Exploring Adaptive Virtual Reality Systems Used in Interventions for Children With Autism Spectrum Disorder: Systematic Review.

BACKGROUND: Adaptive systems serve to personalize interventions or training based on the user's needs and performance. The adaptation techniques rely on an underlying engine responsible for processing incoming data and generating tailored responses. Adaptive virtual reality (VR) systems have proven to be efficient in data monitoring and manipulation, as well as in their ability to transfer learning outcomes to the real world. In recent years, there has been significant interest in applying these systems to improve deficits associated with autism spectrum disorder (ASD). This is driven by the heterogeneity of symptoms among the population affected, highlighting the need for early customized interventions that target each individual's specific symptom configuration. OBJECTIVE: Recognizing these technology-driven therapeutic tools as efficient solutions, this systematic review aims to explore the application of adaptive VR systems in interventions for young individuals with ASD. METHODS: An extensive search was conducted across 3 different databases-PubMed Central, Scopus, and Web of Science-to identify relevant studies from approximately the past decade. Each author independently screened the included studies to assess the risk of bias. Studies satisfying the following inclusion criteria were selected: (1) the experimental tasks were delivered via a VR system, (2) system adaptation was automated, (3) the VR system was designed for intervention or training of ASD symptoms, (4) participants' ages ranged from 6 to 19 years, (5) the sample included at least 1 group with ASD, and (6) the adaptation strategy was thoroughly explained. Relevant information extracted from the studies included the sample size and mean age, the study's objectives, the skill trained, the implemented device, the adaptive strategy used, the engine techniques, and the signal used to adapt the systems. RESULTS: Overall, a total of 10 articles were included, involving 129 participants, 76% of whom had ASD. The studies included level switching (7/10, 70%), adaptive feedback strategies (9/10, 90%), and weighing the choice between a machine learning (ML) adaptive engine (3/10, 30%) and a non-ML adaptive engine (8/10, 80%). Adaptation signals ranged from explicit behavioral indicators (6/10, 60%), such as task performance, to implicit biosignals, such as motor movements, eye gaze, speech, and peripheral physiological responses (7/10, 70%). CONCLUSIONS: The findings reveal promising trends in the field, suggesting that automated VR systems leveraging real-time progression level switching and verbal feedback driven by non-ML techniques using explicit or, better yet, implicit signal processing have the potential to enhance interventions for young individuals with ASD. The limitations discussed mainly stem from the fact that no technological or automated tools were used to handle data, potentially introducing bias due to human error.

Virtual Reality Tennis Training: Performance Gains Derived from User Characteristics.

There is growing interest in virtual reality (VR) training among competitive athletes and casual sports players alike as a tool to supplement real-life play within a highly controlled, intellectually stimulating environment. We examined data from a commercially available, recently released VR software for tennis for changes in and correlates of performance. Two most frequently used tasks were evaluated-Baseline Center and Quick Volley, which include Efficiency (both), Concentration (both), and Reaction Time (Quick Volley only) subtasks. In all, 1,124 (Baseline Center) and 745 (Quick Volley) users met inclusion criteria (completed more than four trials; active sometime between November 2022 and July 2023). We found that most users were male adults and were about evenly split between advanced/pro users and intermediate/beginner users. Two or three trajectories emerged across the subtasks. Performance gains were most pronounced on movement efficiency, especially early on. Adult users generally exhibited more improvement than junior users. Additionally, women and right-handed users improved more on Baseline Center subtasks, and advanced/pro users did better than intermediate/beginner users on Quick Volley subtasks. We discuss that, despite strong performance gains within VR environment, VR training may still reflect in better real-world performance, may increase confidence and accuracy of relevant movement, lower risk of injury, and present a welcome diversion from a potential monotony of performing sport-related tasks in purely real-world settings. Future research should explore the extent to which VR training transfers to real-world performance.

Feeding levels during early gestation in a group-housing system for primiparous sows: Impact on piglet birthweight and litter uniformity.

