Double Ventricular Response with Aberrant Conduction Leading to Ventricular Dysfunction.

Double ventricular response (DVR), where a single P wave results in two QRS complexes, is a rare presentation of dual AV node physiology. It has been associated with ventricular dysfunction in the setting of incessant tachycardia. We present the case of an otherwise healthy adolescent who had frequent DVR without tachycardia leading to left ventricular dysfunction. Slow pathway modification led to a significant reduction in ectopy and normalization of ventricular function. This highlights that DVR without tachycardia might lead to ventricular dysfunction in pediatric patients. Slow pathway modification with reduction of ectopy may be sufficient to restore ventricular function.

Exploring the Impact of External Facilitation Using Evidence-Based Implementation Strategies for Increasing Motivational Interviewing Capacity Among Outpatient Substance Use Disorder (SUD) Treatment Providers.

The large majority of individuals who access substance use disorders (SUD) treatment do not receive evidence-based care. Little attention has been paid to the notion that the scale-up of evidence-based practices (EBPs) has been limited in large part due to a weakness in the "distribution system" for bringing new innovations to the attention of practitioners and into practice settings. This study explores the impact of the Training and Practice Implementation Institute (TPII; funded by the New York City Department of Health and Mental Hygiene), an intensive technical assistance initiative that offers external facilitation to outpatient SUD treatment providers via the incorporation of multiple evidence-based implementation strategies to enhance the practice of motivational interviewing (MI). Findings from this study show that staff completed a large majority (86%) of required training/technical assistance (TTA) activities across the 9-month implementation period, demonstrating a high level of engagement among staff and the feasibility of externally facilitated intensive TTA delivered to community-based organizations for the purpose of enhancing implementation of MI for SUDs. Results also show statistically significant improvements in the delivery of MI's technical components among staff, though did not reveal corresponding improvements in the delivery of MI's relational components. An understanding of the potential return on investment associated with externally facilitated TA, offers organizations an opportunity to inform the allocation of limited resources to areas where they will have the greatest impact and ultimately improve the quality and efficacy of services.

The UCLA Cosmochemistry Database.

The UCLA Cosmochemistry Database was initiated as part of a data-rescue and -storage project aimed at archiving a variety of cosmochemical data acquired at University of California, Los Angeles (UCLA). The data collection includes elemental compositions of extraterrestrial materials analyzed by UCLA cosmochemists over the last five decades. The analytical techniques include atomic absorption spectrometry (AAS) and neutron activation analysis (NAA) at UCLA. The data collection is stored on the Astromaterials Data System (Astromat). We provide both interactive tables and downloadable datasheets for users to access all data. The UCLA Cosmochemistry Database archives cosmochemical data that are essential tools for increasing our understanding of the nature and origin of extraterrestrial materials. Future studies can reference the data collection in the examination, analysis, and classification of newly acquired extraterrestrial samples.

As clear as glass: How figurativeness and familiarity impact simile processing in readers with and without dyslexia.

For skilled readers, idiomatic language confers faster access to overall meaning compared with non-idiomatic language, with a processing advantage for figurative over literal interpretation. However, currently very little research exists to elucidate whether atypical readers-such as those with developmental dyslexia-show such a processing advantage for figurative interpretations of idioms, or whether their reading impairment implicates subtle differences in semantic access. We wanted to know whether an initial figurative interpretation of similes, for both typical and dyslexic readers, is dependent on familiarity. Here, we tracked typical and dyslexic readers' eye movements as they read sentences containing similes (e.g., as cold as ice), orthogonally manipulated for novelty (e.g., familiar: as cold as ice, novel: as cold as snow) and figurativeness (e.g., literal: as cold as ice [low temperature], figurative: as cold as ice [emotionally distant]), with figurativeness being defined by the sentence context. Both participant groups exhibited a processing advantage for familiar and figurative similes over novel and literal similes. However, compared with typical readers, participants with dyslexia had greater difficulty processing similes both when they were unfamiliar and when the context biased the simile meaning towards a literal rather than a figurative interpretation. Our findings suggest a semantic processing anomaly in dyslexic readers, which we discuss in light of recent literature on sentence-level semantic processing.

The Role of Prominence in Activating Focused Words and Their Alternatives in Mandarin: Evidence from Lexical Priming and Recognition Memory.

When a sentence is produced with contrastive prosodic prominence, the word that carries the prominence becomes more salient, and alternatives to that word are usually implied. In processing, this implies that focused words and their alternatives should be more strongly activated. Previous research on focus processing has primarily been confined to Germanic languages. The current paper reports on two experiments investigating the role of prosodic prominence in immediate (Experiment 1) and long-term processing (Experiment 2) of focused words and focus alternatives in Mandarin. Prosodic prominence was effective in activating focused words and their alternatives. In the memory task, this facilitation effect was only found toward the beginning of the experiment. We attribute this difference to task-related adaptive use of prosodic prominence in utterance processing. This research sheds light on whether, when, and how listeners use prosodic prominence to identify important information and to evoke alternatives during sentence comprehension.

