at a daily dose of 100 μg/kg, which began on the d of the first CII immunization, suppressed the development of arthritis, as well as antibody formation and delayed-type hypersensitivity to CII. Treatment with DAA resulted in inhibition of development of arthritis and immune responses to CII. [ABSTRACT FROM AUTHOR]

The high-temperature deformation behavior and dynamic softening transition from dynamic recrystallization (DRX) to dynamic recovery (DRV) of Al-18 wt.%Si alloy was studied by torsion tests in a temperature range of 573∼773 K and a strain rate range of 0.001∼1/sec. The alloy was produced by spray-forming followed by hot extrusion. The dependence of flow stress (σ) on strain rate $$(\dot \varepsilon )$$ and temperature (T) could be described by the power Arrhenius relationship, $$\dot \varepsilon = A \sigma _p^n exp( - Q/RT)$$ . The activation energy and stress exponent values were higher at the low temperature region than those at the high temperature region. The alloy showed a flow curve of DRX in the temperature range of 573∼673 K, while at 673∼773 K, the alloy exhibited a flow curve of DRV. These results were analyzed by observing the shapes of the flow curves throughout the deformation condition. Also, the transition behavior from DRX to DRV has been investigated through observation of deformed microstructure and flow curves during hot deformation. [ABSTRACT FROM AUTHOR]

The high-temperature deformation behavior of AISI 430 ferritic stainless steel was studied by torsion tests. The deformation tests were performed in the temperature range of 900–1100°C and strain rate range of 5.0×10−2 −5.0/sec. The evolutions of flow stress and microstructure show the characteristics of continuous dynamic recrystallization (CDRX). The flow stress gradually decreased with strain over the peak stress without steady state. Below the 100% effective strain, grains appeared in small angle grain boundaries with a misorientation of 3–9°. In addition, when heavy deformation (>300%) was applied, higher misorientation (∼15°) was achieved. The tendency of CDRX increased with increasing strain rate and decreasing temperature. The dependence of CDRX grain size on the strain rate and temperature was discussed. [ABSTRACT FROM AUTHOR]

To develop an effective protocol of gene transfer into glomeruli, an ex vivo gene delivery system using rat mesangial cells (RMC) as a vector was examined. RMC genetically engineered with a retrovirus harboring the Escherichia coli beta-galactosidase gene was used to estimate the efficacy of gene delivery and the location of the cells within the kidney. The RMC expressing beta-galactosidase, RMCLZ1, was cultured in vitro and the cells were injected into the left kidney through the renal artery of a normal Sprague Dawley rat. At least I x 10[sup 6] RMCLZ1 was required for effective gene delivery into glomeruli. One hour and 1, 4, and 14 d after injection, glomeruli were isolated from the left kidneys injected with the cells and the expression of beta-galactosidase in each glomeruli was evaluated. One hour and 1 d after injection, more than 90 and 80%, respectively, of glomeruli from the left kidney showed strong beta-galactosidase activity, while no activity of beta-galactosidase was found in the glomeruli from the right kidneys. The number of glomeruli stained by X-gal and the intensity decreased with time. Fourteen days after injection, about 35% of the glomeruli retained the RMCLZ1. X-gal and periodic acid-Schiff staining of frozen sections obtained 14 d after injection allowed the estimation of the site where the mesangial cells injected were located. The mesangial cells were found mainly in two different locations, the glomerular capillary and the mesangium. The majority (about 90%) of the mesangial cells were located in the glomerular capillary and about 9% of the cells were in the mesangial area. Occasionally, the positive staining was found in proximal tubules and the interlobular artery. Although additional methods are required for the site-specific targeting of the mesangial area, the ex vivo gene transfer to glomeruli is feasible and... [ABSTRACT FROM AUTHOR]

To establish the overexpression and one-step purification system of Bacillus subtilis elongation factor-Tu (EF-Tu), the EF-Tu gene was amplified with or without own ribosome binding site (rbs) by PCR and the only PCR product without rbs was subcloned successfully. For the expression of the EF-Tu gene cloned after PCR amplification, a constitutive expression system and inducible expression system with His[sub 6] tag at N-terminus or C-terminus, or glutathione-S-transferase (GST) fusion system were examined in E. coli and B. subtilis. Except GST fusion system in E. coli, however, all other trials were unsuccessful at the step of plasmid construction for the EF-Tu expression. The GST/EF-Tu fusion proteins were highly expressed by IPTG induction and obtained as both soluble and insoluble form. From the soluble GST/EF-Tu fusion protein, EF-Tu was obtained to near homogeneity by one-step purification with glutathione-sepharose affinity column chromatography followed by factor Xa treatment. The purified EF-Tu showed high GDP binding activity. These results indicate that the GST/ EF-Tu fusion system is favorable to overexpression and purification of B. subtilis EF-Tu. [ABSTRACT FROM AUTHOR]

Previous research investigating the encoding, encoding-plus-storage, and extermal-storage functions of note taking has failed to equate processing opportunities among the groups. The present studies did so by having the encoding group take notes on two occasions without review, the encoding-plus-storage group take notes one time and review notes the next, and the external-storage group twice review a set of borrowed notes. Three forms of note taking were used: conventional, and note taking on skeletal and matrix frameworks. In both Experiment 1, involving lecture learning, and Experiment 2, involving text learning, an advantage was found for the encoding-plus-storage function on tests involving factual-recall and recognition performance but not on tests measuring higher-order performance. With respect to note-taking forms, no advantage existed for any form when information was acquired from lecture. When text material was used there was some advantage for conventional notes and a clear advantage for not taking notes at all, but instead twice reading the material. These findings were explained relative to observed note-taking behaviors, the opportunity for review, and the processing demands proposed by the combination of reading and note taking, particularly when notes must be classified into an existing framework. [ABSTRACT FROM AUTHOR]

