Neutral Background Research Articles

The Memory Bias Toward Negative Context in Episodic Memory in Anxiety Individuals—An Exploratory Study Through ERPs

In order to explore the memory bias toward negative context in anxiety individuals, this study explored the cognitive neural mechanisms of at different cognitive process amongst 30 college students (high and low anxiety groups of 15 people each) by using event-related potentials (ERPs) measurement and source memory multiple-task paradigm. At first, it was found that the ERPs of fearful was stronger than the neutral background in the condition of hit <sub>item w/ source </sub>(both the old item and the source were judged correctly), hit item<sub> w/o source</sub> (the old item was judged correctly and the source was not judged correctly) and latter forgotten (both the old item and the source were not judged correctly) generally in the encoding phase. Combined with the behavior data, reaction times of hit item <sub>w/o source</sub> in fearful context were fasten than neutral context. Secondly, as for the memory bias, ERPs were more positive in fear context than neutral context at Fcz/Cz/Cpz in the 700-900ms in the high anxiety group under the condition of hit <sub>item w/o source</sub>. In addition, ERPs were more positive in fear context than neutral context in the 300-500ms under the condition of latter forgotten in the high anxiety group. In conclusion, the memory bias towards negative stimuli in anxiety individuals was found in the encoding phase, indicating that anxiety still had an impact in the early stages of processing, but not in the deep processing.

The effects of shared, depression-specific, and anxiety-specific internalizing symptoms on negative and neutral episodic memories following post-learning sleep.

Emotional memory bias is a common characteristic of internalizing symptomatology and is enhanced during sleep. The current study employs bifactor S-1 modeling to disentangle depression-specific anhedonia, anxiety-specific anxious arousal, and the common internalizing factor, general distress, and test whether these internalizing symptoms interact with sleep to influence memory for emotional and neutral information. Healthy adults (N = 281) encoded scenes featuring either negative objects (e.g., a vicious looking snake) or neutral objects (e.g., a chipmunk) placed on neutral backgrounds (e.g., an outdoor scene). After a 12-hour period of daytime wakefulness (n = 140) or nocturnal sleep (n = 141), participants judged whether objects and backgrounds were the same, similar, or new compared with what they viewed during encoding. Participants also completed the mini version of the Mood and Anxiety Symptom Questionnaire. Higher anxious arousal predicted worse memory across all stimuli features, but only after a day spent being awake-not following a night of sleep. No significant effects were found for general distress and anhedonia in either the sleep or wake condition. In this study, internalizing symptoms were not associated with enhanced emotional memory. Instead, memory performance specifically in individuals with higher anxious arousal was impaired overall, regardless of emotional valence, but this was only the case when the retention interval spanned wakefulness (i.e., not when it spanned sleep). This suggests that sleep may confer a protective effect on general memory impairments associated with anxiety.

Heating mode transitions in capacitively coupled CF4 plasmas at low pressure

Abstract Capacitively coupled plasmas operated in CF4 at low pressure are frequently used for dielectric plasma etching. For such applications the generation of different ion and neutral radical species by energy dependent electron impact ionization and dissociation of the neutral background gas is important. These processes are largely determined by the space and time dependent electron energy distribution function and, thus, by the electron power absorption dynamics. In this work and based on a particle-in-cell/Monte Carlo collision model, we show that the electron heating mode in such plasmas is sensitive to changes of the gap at a constant pressure of 3 Pa. At a gap of 1.5 cm, the dominant mode is found to be a hybrid combination of the Drift-Ambipolar (DA) and the α-mode. As the gap is increased to 2 cm and 2.5 cm, the bulk power absorption and ambipolar power absorption decreases, and the DA mode decays. When the gap reaches 3 cm, the α-mode becomes more prominent, and at a gap of 3.75 cm the α-mode is dominant. These mode transitions are caused by a change of the electronegativity and are found to affect the discharge characteristics. The presence of the DA-mode leads to significant positive electron power absorption inside the bulk region and negative power absorption within the sheaths on time average, as electrons are accelerated from the bulk towards the collapsed sheath. The heating mode transitions result in a change from negative to positive total electron power absorption within the sheaths as the gap increases. When accounting for secondary electron emission, the transition of the heating mode can occur at shorter gaps due to the enhanced plasma density and decreased electronegativity.

