Variance In Size Research Articles

Weed detection in sesame fields using a YOLO model with an enhanced attention mechanism and feature fusion

Weeds have a significant impact on sesame throughout its early stages of development, thus they must be rigorously controlled. However, the shape of sesame seedlings and weeds are similar, and the size specifications are not defined, making reliable weed detection difficult. To achieve the goal of weed recognition, the majority of solutions now use a deep learning model to learn the weed image. Weed targets with big variances in size and specification are easy to overlook with the current deep learning algorithm. As a result, standard deep learning models have room for improvement when it comes to sesame and weed recognition rates. The YOLO-sesame model is proposed to improve the efficiency and accuracy of sesame weed identification. Based on the YOLOv4 model, an attention mechanism is introduced. Local importance pooling is added to the SPP layer, on which the SE module is used as a logical module. To address the issue of large differences in target size and specifications, an adaptive spatial feature fusion structure is included at the feature fusion level. The experimental results suggest that the YOLO-sesame model proposed in this study outperforms mainstream models such as Fast R-CNN, SSD, YOLOv3, YOLOv4, and YOLOv4-tiny in terms of detection performance. Sesame crops and weeds received F1 scores of 0.91 and 0.92, respectively, while the mAP was 96.16%. The detecting frame rate was 36.8 per second. In conclusion, the YOLO-sesame model successfully meets the needs for accurate sesame weed detection.

Assessing cumulative impacts of human-induced pressures on reef and sandbank habitats and associated biotopes in the northeastern Baltic Sea.

Marine ecosystems are impacted by multiple individual and combined anthropogenic pressures. We used meta-analysis and data-driven PlanWise4Blue decision support tool to predict individual and combined impacts of wind park development, nutrient loading, and invasive species on vulnerable reef and sandbank habitats and associated species-specific biotopes in the northeastern Baltic Sea. Many impacts were not statistically significant due to large between-study variance in effect sizes. Wind park development is predicted to have less impact than nutrient loading and invasive species. Predicted impacts varied greatly among larger-scale habitats versus smaller-scale biotopes with impacts being generally stronger at small scale. Excessive nutrient loading damages algae-based biotopes, the presence of nonnative species has substantial negative impacts on larger-scale reef and sandbank habitats. The results showed that a 25 % reduction of nutrient loading improves all examined benthic habitats, whereas nonnative species, which cannot be removed from ecosystems, pose a significant threat to these habitats.

Intercomparison of nanodosimetric distributions in nitrogen simulated with Geant4 and PTra track structure codes

To facilitate the use of Geant4-DNA for radiation transport simulations in micro- and nanodosimeters, which are physically operated with tissue-equivalent gases such as nitrogen (and propane), this work aims to extend the cross section data available in Geant4-DNA to include those of nitrogen for electron energies ranging from 1 MeV down to the ionisation threshold. To achieve this, interaction cross section data for nitrogen that have been used with the in-house PTB PTra track structure code have been implemented in the current state-of-the-art Geant4-DNA simulation toolkit. An intercomparison has been performed between the two codes to validate this implementation. To quantify the agreement between the cross section models for nitrogen adopted in PTra and those implemented in Geant4-DNA, the simulation results of both codes were analysed using three physical parameters describing the ionisation cluster size distribution (ICSD): mean ionisation cluster size, variance of the cluster size and the probability to obtain a single ionisation within the target. Statistical analysis of the results indicates that the interaction cross section models for nitrogen used in PTra (elastic scattering, impact ionisations and electronic excitations) have been successfully implemented in Geant4-DNA. In addition, simulated ICSDs were compared to those measured with the Jet Counter nanodosimeter for energies between 100 and 2000 eV. For greater energies, the ICRP data for LET and particle range were used as a reference. The modified Geant4-DNA code and data successfully passed all these benchmarks fulfilling the requirement for their public release in the next version of the Geant4 toolkit.