Objective: The current study investigated the impacts of different feeding regimes during early gestation on conception rate, litter traits, piglet birthweight, and litter uniformity in primiparous sows. Methods: In total, 108 primiparous sows were inseminated and assigned to either a standard (1.9±0.5 kg/day, S) or high (2.9±0.8 kg/day, H) feeding levels during the first 35 days of gestation. The feeding regimes were categorized based on periods of gestation: 1 to 3, 4 to 15, and 16 to 35 days, resulting in four groups: SSS (n=26), SSH (n=28), SHH (n=28), and HHH (n=26). Afterwards, sows were placed into a group-housed system equipped with electronic sow feeders. The sows were weighed and assessed for backfat thickness and loin muscle depth at 0 and 35 days of gestation. At farrowing, data were collected on the total number of piglets born per litter (TB), piglet birthweights, and the coefficient of variation of piglet birthweights. Results: On average, sows gained 22.5±21.6 kg during the first 35 days of gestation, showing a positive correlation with backfat gain (r=0.954, p=0.006). The backfat gain in the HHH group was higher than in the SSS (p=0.016) and the SSH groups (p=0.023), but did not differ from the SHH group (p=0.684). Conception rates did not show differences among the feeding regimes (p>0.05). Individual piglet birthweights in the HHH group were higher than those in the SSH group (p<0.001). Likewise, the percentage of piglets with birthweights <1000 g in the HHH group was lower than that in the SSH group (p<0.001). However, the variation of piglet birthweight did not differ among the groups (p>0.05). Conclusion: Increasing feeding levels in primiparous sows in a group-housed system during early pregnancy can effectively restore their body condition without any detrimental effects on subsequent litters.

Unearthing who and Y at Harewood Cemetery and inference of George Washington's Y-chromosomal haplotype.

An excavation conducted at Harewood Cemetery to identify the unmarked grave of Samuel Washington resulted in the discovery of burials presumably belonging to George Washington's paternal grandnephews and their mother, Lucy Payne. To confirm their identities this study examined Y-chromosomal, mitochondrial, and autosomal DNA from the burials and a living Washington descendant. The burial's Y-STR profile was compared to FamilyTreeDNA's database, which resulted in a one-step difference from the living descendant and an exact match to another Washington. A more complete Y-STR and Y-SNP profile from the descendant was inferred to be the Washington Y profile. Kinship comparisons performed in relation to the descendant, who is a 4th and 5th degree relative of the putative individuals, resulted in >37,000 overlapping autosomal SNPs and strong statistical support with likelihood ratios exceeding one billion. This study highlights the benefits of a multi-marker approach for kinship prediction and DNA-assisted identification of historical remains.

Gilts prefer an open pen to a stall.

Stalls or crates are a very common type of housing used on pig farms that restrict an animal's movement. How this confinement impacts the animal's affective states is seldom investigated. We conducted a preference test over 7 days where trios of gilts (n = 10 trios, 27.4 ± 1.5 weeks old) had free access between individual self-locking stalls (~ 1.2 m2) and a shared open area allowing 2.8 m2/animal (71% of total area). Gilts had access to ad libitum feed and water both inside the crates and in the open area. After 7 days, personality traits of the animals were assessed with open field (OF) and novel object (NO) tests. Principal Component Analysis (PCA) yielded two main components, which we defined as Passivity and Engagement. The median time spent outside the crate was 95.2% as 21/29 of the gilts exhibited a significant preference for pen over crate during the 7-day trial (p < 0.05). Passivity had no relationship with time spent in the open area, but engagement during OF/NO was associated with less use of the open area (OR = 0.39, 95CI = [0.25, 0.60]). Interestingly, gilts were likely to spend less time in the open area at nighttime compared to daytime (Odds Ratio = 0.49, 95CI = [0.40, 0.60]), as well as experimental days passed (OR = 0.70, 95CI = [0.66, 0.73]). During the first daytime and nighttime, 1/29 and 2/29 animals preferred the crate respectively, whereas by the last daytime and nighttime 5 and 9 gilts preferred the crate respectively (p < 0.05). While both intrinsic (personality) and extrinsic (time of day, experimental day) factors appear to influence the gilt's housing preferences, most gilts significantly prefer an open area to a crate when free access is provided between the two. A smaller subpopulation of animals developed a preference for stalls but still utilize both the stall and the pen throughout the day.

A systematic approach to defining and verifying descriptors used in the Qualitative Behavioural Assessment of sows.