How different backgrounds in video interviews can bias evaluations of applicants

AbstractOrganizations are increasingly using technology‐enabled formats such as asynchronous video interviews (AVIs) to evaluate candidates. However, the personal environment of applicants visible in AVI recordings may introduce additional bias in the evaluation of interview performance. This study extends existing research by examining the influence of cues signaling affiliation with Islam or homosexuality in the background and comparing them with a neutral background using an experimental design and a German sample (N = 222). Results showed that visible signs of religious affiliation with Islam led to lower perceived competence, while perceived warmth and interview performance were unaffected. Visual cues of homosexuality had no effect on perceptions of the applicant. In addition, personal characteristics of the raters, such as their intrinsic religious orientation or their attitudes towards homosexuality influenced applicants’ ratings, so that a non‐Muslim religious orientation was negatively associated with evaluations of the Muslim candidate and a negative attitude towards homosexuality was negatively associated with evaluations of the homosexual candidate. This study thus contributes to the literature on AVIs and discrimination against Muslims and members of the 2SLGBTQI+ community in personnel selection contexts.

Targeted Memory Reactivation during Nonrapid Eye Movement Sleep Enhances Neutral, But Not Negative, Components of Memory.

Emotionally salient components of memory are preferentially remembered at the expense of accompanying neutral information. This emotional memory trade-off is enhanced over time, and possibly sleep, through a process of memory consolidation. Sleep is believed to benefit memory through a process of reactivation during nonrapid eye movement sleep (NREM). Here, targeted memory reactivation (TMR) was used to manipulate the reactivation of negative and neutral memories during NREM sleep. Thirty-one male and female participants encoded composite scenes containing either a negative or neutral object superimposed on an always neutral background. During NREM sleep, sounds associated with the scene object were replayed, and memory for object and background components was tested the following morning. We found that TMR during NREM sleep improved memory for neutral, but not negative scene objects. This effect was associated with sleep spindle activity, with a larger spindle response following TMR cues predicting TMR effectiveness for neutral items only. These findings therefore do not suggest a role of NREM memory reactivation in enhancing the emotional memory trade-off across a 12 h period but do align with growing evidence of spindle-mediated memory reactivation in service of neutral declarative memory.

Risk and low-density dispersed urbanism

Settlements operate across a wide range of densities and do so for every socio- economic mode of life from those based on hunter-gatherer economies to those which are based on industrial production. Human beings also live across a range of residential densities from very high to very low. Why they do so is a function of many factors, especially differing socio-cultural ways of managing interaction and communication and the associated social and political practices of the communities. Settlement forms are seen as a derivative of many factors because they are. But they are not thereby an epiphenomenon - especially as they become larger, more durable, and bulkier. That gives them inertia and, as a consequence, they become an agency in their own right which produces outcomes with consequences for the communities, which inhabit them. They are not a neutral background. Instead, their materiality, their sizes, and their densities have an impact on the viability of social life. This paper considers the outcomes generated by the regional networks of low-density, urban settlements larger than 100 sq km in extent. The implications of what happened to agrarian-based low-density urban settlements, like Greater Angkor and the Classic Maya settlements, such as Caracol, are of consequence for the risk faced by the regional networks of present-day, low-density urban giants – the megalopoleis and desa-kota. A further perspective is provided by placing these great cities of the past and the present in the larger context of the trajectories and outcomes of smaller low-density settlements over the previous six millennia. The concern is the implications for the viability of low-density urbanism in contexts of the rapid, extreme climate change we are now beginning to experience. The implications are ominous, yet the past also indicates that social and cultural systems are robust, that human beings can survive, and that they retain and continue to remake their social traditions as they adjust to seriously changing circumstances.

Optimally localized single-band Wannier functions for two-dimensional Chern insulators

The construction of optimally localized Wannier functions (and Wannier functions in general) for a Chern insulator has been considered to be impossible owing to the fact that the second moment of such functions is generally infinite. In this article, we propose a solution to this problem in the case of a single band isolated from the rest of the band structure. We accomplish this by drawing an analogy between the minimization of the variance and the minimization of the electrostatic energy of a periodic array of point charges in a smooth neutralizing background. In doing so, we obtain a natural regularization of the diverging variance and this leads to an analytical solution to the minimization problem. We demonstrate our results numerically for a particular model system. Furthermore, we show how the optimally localized Wannier functions provide a natural way of evaluating the electric polarization for a Chern insulator. Published by the American Physical Society 2024

Anhedonia reflects an encoding deficit for pleasant stimuli in schizophrenia: Evidence from the emotion-induced memory trade-off eye-tracking paradigm.