Growth and Welfare of African Catfish (Clarias gariepinus Burchell, 1822) under Dietary Supplementation with Mixed-Layer Clay Mineral Montmorillonite-Illite/Muscovite in Commercial Aquaculture

Juvenile African catfish (Clarias gariepinus Burchell, 1822) were reared within two experiments (a research facility and a local catfish farm, E1 and E2, respectively) for 102 d each under commercial recirculating aquaculture conditions. The mixed-layer clay mineral montmorillonite–illite/muscovite (1g557) was applied as a feed additive at concentrations of 0.5% and 2.0%, which were compared with an unsupplemented control (0.0%) over 70 d. For E1, feeding was automatic at night, while E2 was fed manually during the day. The growth and physiological welfare parameters of the fish were monitored, including the mortality, skin lesions, stress responses after confinement (plasma cortisol and glucose), and additional blood parameters. Tendentially, the most efficient growth in both the experiments was observed in the 0.5% groups, which performed slightly better than the controls (E1: 0.8% and E2: 3.2%) despite a lower nutrient content (p > 0.05). In E1, the negative skewness of the leptokurtic distribution also revealed the highest number of larger-sized fish per batch. Mortality was low in all the treatment groups (E1 control/0.5%/2.0%: 3.6%/4.9%/2.9%; E2 control/0.5%: 2.6%/5.5%). After only 29 d in E1, the number of skin lesions per fish decreased significantly (p < 0.05 between each of the 0.5% and 2.0% groups, compared to the control (E1 control/0.5%/2.0%: 1.2/0.8/0.8). In both E1 and E2, the number of lesions per fish decreased even further after 70 d, significantly between the treatment groups and the control (E1 control/0.5%/2.0%: 0.9/0.4/0.5 and E2 control/0.5%: 0.6/0.3). In E1, the cortisol and glucose concentrations increased strongly in all the groups due to the induced stress, whereas this was not evident in E2 based on the different sampling procedure. The additional blood parameters (aspartate aminotransferase, glutamate dehydrogenase, urea, calcium, phosphate, total protein, leucocytes, erythrocytes, hematocrit, cholesterol, triglycerides, sodium, potassium, and chloride) revealed no significant difference between the treatment groups in either experiment, indicating no negative effects of 1g557 on the organs or metabolism of the fish. Supplementation with 0.5% 1g557 in the common commercial feeds for African catfish increases growth performance (p > 0.05), reduces size variance, and supports fish welfare under different commercial aquaculture conditions in the present study.

Identifying the relative impact of process- and outcome-related team performance antecedents: a meta-analysis

PurposeThe purpose of this paper is to identify, through an exploratory meta-analysis, which process- and outcome-related antecedents have the strongest relationship to overall team performance. The secondary objective is to create an understanding of the extent to which relative research interest in each construct to date has aligned with its reported effects.Design/methodology/approachThis study uses a random-effects meta-analysis on studies that have measured the relationship between at least one process or outcome factor and overall team performance. The number of studies, effect size and between-study variances are captured and analyzed for each process/outcome factor. Prior literature has explored relationships between various process/outcome factors and overall team performance. This study expands on previous literature by examining a comprehensive set of process/outcome factors and their relative impact on overall team performance.FindingsA meta-analysis of 190 effect sizes extracted from 52 empirical studies over the past two decades (1999–2020) showed the specific process and outcome factors that most strongly contributed to overall team performance were efficiency, schedule and innovation. In addition, only a weak correlation was found between process and outcome factors’ relationships with overall team performance and how often they are studied in the research community.Originality/valueThis study contributes to the body of knowledge on team performance by examining prior research to identify the relevant impact of various process and outcome factors on overall team performance. In addition, this study also assesses the extent to which research interest in these factors has appeared to match their relative impact. Analyzing the relative impact of various process and outcome factors allows researchers and practitioners to better identify methods to create improvement in overall team performance. Based on the findings, prioritizing efficiency, schedule and innovation may promote overall team performance.