Qualitative Behaviour Assessment (QBA) is a welfare evaluation tool that uses a holistic approach to capturing an animal's emotional state. Lists of QBA descriptors validated to assess pig welfare exist, but their definitions are often not described in peer-reviewed literature and the processes used to develop definitions are lacking. The objective of this study is to detail a systematic approach to creating clear definitions for a pre-existing fixed list of QBA descriptors and test their application. A fixed list of 20 descriptors from the EU Welfare Quality® assessment protocol for pigs was modified, and ten pig experts were recruited to assist with defining these descriptors in a focus group-style discussion. Half of the experts involved in creating descriptor definitions partook in a subsequent step, where the newly developed definitions were tested by implementing QBA on a video library of post-weaned sows selected to capture the breadth of sow behaviour. Experts displayed excellent agreement in identifying a PCA dimension interpreted as the valence of descriptors and good agreement for another reflecting arousal. Inter-observer reliability was also measured for each descriptor. Only two descriptors exhibited less than moderate agreement between experts whereas half of the descriptors evoked substantial agreement or better. These findings support our process to delineate clear definitions for a fixed list of QBA descriptors in pigs. This study is the first of its kind detailing the in-depth process of creating and verifying descriptor definitions for future use in sow welfare assessment.

Complexity synchronization in emergent intelligence.

In this work, we use a simple multi-agent-based-model (MABM) of a social network, implementing selfish algorithm (SA) agents, to create an adaptive environment and show, using a modified diffusion entropy analysis (DEA), that the mutual-adaptive interaction between the parts of such a network manifests complexity synchronization (CS). CS has been shown to exist by processing simultaneously measured time series from among organ-networks (ONs) of the brain (neurophysiology), lungs (respiration), and heart (cardiovascular reactivity) and to be explained theoretically as a synchronization of the multifractal dimension (MFD) scaling parameters characterizing each time series. Herein, we find the same kind of CS in the emergent intelligence of groups formed in a self-organized social interaction without macroscopic control but with biased self-interest between two groups of agents playing an anti-coordination game. This computational result strongly suggests the existence of the same CS in real-world social phenomena and in human-machine interactions as that found empirically in ONs.

Ad libitum feeding systems for lactating sows: effects on productivity and welfare of sows and piglets.

The nutritional requirements of sows change during lactation and thus require adapted and dynamic feeding regimes that consider the sows' behavioral needs and production traits. The present study evaluated the effect of four different feeding systems on productivity and aspects of the welfare of 61 sows and their piglets during lactation. A non-ad libitum system (CON) was compared with two computer-monitored (COMP, COMP + ) ad libitum feeding systems, that allowed sows to access feed via displacement of an electronic sensor, as well as a third purely mechanical ad libitum feeding system (MECH). Daily feed disappearance, piglet growth, piglet growth per feed disappearance as well as sows' weight and conception rate were recorded. Health indicators of sows and piglets were scored as well as sow behavior analyzed for a total of 96 hours/sow from video recordings taken on days 2-4 and 23 postfarrowing (n = 35 sows). Sows from all three ad libitum systems (COMP, COMP+, MECH) showed a lower feed disappearance than CON (P < 0.01). Additionally, average daily piglet growth tended to be higher (P = 0.05) and piglet growth per sow feed disappearance was significantly higher in all three ad libitum systems than in CON (P < 0.01). Piglet mortality, sow weight loss and subsequent conception rates did not differ between treatment groups. Piglets in COMP and COMP + had fewer head lesions (P = 0.01). Sows in all three ad libitum systems spent more time with their head in the trough than in the non-ad libitum system (P < 0.01). Occurrence of sow stereotypies (vacuum chewing, biting fixtures) was rare (typically < 2% of scans) and did not differ between treatments. Our data suggest that sows fed ad libitum eat what they need and can convert feed more efficiently into the piglets' growth without additional weight loss. Furthermore, the increased time sows spent in ad libitum systems with their head in the trough points toward longer feeding times, which might be beneficial in terms of meeting pigs' behavioral need to forage. Taken together, our initial studies on sow feeding behavior and feed efficiency will benefit the development of new lactation feeding systems that promise to improve animal welfare and productivity while reducing feed costs.

High-dimensional Metaverse Platforms and the Virtually Extended Self.