The present study explored the hypothesis that anhedonia reflects an emotional memory impairment for pleasant stimuli, rather than diminished hedonic capacity in individuals with schizophrenia (SZ). Participants included 30 SZ and 30 healthy controls (HCs) subjects who completed an eye-tracking emotion-induced memory trade-off task where contextually relevant pleasant, unpleasant, or neutral items were inserted into the foreground of neutral background scenes. Passive viewing and poststimulus elaboration blocks were administered to assess differential encoding mechanisms, and immediate and 1-week recognition testing phases were completed to assess the effects of delay interval. Participants also made self-reports of positive emotion, negative emotion, and arousal in response to the stimuli. Results indicated that SZ experienced stimuli similarly to HC. Both groups demonstrated the typical emotion-induced memory trade-off during the passive viewing and poststimulus elaboration encoding blocks, as indicated by more hits for emotional than neutral items and fewer hits for backgrounds paired with emotional than neutral items. Eye-tracking data also indicated that both groups were more likely to fixate earlier and have longer dwell time on emotional than neutral items. At the 1-week delay, the emotion-induced memory trade-off was eliminated in both groups, and SZ showed fewer overall hits across valence conditions. Greater severity of anhedonia was specifically associated with impaired recognition for pleasant stimuli at the immediate recognition phase. Findings suggest that anhedonia in SZ is associated with emotional memory impairment, particularly a deficit in encoding positive stimuli. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Electron–ion temperature relaxation in nonideal plasmas: High accuracy classical molecular dynamics simulations

AbstractIn this work, we prepare a simulation framework for a high‐accuracy numerical study of electron–ion temperature relaxation in nonideal (strongly coupled) plasmas. The existing relaxation rate theories require either parameter selection or some pre‐knowledge of the electron–ion correlation functions and effective interaction potentials. This makes non‐equilibrium classical and quantum molecular dynamics simulations a crucial stage in the study of energy transfer rates. We begin by revisiting the classical molecular dynamics simulations of a system of equally charged particles with different masses on a neutralizing background. We accurately simulate this simple ab‐initio (parameterless) system with controlled precision in terms of number of particles, mass ratio, and energy convergence. The predictions for the equally charged system are compared to the previous simulations and theories, which are reproduced with higher accuracy. We also perform a series of classical molecular dynamics simulations of the system of oppositely charged particles with the corrected Kelbg potential based on the quantum statistical approach. We analyze the differences and similarities between the same‐charge and opposite‐charge systems. Some remarks about the forthcoming application of quantum simulations with the help of WPMD or WPMD‐DFT methods are given.

Age-related positivity effect in emotional memory consolidation from middle age to late adulthood.

While younger adults are more likely to attend to, process, and remember negative relative to positive information, healthy older adults show the opposite pattern. The current study evaluates when, exactly, this positivity shift begins, and how it influences memory performance for positive, negative, and neutral information. A total of 274 healthy early middle-aged (35-47), late middle-aged (48-59), and older adults (>59) viewed scenes consisting of a negative, positive, or a neutral object placed on a plausible neutral background, and rated each scene for its valence and arousal. After 12 h spanning a night of sleep (n = 137) or a day of wakefulness (n = 137), participants completed an unexpected memory test during which they were shown objects and backgrounds separately and indicated whether the scene component was the "same," "similar," or "new" to what they viewed during the study session. We found that both late middle-aged and older adults rated positive and neutral scenes more positively compared to early middle-aged adults. However, only older adults showed better memory for positive objects relative to negative objects, and a greater positive memory trade-off magnitude (i.e., remembering positive objects at the cost of their associated neutral backgrounds) than negative memory trade-off magnitude (i.e., remembering negative objects at the cost of their associated neutral backgrounds). Our findings suggest that while the positivity bias may not emerge in memory until older adulthood, a shift toward positivity in terms of processing may begin in middle age.

The metameric effect of monolithic zirconias with varying yttrium ratios.