The Impact of Virtual Reality on Post-Compulsory Students’ Learning Outcomes: A Review with Meta-Analysis

Virtual reality provides learners with an opportunity to run through situations that could not be accessed in the real world, which makes this technology an attractive alternative or a supplement to conventional instruction. This integrative review sought to bring together the impacts of immersive interventions on post-compulsory student learning performance. Nine empirical studies resulted from the screening process on the basis of eligibility criteria. Overall, there was a low to moderate mean effect size using a random-effects model (Hedge’s g = 0.31 [-0.27, 0.90], p = 0.218) for the application of high-immersion activities to education. As in previous reviews on the topic, considerable variance in the effect sizes was detected, thus precluding conclusive statements on the effectiveness of virtual educational simulations for accelerating learning outcomes in post-secondary settings. Some implications of the analysis for the educational practice are provided.

Aircraft detection in satellite imagery using deep learning-based object detectors

Over the recent years, object detection in satellite imagery has become a crucial task in remote sensing applications. Specifically, the detection of aircraft is critical for military scenarios. Numerous computer vision techniques have been applied for this problem, however, robust and efficient detection of aircraft in satellite imagery poses several challenges, such as, variance of color, size, aspect ratio and orientation of aircraft and complex backgrounds. In this paper, we provide an in-depth review of deep learning methods for object detection applied to aircraft detection including both conventional and state-of-the-art techniques. We also provide a comprehensive experimental and comparative analysis of deep learning-based object detectors including Region-based CNN (RCNN), Fast RCNN, Faster RCNN and You Only Look Once (YOLO) encapsulating the most cited feature extraction networks including Alexnet, VGG-16, Resnet-18, Resnet-50, Resnet-101 and Inception-v3. The detailed quantitative comparison allows for selection of the most suitable set of object detector, backbone feature extraction network and hyperparameters for aircraft detection in satellite imagery with trade-off options between precision and detection time. The evaluation is based on mean average precision (mAP), precision versus recall, time complexity and computational complexity. Finally, we draw our conclusions and identify promising future work.

Effectiveness of Resistance Training on Fatigue in Patients Undergoing Cancer Treatment: A Meta-Analysis of Randomized Clinical Trials.

Objective To assess the effectiveness of the resistance training to improve fatigue levels in people with cancer who are enrolled in adjuvant and/or neoadjuvant treatment. Methods MEDLINE, Web of Science, Embase, SPORTDiscus, LILACS, CENTRAL, and CINAHL databases were searched from May to December 7, 2021. Randomized clinical trials (RCT) that evaluate the effects of resistance training on fatigue levels in people undergoing cancer treatment were included. The PEDro scale was considered to assess methodological quality of studies, and the evidence was summarized through the GRADE system. The standardized average differences, effect size, and inverse variance model for meta-analysis were calculated. Results Fifteen RCT for qualitative synthesis and thirteen for meta-analysis were selected. A moderate to high level of evidence of resistance training was identified to improve fatigue in people undergoing cancer treatment. Meta-analysis showed a significant reduction in fatigue (SMD = −0.31, CI 95% = −0.58, -0.12, P = 0.001) after 10 to 35 sessions of resistance training. Conclusion The 10 to 35 sessions of resistance training are effective in reducing fatigue level in cancer patients who are undergoing cancer treatment and have a moderate level of quality evidence.

Non-uniform metamorphosis underlies different development trajectories in hatchery-reared flathead grey mullet (Mugil cephalus)