Investigating distortions in perceptual stability during different self-movements using virtual reality.

Using immersive virtual reality (the HTC Vive Head Mounted Display), we measured both bias and sensitivity when making judgements about the scene stability of a target object during both active (self-propelled) and passive (experimenter-propelled) observer movements. This was repeated in the same group of 16 participants for three different observer-target movement conditions in which the instability of a target was yoked to the movement of the observer. We found that in all movement conditions that the target needed to move with (in the same direction) as the participant to be perceived as scene-stable. Consistent with the presence of additional available information (efference copy) about self-movement during active conditions, biases were smaller and sensitivities to instability were higher in these relative to passive conditions. However, the presence of efference copy was clearly not sufficient to completely eliminate the bias and we suggest that the presence of additional visual information about self-movement is also critical. We found some (albeit limited) evidence for correlation between appropriate metrics across different movement conditions. These results extend previous findings, providing evidence for consistency of biases across different movement types, suggestive of common processing underpinning perceptual stability judgements.

Inequitable access: factors associated with incomplete referrals to paediatric cardiology.

OBJECTIVE: To assess the variables associated with incomplete and unscheduled cardiology clinic visits among referred children with a focus on equity gaps. STUDY DESIGN: We conducted a retrospective chart review for patients less than 18 years of age who were referred to cardiology clinics at a single quaternary referral centre from 2017 to 2019. We collected patient demographic data including race, an index of neighbourhood socio-economic deprivation linked to a patient's geocoded address, referral information, and cardiology clinic information. The primary outcome was an incomplete clinic visit. The secondary outcome was an unscheduled appointment. Independent associations were identified using multivariable logistic regression. RESULTS: There were 10,610 new referrals; 6954 (66%) completed new cardiology clinic visits. Black race (OR 1.41; 95% CI 1.22-1.63), public insurance (OR 1.29; 95% CI 1.14-1.46), and a higher deprivation index (OR 1.32; 95% CI 1.08-1.61) were associated with higher odds of incomplete visit compared to the respective reference groups of White race, private insurance, and a lower deprivation index. The findings for unscheduled visit were similar. A shorter time elapsed from the initial referral to when the appointment was made was associated with lower odds of incomplete visit (OR 0.62; 95% CI 0.52-0.74). CONCLUSION: Race, insurance type, neighbourhood deprivation, and time from referral date to appointment made were each associated with incomplete referrals to paediatric cardiology. Interventions directed to understand such associations and respond accordingly could help to equitably improve referral completion.

The impact of choice discriminability and outcome valence on visual decision making under risk.

Much of human activity involves perceptual or perceptuo-motor choice between options with uncertain outcomes. Previous research suggests that decisions in these contexts can be near-optimal in some circumstances but can also be significantly biased. Here we investigate how biases might depend on: i) discriminability of available choice outcomes, adjusted by manipulating the Expected Value (EV) function curvature; ii) outcome valence, which changes the tendency for risk seeking/aversive behaviour in cognitive decision making. In three experiments, participants set the size of a catcher in order to catch a dot moving on a random walk (with varying levels of predictability) after it emerged from behind an occluder. Catching and missing the dot were associated with scoring a variable number of outcome points depending on catcher size. In experiment 1 outcomes were most discriminable (high EV curvature) and catcher size settings were near-optimal. In experiments 2 and 3 outcomes were harder to discriminate (low EV curvature) and there was a significant bias to set the catcher size too small. Unlike cognitive decision making, the valence manipulation had little effect. Subsequent analyses suggest observed biases might reflect participants moving settings towards the region with highest EV curvature, where feedback is most informative. These data suggest that: i) unlike cognitive decisions, in this task choices are largely insensitive to outcome valence; ii) EV curvature is potentially an important factor when interpreting performance in such tasks; iii) Choice may be biased towards high EV curvature regions, consistent with value being placed on exploration to increase information return.

An integrated wearable microneedle array for the continuous monitoring of multiple biomarkers in interstitial fluid.

Implementations of wearable microneedle-based arrays of sensors for the monitoring of multiple biomarkers in interstitial fluid have lacked system integration and evidence of robust analytical performance. Here we report the development and testing of a fully integrated wearable array of microneedles for the wireless and continuous real-time sensing of two metabolites (lactate and glucose, or alcohol and glucose) in the interstitial fluid of volunteers performing common daily activities. The device works with a custom smartphone app for data capture and visualization, comprises reusable electronics and a disposable microneedle array, and is optimized for system integration, cost-effective fabrication via advanced micromachining, easier assembly, biocompatibility, pain-free skin penetration and enhanced sensitivity. Single-analyte and dual-analyte measurements correlated well with the corresponding gold-standard measurements in blood or breath. Further validation of the technology in large populations with concurrent validation of sensor readouts through centralized laboratory tests should determine the robustness and utility of real-time simultaneous monitoring of several biomarkers in interstitial fluid.