The study of cognition has traditionally used low-dimensional measures and stimulus presentations that emphasize laboratory control over high-dimensional (i.e., ecologically valid) tools that reflect the activities and interactions in everyday living. Although controlled experimental presentations in laboratories have enhanced our understanding of cognition for both healthy and clinical cohorts, high dimensionality may extend reality and cognition. High-dimensional Metaverse approaches use extended reality (XR) platforms with dynamic stimulus presentations that couple humans and simulation technologies to extend cognition. The plan for this paper is as follows: The "Extending from low to high-dimensional studies of cognition" section discusses current needs for high-dimensional stimulus presentations that reflect everyday cognitive activities. In the "Algorithmic devices and digital extension of cognition" section, technologies of the extended mind are introduced with the Metaverse as a candidate cognitive process for extension. Next, in the "A neurocognitive framework for understanding technologies of the extended mind" section, a framework and model are proposed for understanding the neural correlates of human technology couplings in terms of automatic algorithmic processes (limbic-ventral striatal loop); reflective cognition (prefrontal-dorsal striatal loop); and algorithmic processing (insular cortex). The algorithmic processes of human-technology interactions can, over time, become an automated and algorithmic coupling of brain and technology. The manuscript ends with a brief summary and discussion of the ways in which the Metaverse can be used for studying how persons respond to high-dimensional stimuli in simulations that approximate real-world activities and interactions.

Cognitive tasks as measures of pig welfare: a systematic review.

Cognitive approaches are increasingly used to assess animal welfare, but no systematic review has been conducted on pigs despite their cognitive capacities. Our aims were two-fold: first, to assess the popularity and heterogeneity of this approach by quantifying the different cognitive tasks used and welfare interventions studied. The second was to assess how often results from cognitive tasks supported treatment effects. The search yielded 36 studies that met our criteria. Eleven different cognitive tasks were applied (three most common: judgment bias, learned approach/aversion, and holeboard). Welfare interventions investigated were also diverse: the impact of 19 other different events/conditions/states were reported (most common: housing enrichment). We defined "supportive" as the observation of a significant difference between treatment groups consistent with an author's expectation or hypothesis. Supportive findings were reported in 44% of papers. Interventions yielded no significant difference in 33% of studies. In another 21% of reports, outcomes were mixed and a single study refuted the author's predictions. When considering specific cognitive tasks, authors' predictions of welfare differences were supported most often when using learned approach/aversion (55% of these studies). Similar supportive results were observed less commonly (40% each) when using judgment bias and holeboard tests. Analysis of additional concomitant measures of welfare (health, physiology or behavior) revealed that behavioral measures were most frequently supportive of author's expectations (41%) as well as often matching the actual outcomes of these cognitive tasks (47%). This systematic review highlights the growing popularity of cognitive tasks as measures of pig welfare. However, overall rates of supportive results, i.e., changes in performance on cognitive tasks due to welfare interventions, have been limited so far, even for the most employed task, judgment bias. The numerous different combinations of experimental paradigms and welfare interventions reported in the literature creates challenges for a critical meta-analysis of the field especially in evaluating the efficiency of specific cognitive tasks in assessing animal welfare. This work also highlights important knowledge gaps in the use of cognitive tasks that will require both further validation as well as novel innovation to ensure that their potential is fully realized in the measurement of pig welfare.

A virtual reality paradigm with dynamic scene stimuli for use in memory research.

Episodic memory may essentially be memory for one's place within a temporally unfolding scene from a first-person perspective. Given this, pervasively used static stimuli may only capture one small part of episodic memory. A promising approach for advancing the study of episodic memory is immersing participants within varying scenes from a first-person perspective. We present a pool of distinct scene stimuli for use in virtual environments and a paradigm that is implementable across varying levels of immersion on multiple virtual reality (VR) platforms and adaptable to studying various aspects of scene and episodic memory. In our task, participants are placed within a series of virtual environments from a first-person perspective and guided through a virtual tour of scenes during a study phase and a test phase. In the test phase, some scenes share a spatial layout with studied scenes; others are completely novel. In three experiments with varying degrees of immersion, we measure scene recall, scene familiarity-detection during recall failure, the subjective experience of déjà vu, the ability to predict the next turn on a tour, the subjective sense of being able to predict the next turn on a tour, and the factors that influence memory search and the inclination to generate candidate recollective information. The level of first-person immersion mattered to multiple facets of episodic memory. The paradigm presents a useful means of advancing mechanistic understanding of how memory operates in realistic dynamic scene environments, including in combination with cognitive neuroscience methods such as functional magnetic resonance imaging and electrophysiology.