To evaluate the metameric disparities among monolithic zirconia materials with differing yttrium compositions across various lighting conditions. Thirty-six square-shaped zirconia samples measuring 10 × 10 × 0.5 mm were prepared from monolithic zirconia materials with three different yttrium contents. A 0.2 mm thick layer of polymerized dual-polymerizable self-adhesive resin cement was created using a silicone mold with the same dimensions as the prepared zirconia specimens. To evaluate metamerism, color measurements were conducted using a spectrophotometer device on a neutral gray background in a color measurement cabinet that offers four different illumination environments. All samples underwent aging by subjecting them to 10000 thermal cycles using a thermal cycle tester. Following thermal aging, color measurements were taken once more, and the data were recorded using the CIE L*, a*, b* color system. Two-way ANOVA and Post-hoc Bonferroni tests were employed to analyze the data. It was observed that there was no statistical difference among the color measurements made in different illumination environments of the monolithic zirconia ceramics used to evaluate metamerism (P > .05). This observation remained consistent both before and after thermal aging. After thermal aging, the color of monolithic zirconia materials exhibited a tendency towards red and yellow hues, accompanied by a decrease in brightness levels. It can be stated that different illumination conditions did not affect the metamerism of monolithic zirconia materials, but there was a color change in monolithic zirconia materials after a thermal aging period equivalent to one year.

Eye tracking evidence for the reinstatement of emotionally negative and neutral memories.

Recent eye tracking studies have linked gaze reinstatement-when eye movements from encoding are reinstated during retrieval-with memory performance. In this study, we investigated whether gaze reinstatement is influenced by the affective salience of information stored in memory, using an adaptation of the emotion-induced memory trade-off paradigm. Participants learned word-scene pairs, where scenes were composed of negative or neutral objects located on the left or right side of neutral backgrounds. This allowed us to measure gaze reinstatement during scene memory tests based on whether people looked at the side of the screen where the object had been located. Across two experiments, we behaviorally replicated the emotion-induced memory trade-off effect, in that negative object memory was better than neutral object memory at the expense of background memory. Furthermore, we found evidence that gaze reinstatement was related to recognition memory for the object and background scene components. This effect was generally comparable for negative and neutral memories, although the effects of valence varied somewhat between the two experiments. Together, these findings suggest that gaze reinstatement occurs independently of the processes contributing to the emotion-induced memory trade-off effect.

Interaction Potential between a Uniformly Charged Square Nanoplate and Coplanar Nanowire

We study a structure consisting of two electrostatically interacting objects, a uniformly charged square nanoplate and a uniformly charged nanowire. A straightforward motivation behind this work is to introduce a model that allows a classical description of a finite two-dimensional quantum Hall system of few electrons when the Landau gauge is imposed. In this scenario, the uniformly charged square nanoplate would stand for the neutralizing background of the system while a uniformly charged nanowire would represent the resulting quantum striped state of the electrons. A second important feature of this model is that it also applies to hybrid charged nanoplate-nanowire systems in which the dominant interaction has electrostatic origin. An exact analytical expression for the electrostatic interaction potential between the uniformly charged square nanoplate and coplanar nanowire is obtained by using a special mathematical method adept for this geometry. It is found that the resulting interaction potential is finite, monotonic and slowly-varying for all locations of the nanowire inside the nanoplate.

Context effects on the perception of saturation of fruit colors in still-life paintings.

Still-life painters, especially of the so-called Golden Age (17th century) in the Netherlands, are famous for their masterful techniques of rendering reality. Their amazing abilities to depict different material properties of fruits and flowers are stunning. But how important are these careful arrangements of different objects for the perception of an individual item? Is the perceived color saturation of a single fruit influenced by its surrounding context? We selected fruits in still-life paintings as stimuli to investigate whether and how perceived saturations of fruits were affected by their original contexts. In our study, we focused especially on effects of five context properties: complementary colors, chromatic and luminance contrast, object overlap, and surround variance. Six fruit varieties depicted in high-quality digital reproductions of 48 classic and eight varieties in 64 more recent, modern still-life paintings were selected. In a single trial, eight images of fruits of the same variety appeared on a neutral gray background; half were single fruit cutouts, and the other half were the same fruits embedded in their circular contexts. Fifteen participants ranked all eight images according to perceived color saturations of the fruits. Saturation ratings showed a high agreement of 77%. Surrounding contexts led to an increase in perceived saturation of central fruits. This effect was mainly driven by object overlap, the presence of the central fruit type also in the context, and surround variance. Chroma contrast between fruits and contexts decreased saturation significantly. No significant context effects were found for complementary colors or luminance contrast. Our results show that in paintings, many of the cues that are usually experimentally isolated occur in interesting combinations and lead to an increase in perceived saturation that makes fruit objects more appealing and convincing.