The torsion tests of 304 stainless steel were performed in the temperature range of 900~1100°C and strain rate range of 5.0 × 10-2~5.0 × 10°/sec to study the high temperature softening behavior. The flow curves and microstructures showed the behavior of dynamic recrystallization (DRX). The dependence of temperature(T) and the stain rate(ɛ) on the flow stress was expressed by the hyperbolic sine law, ɛ=2.75 × 10 (sinh 0.076σ)5.26 exp(-379000 J/mol/RT). The dynamically recrystallized grain size(dDRX) was related to the value of the Zener-Hollomon parameter Z. Under the Z value of 1017, it was found that the grain size ranged from 10 to 20 μm. The relationship between the dynamically recrystallized grain size and Z parameter was found as follows: dDRX=l 39.48-7.33 log Z and the calculated grain sizes were well matched with the experimental values. To determine the optimum condition of plastic deformation, the deformation map was made from the efficiency of power dissipation. The maximum efficiency was 0.41 at the condition of 1100°C, 0.5/sec, 100%. [ABSTRACT FROM AUTHOR]

The origin of unconventional superconductivity and its relationship to a T = 0 K quantum critical point (QCP), which is hidden inside the dome of a superconducting state, have long been an outstanding puzzle in strongly correlated superconductors. The observation and tuning of the hidden QCP, which is key to resolving the mystery, however, has been rarely reported. Here we report the controlling of a hidden QCP in the helical antiferromagnet CrAs and separation of the tuned QCP from the pressure-induced superconducting phase. The Al doping in CrAs increases the antiferromagnetic ordering temperature TN from 265 to 275 K, while it suppresses the QCP from 8 to 4.5 kbar. Pressure-induced superconductivity in the high-pressure regime is almost independent of Al doping, but superconductivity below 6 kbar is suppressed, revealing the clear separation between the tuned antiferromagnetic QCP and Tc maximum. These discoveries illustrate subtleties in the interplay between superconductivity and quantum criticality and warrant a deeper insight in understanding of unconventional superconductivity. [ABSTRACT FROM AUTHOR]

The recent observation of extremely large magnetoresistance (MR) in the transition-metal dichalcogenide MoTe2 has attracted considerable interest due to its potential technological applications as well as its relationship with novel electronic states predicted for a candidate type-II Weyl semimetal. In order to understand the origin of the MR, the electronic structure of MoTe2−x (x = 0.08) is systematically tuned by application of pressure and probed via its Hall and longitudinal conductivities. With increasing pressure, a monoclinic-to-orthorhombic (1 T′ to Td) structural phase transition temperature (T*) gradually decreases from 210 K at 1 bar to 58 K at 1.1 GPa, and there is no anomaly associated with the phase transition at 1.4 GPa, indicating that a T = 0 K quantum phase transition occurs at a critical pressure (Pc) between 1.1 and 1.4 GPa. The large MR observed at 1 bar is suppressed with increasing pressure and is almost saturated at 100% for P > Pc. The dependence on magnetic field of the Hall and longitudinal conductivities of MoTe2−x shows that a pair of electron and hole bands are important in the low-pressure Td phase, while another pair of electron and hole bands are additionally required in the high-pressure 1 T′ phase. The MR peaks at a characteristic hole-to-electron concentration ratio (nc) and is sharply suppressed when the ratio deviates from nc within the Td phase. These results establish the comprehensive temperature-pressure phase diagram of MoTe2−x and underscore that its MR originates from balanced electron-hole carrier concentrations. [ABSTRACT FROM AUTHOR]

The recent observation of extremely large magnetoresistance (MR) in the transition-metal dichalcogenide MoTe2 has attracted considerable interest due to its potential technological applications as well as its relationship with novel electronic states predicted for a candidate type-II Weyl semimetal. In order to understand the origin of the MR, the electronic structure of MoTe2−x (x = 0.08) is systematically tuned by application of pressure and probed via its Hall and longitudinal conductivities. With increasing pressure, a monoclinic-to-orthorhombic (1 T′ to Td) structural phase transition temperature (T*) gradually decreases from 210 K at 1 bar to 58 K at 1.1 GPa, and there is no anomaly associated with the phase transition at 1.4 GPa, indicating that a T = 0 K quantum phase transition occurs at a critical pressure (Pc) between 1.1 and 1.4 GPa. The large MR observed at 1 bar is suppressed with increasing pressure and is almost saturated at 100% for P > Pc. The dependence on magnetic field of the Hall and longitudinal conductivities of MoTe2−x shows that a pair of electron and hole bands are important in the low-pressure Td phase, while another pair of electron and hole bands are additionally required in the high-pressure 1 T′ phase. The MR peaks at a characteristic hole-to-electron concentration ratio (nc) and is sharply suppressed when the ratio deviates from nc within the Td phase. These results establish the comprehensive temperature-pressure phase diagram of MoTe2−x and underscore that its MR originates from balanced electron-hole carrier concentrations. [ABSTRACT FROM AUTHOR]