Performance on a virtual environment shopping task and adaptive functioning among older adults.

Neuropsychologists are often asked to evaluate patients' functional capacities, yet traditional neuropsychological tests have limited correspondence with real-world outcomes. The Virtual Environment Grocery Store (VEGS) is a virtual environment that simulates shopping tasks. The purpose of this study was to investigate the relationship between older adults' performance on the VEGS in relation to their self-reported adaptive functioning as well as performance on a performance-based adaptive functioning measure. Older adults (n = 98; age 65-90, M = 75.82, SD = 6.27) were administered the VEGS, the Instrumental Activities of Daily Living Scale (IADLS), and the Texas Functional Living Scale (TFLS). Neither premorbid functioning nor the VEGS variables were associated with self-rated adaptive functioning. However, all three VEGS variables were associated with performance-based adaptive functioning (i.e., the TFLS). Performance on the VEGS measure of correct items in the shopping cart explained 13.9% of the variance in performance on the performance-based adaptive functioning task. Whether the participant picked up the VEGS prescription explained 12.6% of the variance in performance on the performance-based adaptive functioning task. Performance on VEGS long delay free recall explained 35.1% of the variance in performance on the performance-based adaptive functioning task. These results suggest that the VEGS demonstrates value in predicting older adults' functional capacities.

Neural and behavioral adaptations to frontal theta neurofeedback training: A proof of concept study.

Previous neurofeedback research has shown training-related frontal theta increases and performance improvements on some executive tasks in real feedback versus sham control groups. However, typical sham control groups receive false or non-contingent feedback, making it difficult to know whether observed differences between groups are associated with accurate contingent feedback or other cognitive mechanisms (motivation, control strategies, attentional engagement, fatigue, etc.). To address this question, we investigated differences between two frontal theta training groups, each receiving accurate contingent feedback, but with different top-down goals: (1) increase and (2) alternate increase/decrease. We hypothesized that the increase group would exhibit greater increases in frontal theta compared to the alternate group, which would exhibit lower frontal theta during down- versus up-modulation blocks over sessions. We also hypothesized that the alternate group would exhibit greater performance improvements on a Go-NoGo shooting task requiring alterations in behavioral activation and inhibition, as the alternate group would be trained with greater task specificity, suggesting that receiving accurate contingent feedback may be the more salient learning mechanism underlying frontal theta neurofeedback training gains. Thirty young healthy volunteers were randomly assigned to increase or alternate groups. Training consisted of an orientation session, five neurofeedback training sessions (six blocks of six 30-s trials of FCz theta modulation (4-7 Hz) separated by 10-s rest intervals), and six Go-NoGo testing sessions (four blocks of 90 trials in both Low and High time-stress conditions). Multilevel modeling revealed greater frontal theta increases in the alternate group over training sessions. Further, Go-NoGo task performance increased at a greater rate in the increase group (accuracy and reaction time, but not commission errors). Overall, these results reject our hypotheses and suggest that changes in frontal theta and performance outcomes were not explained by reinforcement learning afforded by accurate contingent feedback. We discuss our findings in terms of alternative conceptual and methodological considerations, as well as limitations of this research.

Pen Versus Crate: A Comparative Study on the Effects of Different Farrowing Systems on Farrowing Performance, Colostrum Yield and Piglet Preweaning Mortality in Sows under Tropical Conditions.