The flathead grey mullet (Mugil cephalus) is at the focus of an intense domestication effort. However, despite significant advances, aquaculture of grey mullets is still based on capture of wild fingerlings in estuaries and stocking them into ponds. Such reliance on wild seed limits aquaculture production since it is highly seasonal, unpredictable, hinders genetic improvement programs and may negatively affect local capture fisheries. As captive breeding has been optimized for the species, to date, larval rearing remains the main challenge hindering the commercial production of captive-bred mullets. Here we set out to characterize larval development of grey mullets under captive conditions and to identify key developmental bottlenecks. By analyzing four larval batches from a commercial hatchery, we defined ten distinct developmental stages from hatching to the end of metamorphosis based on macroscopically observable morphological features. Using this developmental atlas to study development dynamics, we found that mullet larvae exhibit a biphasic growth profile with a 17-fold increase in growth rates at the onset of metamorphosis. Moreover, we found that within rearing batches, size variation almost doubles at metamorphosis, suggesting that the onset of metamorphosis is a critical step that increases variation by dictating different growth trajectories to early and late-metamorphosing larvae. By plotting the developmental stages against different morphometric parameters, we show here that age is a poor predictor of larval development due to large variations in development rates both within and between batches. We found that mullet larvae begin metamorphosis at a set size threshold of ~4.5 mm, however age at this threshold varies greatly even within batches. This age and size variance is further amplified by the aforementioned enhanced growth rates at metamorphosis and results in highly non-uniform fry, which complicate the rearing and weaning procedures. Understanding and treating the underlying causes for delayed metamorphosis are therefore considered important steps for the full domestication of the grey mullet.

Weak effects on growth and cannibalism under fluctuating temperatures in damselfly larvae

The Earth’s climate is changing with a trend towards higher mean temperatures and increased temperature fluctuations. Little attention has been paid to the effects of thermal variation on competition within species. Understanding the temperature-dependence of competition is important since it might affect dynamics within and between populations. In a laboratory experiment we investigated the effects of thermal variation on growth and cannibalism in larvae of a damselfly. The temperature treatments included three amplitudes between 20 and 26 °C with an average of 23 °C, and a constant control at 23 °C. Larvae were also raised at five constant temperatures for an estimation of the thermal performance curve, which showed that the thermal optimum for growth was 26.9 °C. Cannibalism was significantly positively correlated with initial body size variance. There was neither a difference among the temperature variation treatments, nor between the constant and the variation treatments in growth and cannibalism. Hence, positive and negative effects of temperature variation within the linear range of a species thermal performance curve might cancel each other out. Since our study mimicked natural temperature conditions, we suggest that the increase in temperature variation predicted by climate models will not necessarily differ from the effects without an increase in variation.

Accurate image-based CSF volume calculation of the lateral ventricles

The size/volume of the brain’s ventricles is essential in diagnosing and treating many neurological disorders, with various forms of hydrocephalus being some of the most common. Initial ventricular size and changes, if any, in response to disease progression or therapeutic intervention are monitored by serial imaging methods. Significant variance in ventricular size is readily noted, but small incremental changes can be challenging to appreciate. We have previously reported using artificial intelligence to determine ventricular volume. The values obtained were compared with those calculated using the inaccurate manual segmentation as the “gold standard”. This document introduces a strategy to measure ventricular volumes where manual segmentation is not employed to validate the estimations. Instead, we created 3D printed models that mimic the lateral ventricles and measured those 3D models’ volume with a tuned water displacement device. The 3D models are placed in a gel and taken to the magnetic resonance scanner. Images extracted from the phantoms are fed to an artificial intelligence-based algorithm. The volumes yielded by the automation must equal those yielded by water displacement to assert validation. Then, we provide certified volumes for subjects in the age range (1–114) months old and two hydrocephalus patients.

Eye Tracking Metrics Differences among Uninjured Adolescents and Those with Acute or Persistent Post-Concussion Symptoms.