Hybrid data-driven and mechanism-modeling approaches for online injection rate sensing of dual-fuel co-direct injector under carbon neutral background

This study proposes an innovative concept for online sensing of the injection process. By using the injector inlet as the pressure signal detection point, contactless testing of the injector is achieved, theoretically requiring no structural changes to commercial engines or standard injectors. For the pilot diesel injection, the pressure signal is abstracted as the evolution and transmission of Riemann waves, and the relationship between pressure and mass flow rate is established. Additionally, correction and decoupling methods for system interference and superimposed waves are proposed to extract Riemann single-wave components caused by injection. For the main fuel gas injection process, a data-driven injection mass neural network prediction model is constructed based on the pressure drop characteristic, which achieves quantitative sensing of the injection characteristics. Moreover, concerning gas pressure fluctuation, the interference phenomenon in the first-order differential pressure signal is identified. It is found that gas pressure waves propagate as second-order micro-pressure in the HPDI system, and the columns of pressure waves do not interfere with each other. A qualitative reconstruction method for the injection rate curve is developed based on 1D mechanistic models. In conclusion, this study uses hybrid data-driven and mechanism-modeling approaches to achieve online sensing. By comparing with offline testing methods, it exhibits high accuracy, with errors in the majority of injection parameters remaining within 5.5%.

The monopole and quadrupole moments of the epoch of reionization (EoR) 21-cm bispectrum

ABSTRACT We study the monopole ($\bar{B}^0_0$) and quadrupole ($\bar{B}^0_2$) moments of the 21-cm bispectrum (BS) from EoR simulations and present results for squeezed and stretched triangles. Both $\bar{B}^0_0$ and $\bar{B}^0_2$ are positive at the early stage of EoR where the mean neutral hydrogen (${\rm H\, {\small I}}$) density fraction $\bar{x}_{\rm {\rm H\, {\small I}}}\approx 0.99$. The subsequent evolution of $\bar{B}^0_0$ and $\bar{B}^0_2$ at large and intermediate scales (k = 0.29 and $0.56 \, {\rm Mpc}^{-1}$, respectively) is punctuated by two sign changes which mark transitions in the ${\rm H\, {\small I}}$ distribution. The first sign flip where $\bar{B}^0_0$ becomes negative occurs in the intermediate stages of EoR $(\bar{x}_{\rm {\rm H\, {\small I}}}\gt 0.5)$, at large scale first followed by the intermediate scale. This marks the emergence of distinct ionized bubbles in the neutral background. $\bar{B}^0_2$ is relatively less affected by this transition, and it mostly remains positive even when $\bar{B}^0_0$ becomes negative. The second sign flip, which affects both $\bar{B}^0_0$ and $\bar{B}^0_2$, occurs at the late stage of EoR $(\bar{x}_{\rm {\rm H\, {\small I}}}\lt 0.5)$. This marks a transition in the topology of the ${\rm H\, {\small I}}$ distribution, after which we have distinct ${\rm H\, {\small I}}$ islands in an ionized background. This causes $\bar{B}^0_0$ to become positive. The negative $\bar{B}^0_2$ is a definite indication that the ${\rm H\, {\small I}}$ islands survive only in underdense regions.

New Insights into the Coloration Mechanism in Spessartines and the Impact of Munsell Neutral Grey Backgrounds

In this study about spessartines,13 spessartine samples with proper conditions are used for FTIR spectrum and UV-Vis spectrum tests to find the gemological characteristics and coloration mechanism. In the UV-Vis spectrum, spessartines’ special color has a relationship with the absorption bands at about 460 nm and 480 nm. Based on the CIE 1976 L*a*b* colour system, we come to the conclusion that both color coordinates a* and b* control the value of chroma C*, and color coordinate b* mostly controls the hue angle h°. We also explore how the different chromogenic ions FeOtot and MnO and their ratio FeOtot/MnO influence spessartines’ color, finding that the color of spessartine samples is influenced by both Mn and Fe. By analyzing the FTIR spectrum, we discovered that as the content of Mn decreases, and the A, C and D peaks move to the position of a longer wave, the color of spessartine samples also changes significantly. By using the standard light source D65, we find that N9.5 Neutral Grey Background is the best background to grade the color of spessartines.