The present study was performed to determine the farrowing performance of sows, newborn piglet characteristics, colostrum yield, milk yield and piglet preweaning mortality in a free-farrowing pen compared to a conventional farrowing crate system in a tropical environment. A total of 92 sows and 1344 piglets were included in the study. The sows were allocated by parity into two farrowing systems, either a free-farrowing pen (n = 54 sows and 805 piglets) or a crate (n = 38 sows and 539 piglets). Backfat thickness and loin muscle depth of sows at 109.0 ± 3.0 days of gestation were measured. Reproductive performance data including total number of piglets born (TB), number of piglets born alive (BA), percentage of stillborn piglets (SB) and percentage of mummified foetuses (MF) per litter, farrowing duration, piglet expulsion interval, time from onset of farrowing to the last placental expulsion, piglet preweaning mortality rate, percentage of piglets crushed by sows and number of piglets at weaning were analysed. In addition, piglet colostrum intake, colostrum yield, Brix index and milk yield of sows were evaluated. On average, TB, BA, farrowing duration, colostrum yield and milk yield during 3 to 10 and 10 to 17 days of lactation were 14.7 ± 2.8, 12.8 ± 3.1, 213.2 ± 142.2 min, 5.3 ± 1.4 kg, 8.6 ± 1.5 kg, and 10.4 ± 2.2 kg, respectively. Sows kept in the free-farrowing pen tended to produce more colostrum than crated sows (5.5 ± 0.2 vs. 4.9 ± 0.2 kg, p = 0.080). Piglets born in the free-farrowing pen had a higher colostrum intake than those in the crate system (437.0 ± 6.9 and 411.7 ± 8.3 g, p = 0.019). However, the piglet preweaning mortality rate (26.8 ± 2.9 vs. 17.0 ± 3.8, p = 0.045) and the proportion of piglets crushed by sows (13.1 ± 2.1 vs. 5.8 ± 2.7, p = 0.037) in the free-farrowing pen were higher than those in the crate system. Interestingly, in the free-farrowing pen, piglet preweaning mortality rate in sows with high backfat thickness was higher than that in sows with moderate (37.8 ± 5.1% vs. 21.6 ± 3.6%, p = 0.011) and low (21.0 ± 6.2%, p = 0.038) backfat thickness. Moreover, the incidence of crushing in sows with high backfat thickness was higher in the free-farrowing pen than in the crate system (17.6 ± 3.6 vs. 4.0 ± 5.7, p = 0.049), but this difference was not detected for sows with moderate and low backfat thickness (p > 0.05). Milk yield of sows during 3 to 10 days (8.6 ± 0.2 vs. 8.6 ± 2.3, p > 0.05) and 10 to 17 days (10.2 ± 0.3 vs. 10.4 ± 0.4, p > 0.05) did not differ between the two farrowing systems. In conclusion, piglets born in the free-farrowing pen had a higher colostrum intake than those in the crate system. However, the piglet preweaning mortality rate and the proportion of piglets crushed by sows in the free-farrowing pen were higher than in the crate system. Interestingly, a high proportion of piglet preweaning mortality in the free-farrowing system was detected only in sows with high backfat thickness before farrowing but not in those with low and moderate backfat thickness. Therefore, additional management in sows with high backfat thickness (>24 mm) before farrowing should be considered to avoid the crushing of piglets by sows.

Prospective Study Evaluating Whether Standard Peripheral Intravenous Catheters Can Be Used for Blood Collection Throughout Hospital Stay.

Blood collection via venipuncture is the most common invasive procedure for inpatients, who experience an average of 1.6 to 2.2 blood collection episodes per day, for a total of approximately 450 million in US hospitals annually. In addition to being painful, venipuncture incurs the risk of vessel depletion, infection, and staff needlestick injury. A possible alternative is to use peripheral intravenous catheters (PIVCs), because PIVCs are placed in the majority of patients admitted to the hospital. Although there are anecdotal accounts of successfully using PIVCs for inpatient blood collection, the utility of this method has not been rigorously studied. The authors conducted a single-center prospective study among inpatients to evaluate blood collection success, defined as sufficient sample volume (4 mL) and no or minimal hemolysis, in PIVCs with a dwell time between 12 and 87 hours. Only 27% (28/105) of aspiration attempts were successful within this time frame. There was no difference in success rate with respect to PIVC dwell time, gauge, or location. These findings highlight the continued need for innovative, alternative solutions to meet the high demand for inpatient blood collection.

Opening a conceptual space for metamemory experience.

The experiences associated with remembering, including metamemory feelings about the act of remembering and attempts at remembering, are not often integrated into general accounts of memory. For example, David Rubin (2022) proposes a unified, three-dimensional conceptual space for mapping memory states, a map that does not systematically specify metamemory feelings. Drawing on Rubin's model, we define a distinct role for metamemory in relation to first-order memory content. We propose a fourth dimension for the model and support the proposal with conceptual, neurocognitive, and clinical lines of reasoning. We use the modified model to illustrate several cases, and show how it helps to conceptualize a new category of memory state: autonoetic knowing, exemplified by déjà vu. We also caution not to assume that memory experience is directly correlated with or caused by memory content, an assumption Tulving (1989) labeled the doctrine of concordance.