Eye tracking assessments that include pupil metrics can supplement current clinical assessments of vision and autonomic dysfunction in concussed adolescents. This study aimed to explore the utility of a 220-second eye tracking assessment in distinguishing eye position, saccadic movement, and pupillary dynamics among uninjured adolescents, those with acute post-concussion symptoms (≤28 days since concussion), or those with persistent post-concussion symptoms (>28 days since concussion). Two hundred fifty-six eye tracking metrics across a prospective observational cohort of 180 uninjured adolescents recruited from a private suburban high school and 224 concussed adolescents, with acute or persistent symptoms, recruited from a tertiary care subspecialty concussion care program, 13 to 17 years old, from August 2017 to June 2021 were compared. Kruskal-Wallis tests were used, and Bonferroni corrections were applied to account for multiple comparisons and constructed receiver operating characteristic curves. Principal components analysis and regression models were applied to determine whether eye tracking metrics can augment clinical and demographic information in differentiating uninjured controls from concussed adolescents. Two metrics of eye position were worse in those with concussion than uninjured adolescents, and only one metric was significantly different between acute cases and persistent cases. Concussed adolescents had larger left and right mean, median, minimum, and maximum pupil size than uninjured controls. Concussed adolescents had greater differences in mean, median, and variance of left and right pupil size. Twelve metrics distinguished female concussed participants from uninjured; only four were associated with concussion status in males. A logistic regression model including clinical and demographics data and transformed eye tracking metrics performed better in predicting concussion status than clinical and demographics data alone. Objective eye tracking technology is capable of quickly identifying vision and pupillary disturbances after concussion, augmenting traditional clinical concussion assessments. These metrics may add to existing clinical practice for monitoring recovery in a heterogeneous adolescent concussion population.

The Correlation Between Self-Compassion and Life Satisfaction Varies Across Societal Individualism-Collectivism: A Three-Level Meta-Analysis

Self-compassion is positively correlated with life satisfaction. However, no previous work examined the cross-cultural difference regarding the effect size of this correlation. Using 79 independent samples ( N = 23,976) from 26 countries/regions, this three-level meta-analysis synthesized the effect sizes of their correlation, partitioned the between-study heterogeneity into the within- and between-country levels, and examined the moderating role of national culture according to the revised Minkov-Hofstede model. Results indicated that self-compassion was positively correlated with life satisfaction, with a moderate-to-large effect size (.40 ≤ r ≤ .47); 33.66% and 35.73% of the effect size variance could be attributed to the within-country and between-country heterogeneities; this correlation was stronger in samples collected from more individualistic societies. This study highlights that self-compassion may fit differently into different cultural realities and the importance of raising cultural awareness in future self-compassion research.

471 Ecg Gating Matters: Thoracic Aortic Size Varies By Cardiac Phase

Introduction: Thoracic aortic (TA) surveillance is commonly performed using computed tomography (CT). Variation in size between systole and diastole is known from echocardiographic data, however, in clinical practice most TA CT studies are not ECG-gated. We hypothesize that a significant variance in size exists on TA CT depending on the cardiac phase of acquisition.

Influence of spatial resolution in mesoscale modeling to reproduce wind power production in southern Mexico

Understanding near-surface wind variability is crucial to support wind power penetration on national electrical grids. High-resolution numerical simulations are often proposed as the best solution to study the fluctuation of wind resources. We compare Weather Research and Forecasting (WRF) and Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) bias-corrected wind speeds at hub height at different spatial resolutions and transform them to wind power production using a logistic power curve fitted to wind power measurements; the comparisons are based on error statistics and time series spectral analysis. The results show that numerical models reproduce observed wind speeds with correlations higher than 0.9 for WRF and 0.8 for MERRA-2. Moreover, annual observed wind power is reproduced with a maximum difference from observations of 0.011. However, each resolution reproduces the magnitudes of high-resolution periodicities differently so that there is a clear relationship between grid size and signal variance at high frequencies, as variance is indirectly proportional to frequency. This relationship is expected for wind speed, but based on results, it can be associated also for capacity factor sampled at hourly intervals. Therefore, the main benefit of high spatial resolution lies in the added variance in frequencies at sub-daily time scales. The study of the added value of high-resolution simulations in this region contributes to current efforts to develop reliable forecasting tools and strategies to support the development of wind power as a reliable energy source.