Experimental and simulation study on the backstreaming positive ions on the quarter-size negative ion source for CRAFT NNBI test facility

As an effective methods of plasma heating, neutral beam injection (NBI) systems based on negative hydrogen ion sources will be utilized in future magnetic-confinement nuclear fusion experiments. Because of the collisions between the fast negative ions and the neutral background gas, the positive ions are inevitable created in the acceleration region in the negative NBI system. These positive ions are accelerated back into the ion source and become high energy backstreaming ions. In order to explore the characters of backstreaming ions, the track and power deposition of backstreaming H+ beam is estimated using the experimental and simulation methods at NNBI test facility. Results show that the flux of backstreaming positive ions is 1.93 % of that of negative ion extraction from ion source, and the magnet filed in the beam source has an effect on the backstreaming positive ions propagation.

Behind the scenes: Impact of virtual backgrounds in educational videos on visual processing and learning outcomes.

The increasing use of instructional videos in educational settings has emphasized the need for a deeper understanding of their design requirements. This study investigates the impact of virtual backgrounds in educational videos on students' visual information processing and learning outcomes. Participants aged 14-17 (N=47) were randomly assigned to one of three conditions: a video with a neutral, authentic, or off-topic background. Their prior knowledge and working memory capacity (WMC) were measured before watching the video, and eye tracking data was collected during the viewing. Learning outcomes and student experiences were assessed after viewing. The eye tracking data revealed that a neutral background was the least distracting, allowing students to pay better attention to relevant parts of the video. Students found the off-topic background most distracting, but the negative effect on learning outcomes was not statistically significant. In contrast to expectations, no positive effect was observed for the authentic background. Furthermore, WMC had a significant impact on visual information processing and learning outcomes. These findings suggest that educators should consider using neutral backgrounds in educational videos, particularly for learners with lower WMC. Consequently, this research underscores the significance of careful design considerations in the creation of instructional videos.

Molecular Dynamics-Based Modeling of Ion-Neutral Collisions in an Open Ion Trajectory Simulation Framework.

Ion mobility spectrometry (IMS) and ion mobility mass spectrometry (IMS-MS) methods have become increasingly popular and are important analytical techniques to determine information about the structural parameters of gas-phase analytes. The accurate description of the interaction between molecular ions and neutral background gas particles is an essential part of high-quality simulations of such modern mass- and ion-mobility-spectrometric systems. Established ion-neutral collision models (Hard-sphere collision modeling and statistical diffusion simulations) in common ion-trajectory simulation systems like SIMION use strongly simplified assumptions and are thus limited in their predictive ability. In contrast, collision cross-section (CCS) modeling programs (e.g., MOBCAL, IMoS, and Colloidoscope) allow high-quality ion mobility predictions for low-field equilibrium conditions using explicit scattering processes with a molecular dynamics-based trajectory method but cannot be used for nonequilibrium collision modeling in an ion trajectory simulation. This work presents an extension to the open-source Ion Dynamics Simulation Framework (IDSimF), which allows the simulation of ion dynamics under arbitrary and even nonequilibrium conditions. It was extended by an advanced collision model employing the molecular dynamics trajectory method for a detailed microscopic description of ion-neutral collisions within ion-trajectory simulations. We used drift tube ion mobility spectrometry (DT-IMS) to validate the predictive abilities of the model and to estimate the runtime requirements for productive simulations. Simulated high-field ion mobilities for small ion systems in a drift tube IMS are compared to experimental values from the literature and an implementation of a hard-sphere model in IDSimF for helium and argon as background gas particles. Significant improvements in ion mobility predictions using the molecular dynamics trajectory approach are obtained with deviations of only a few percent from experimental values. Therefore, the established and publicly available MD collision model will serve as foundation for nonequilibrium ion dynamics simulations and the development of improved ion dynamics modeling methods.