International Survey of Practice for Prophylactic Systemic Antibiotic Therapy in Hip and Knee Arthroplasty.

(1) Background: Prophylactic systemic antibiotics are acknowledged to be an important part of mitigating prosthetic joint infections. Controversy persists regarding optimal antibiotic regimes. We sought to evaluate current international antibiotics guidelines for total joint arthroplasty (TJA) of the hip and knee. (2) Methods: 42 arthroplasty societies across 6 continents were contacted and their published literature reviewed. (3) Results: 17 societies had guidelines; of which 11 recommended an antibiotic agent or antibiotic class (10-cephalosporin; 1-cloxacillin); 15 recommended antibiotic infusion within an hour of incision and 10 advised for post-operative doses (8-up to 24 h; 1-up to 36 h; 1-up to 48 h). (4) Conclusions: Prophylactic antibiotic guidelines for TJA are often absent or heterogenous in their advice.

Factor analysis of the virtual reality Stroop task.

INTRODUCTION: Virtual reality (VR) offers neuropsychologists high dimensional (3D) platforms for administering cognitive tasks that balance experimental control with simulations of naturalistic activities. A virtual reality version of the Stroop task, the Virtual Reality Stroop Task (VRST), was developed that leverages technological advances to enhance the ecological validity of neuropsychological assessments. The high mobility multipurpose wheeled vehicle (HMMWV) version of the VRST includes high arousal (ambush) and low arousal (safe) zones was employed in this study. This version of the VRST contains both cognitive (Stroop) and affective (arousal) components. While the VRST has been shown to have good construct validity, the factor structure has yet to be explored. This study aimed to examine the factor structure of the VRST and compare the results with a lower dimensional (2D) computer-automated Stroop task (i.e., the Automated Neuropsychological Assessment Metrics - ANAM). METHOD: Data was drawn from college-aged students who completed the VRST and ANAM Stroop tasks (N = 115). Factor analyses utilized principal axis factoring (PAF), and output variables included percent of correct responses and response times the VRST and ANAM Stroop tasks. RESULTS: Results indicated that both Stroop tasks had two-factor solutions. Factor one measured response times and factor two measured accuracy. While factors respective of speed and accuracy factors were correlated across assessment modalities, within assessment factor correlations were low. CONCLUSIONS: The factors possibly indicated participants response styles in that they either focus on responding accurately or responding quickly to stimuli. Therefore, including throughput in future research examining either the ANAM Stroop task or VRST may provide useful insight into participant performance. Finally, because similar factor structures were observed for both the VRST and ANAM Stroop task this study provided additional support for the construct validity of a higher dimensional Stroop task, the VRST.

A systematic review of the impact of housing on sow welfare during post-weaning and early pregnancy periods.

Breeder animals are an important focus in farm animal welfare assessments as they typically live the longest lives and are at the greatest risk for suffering due to their longevity. For breeding pigs, the time between the end of lactation (post-weaning) and the implantation of embryos (early gestation) is very dynamic from both a physiological and husbandry perspective. However, research to date is limited on how best to house and manage sows during this critical period of their production cycle from a welfare perspective. Previous animal-based welfare outcome measures were restricted to certain health, behavioral and physiological indicators. This systematic review used Web of Science to make in-depth comparisons among welfare-based studies that focus on sow housing during the post-weaning and early pregnancy period to identify important knowledge gaps. Only a small number of studies (n = 27) were found that met our systematic search criteria. Compared to stalls, group housing requires mixing of animals and always triggers more aggression and skin lesions at the time of mixing. The predominant use of health and physiological indicators constrained the animal-based welfare outcomes in these studies. Thus, what type of housing yields the best overall welfare outcome remains to be elucidated as none of the studies found explored the mental wellbeing of sows during this period. This systematic review defines a critical knowledge gap regarding the full impact of housing on the welfare of post-weaning and early gestation sows. This gap, and thus the true welfare impact of sow housing, will only be addressed by the use of novel, more holistic assessment methods that also capture the psychological state of the sow.