Prediction of fitness under different breeding designs in conservation programs

AbstractThe expected change in fitness under inbreeding due to deleterious recessive alleles depends on the amount of inbreeding load harbored by a population, that is, the load of deleterious recessive mutations concealed in the heterozygous state, and the opposing effect of genetic purging to remove such a load. This change in fitness can be thus predicted if an estimate of the inbreeding load and the purging coefficient (the parameter that quantifies the amount of purging) are available. These two parameters can be estimated in pedigreed populations, as has been shown for populations under random mating. A question arises whether these parameters can also be estimated under other breeding systems as well as whether they allow accurate prediction of the corresponding expected change in fitness. In conservation programs, it is usually recommended to preserve genetic diversity by equalizing contributions from parents to progeny and avoiding inbred matings. Regular systems of inbreeding have also been proposed as breeding conservation strategies to purge the inbreeding load. Using computer simulations, we first test a method to jointly estimate the initial inbreeding load and the purging coefficient in populations subjected to equalization of parental contributions, circular mating, and partial full‐sib mating. Then, using the expected values of the inbreeding coefficient and the variance of family size, as well as the estimates of the inbreeding load and the purging coefficient, we make simple predictions of the change in fitness over generations under these breeding systems and compare them with simulation results. We discuss how these fitness predictions can help undertaking conservation designs under different breeding scenarios.

The use of social robots with children and young people on the autism spectrum: A systematic review and meta-analysis.

Robot-mediated interventions show promise in supporting the development of children on the autism spectrum. In this systematic review and meta-analysis, we summarize key features of available evidence on robot-interventions for children and young people on the autism spectrum aged up to 18 years old, as well as consider their efficacy for specific domains of learning. PubMed, Scopus, EBSCOhost, Google Scholar, Cochrane Library, ACM Digital Library, and IEEE Xplore. Grey literature was also searched using PsycExtra, OpenGrey, British Library EThOS, and the British Library Catalogue. Databases were searched from inception until April (6th) 2021. Searches undertaken across seven databases yielded 2145 articles. Forty studies met our review inclusion criteria of which 17 were randomized control trials. The methodological quality of studies was conducted with the Quality Assessment Tool for Quantitative Studies. A narrative synthesis summarised the findings. A meta-analysis was conducted with 12 RCTs. Most interventions used humanoid (67%) robotic platforms, were predominantly based in clinics (37%) followed home, schools and laboratory (17% respectively) environments and targeted at improving social and communication skills (77%). Focusing on the most common outcomes, a random effects meta-analysis of RCTs showed that robot-mediated interventions significantly improved social functioning (g = 0.35 [95%CI 0.09 to 0.61; k = 7). By contrast, robots did not improve emotional (g = 0.63 [95%CI -1.43 to 2.69]; k = 2) or motor outcomes (g = -0.10 [95%CI -1.08 to 0.89]; k = 3), but the numbers of trials were very small. Meta-regression revealed that age accounted for almost one-third of the variance in effect sizes, with greater benefits being found in younger children. Overall, our findings support the use of robot-mediated interventions for autistic children and youth, and we propose several recommendations for future research to aid learning and enhance implementation in everyday settings. Our methods were preregistered in the PROSPERO database (CRD42019148981).

The Geochemical and Textural Transition between the Reef Package and its Hanging Wall, Stillwater Complex, Montana, USA

Abstract The highest grade Pd-Pt deposit on Earth, the J-M Reef, is hosted in coarse-grained to pegmatoidal cumulates called the Reef Package. Decades of mine development of the J-M Reef have revealed that a distinct discontinuity in rock fabric marks the top of the rock unit that hosts economic-grade sulfide mineralization. Mine geologists refer to this discontinuity as the hanging wall contact. This contact is the top of the Reef Package and is always locatable—either by the change in rock fabric or by distinctive hanging wall textures of silicate minerals—even when the reef sulfide mineralization is absent. This rather subtle textural feature is used reliably by mine geologists to follow the Reef during exploration and mine development. Although some high tenor sulfides (>1000 ppm Pd in 100% sulfide) are found sporadically in the hanging wall cumulates, these accumulations are too small to be economically viable. We present quantitative rock fabric data for four Reef Package and hanging wall intersections collected by electron back-scattered diffraction (EBSD). Plagioclase fabrics in the hanging wall are characterized by low variance in grain sizes and a strong point maximum concentration of (010) and a perpendicular girdle distribution of [100] consistent with an axial B-type fabric. These fabrics are indicative of either compaction of the crystal mush or crystal settling of nucleated crystals, the bulk magma in a chamber. Conversely, the fabrics of the Reef Package show higher variance grain in size distributions and weak to undeveloped preferred orientation of plagioclase crystals that did not undergo significant alignment or textural equilibration of plagioclase grains. The absence of foliation in the Reef Package stands in contrast both to hanging wall fabrics and to other reported EBSD datasets of plagioclase crystals orientations from the Bushveld Complex, the Skaergaard Intrusion, and the Rum Intrusion. Furthermore, plagioclase crystal size distributions for the Reef Package show flatter slopes and convex profiles with fewer crystals at small size fractions indicating the dissolution of small crystals during partial melting and textural coarsening (i.e. Ostwald ripening) and crystal growth. Crystal growth was favored over the nucleation of new crystals during prolonged interaction with a hot infiltrating melt into the resident mush resulting in the coarse-grained textures of the Reef Package cumulates. The hanging wall contact represents a boundary between partially remelted crystal mush of the Reef Package, where sulfide mineralization formed and accumulated, and an overlying essentially barren cumulate pile. The hanging wall cumulates formed following the cessation of footwall erosion and the resumption of crystal accumulation by normal magma chamber processes.

Trihalide Mixing by Size-Flexible H– Ions in Layered Ba2H3 (Cl, Br, I)

According to the Hume-Rothery rule, anions with a large difference in ionic radii, for example, chloride and iodide anions, cannot form solid solutions. In this study, we demonstrate that Ba2H3X (X = Cl, Br, or I) with the anti-Li3LaSb2-type structure, recently discovered to exhibit excellent hydride conductivity at low temperatures, can afford a trihalide solid solution containing a substantial amount of each halogen (e.g., Ba2H3Cl0.40Br0.35I0.25). The systematic study using Rietveld analysis and pair distribution function (PDF) analysis of synchrotron X-ray diffraction data revealed a significant deviation of the local structure from the average structural model for the solid solutions with fixed average radius but different size variances of X– anions. Analysis based on a triphasic model indicates that size-flexible H– anions play an important role in the formation of trihalide solid solutions, i.e., depending on the type of X, the HBa6 octahedron locally changes its size to accommodate the neighboring XBa6 octahedron. The chemical disorder in the hydride layer induced by the halide mixing reduces the activation barrier of the H– conduction, which is important for lowering operating temperatures. This study opens up the possibility to significantly expand the compositional space of anionic solid solutions by including hydride anion toward exploring novel functions.

Variations in Pupil Size Related to Memory for Recently Presented Words and Event Related Potentials.

Pupillometry has been found to be correlated with activity of cholinergic and noradrenergic neuromodulator systems. These systems regulate the level of cortical arousal and therefore perception, attention, and memory. Here, we tested how different types of pupil size variance (prestimulus baseline and prestimulus hippus power) may correlate with behavioral and event-related potentials (ERPs). We recorded pupil size and ERPs while participants were presented with a series of words and then asked whether the words had been in the initial list when they were later presented intermixed with unpresented words. We found that a smaller prestimulus baseline pupil size during the study phase was associated with better memory performance. Study items also evoked a larger P3 response at presentation and a greater old/new memory ERP effect at test when prestimulus pupil size was small rather than large. Prestimulus hippus power was found to be a between-subjects factor affecting the robustness of memory encoding with less power being associated with a greater old/new memory ERP effect. These results provide evidence relating memory and ERPs to variables defined on pupil size that are thought to reflect varying states of parasympathetic and sympathetic arousal.