The effect of eccentricity on the linear-radial speed bias: Testing the motion-in-depth model.

Radial motion is perceived as faster than linear motion when local spatiotemporal properties are matched. This radial speed bias (RSB) is thought to occur because radial motion is partly interpreted as motion-in-depth. Geometry dictates that a fixed amount of radial expansion at increasing eccentricities is consistent with smaller motion in depth, so it is perhaps surprising that the impact of eccentricity on RSB has not been examined. With this issue in mind, across 3 experiments we investigated the RSB as a function of eccentricity. In a 2IFC task, participants judged which of a linear (test - variable speed) or radial (reference - 2 or 4°/s) stimulus appeared to move faster. Linear and radial stimuli comprised 4 Gabor patches arranged left, right, above and below fixation at varying eccentricities (3.5°-14°). For linear stimuli, Gabors all drifted left or right, whereas for radial stimuli Gabors drifted towards or away from the centre. The RSB (difference in perceived speeds between matched linear and radial stimuli) was recovered from fitted psychometric functions. Across all 3 experiments we found that the RSB decreased with eccentricity but this tendency was less marked beyond 7° - i.e. at odds with the geometry, the effect did not continue to decrease as a function of eccentricity. This was true irrespective of whether stimuli were fixed in size (Experiment 1) or varied in size to account for changes in spatial scale across the retina (Experiment 2). It was also true when we removed conflicting stereo cues via monocular viewing (Experiment 3). To further investigate our data, we extended a previous model of speed perception, which suggests perceived motion for such stimuli reflects a balance between two opposing perceptual interpretations, one for motion in depth and the other for object deformation. We propose, in the context of this model, that our data are consistent with placing greater weight on the motion in depth interpretation with increasing eccentricity and this is why the RSB does not continue to reduce in line with purely geometric constraints.

Collinear facilitation and contour integration in autistic adults: Examining lateral and feedback connectivity.

Alongside difficulties with communication and social interaction, autism is often accompanied by unusual sensory and perceptual experiences including enhanced visual performance on tasks that involve separating local parts from global context. This superiority may be the result of atypical integrative processing, involving feedback and lateral connections between visual neurons. The current study investigated the integrity of these connections in autistic adults by examining two psychophysics tasks that rely on these processes - collinear facilitation and contour integration. The relative contribution of feedback and lateral connectivity was studied by altering the timing of the target relative to the flankers in the collinear facilitation task, in 16 autistic and 16 non-autistic adults. There were no significant differences in facilitation between the autistic and non-autistic groups, indicating that for this task and participant sample, lateral and feedback connectivity appear relatively intact in autistic individuals. Contour integration was examined in a different group of 20 autistic and 18 non-autistic individuals, for open and closed contours to assess the closure effect (improved detection of closed compared to open contours). Autistic individuals showed a reduced closure effect at both short (150 ms) and longer (500 ms) stimulus presentation durations that was driven by better performance of the autistic group for the open contours. These results suggest that reduced closure in a simple contour detection paradigm is unlikely to be due to slower global processing. Reduced closure has implications for understanding sensory overload by contributing to reduced figure-ground segregation of salient visual features.

Detection of scene-relative object movement and optic flow parsing across the adult lifespan.

Moving around safely relies critically on our ability to detect object movement. This is made difficult because retinal motion can arise from object movement or our own movement. Here we investigate ability to detect scene-relative object movement using a neural mechanism called optic flow parsing. This mechanism acts to subtract retinal motion caused by self-movement. Because older observers exhibit marked changes in visual motion processing, we consider performance across a broad age range (N = 30, range: 20-76 years). In Experiment 1 we measured thresholds for reliably discriminating the scene-relative movement direction of a probe presented among three-dimensional objects moving onscreen to simulate observer movement. Performance in this task did not correlate with age, suggesting that ability to detect scene-relative object movement from retinal information is preserved in ageing. In Experiment 2 we investigated changes in the underlying optic flow parsing mechanism that supports this ability, using a well-established task that measures the magnitude of globally subtracted optic flow. We found strong evidence for a positive correlation between age and global flow subtraction. These data suggest that the ability to identify object movement during self-movement from visual information is preserved in ageing, but that there are changes in the flow parsing mechanism that underpins this ability. We suggest that these changes reflect compensatory processing required to counteract other impairments in the ageing visual system.

High-Throughput Manufacture of 3D Fiber Scaffolds for Regenerative Medicine.

Engineered scaffolds used to regenerate mammalian tissues should recapitulate the underlying fibrous architecture of native tissue to achieve comparable function. Current fibrous scaffold fabrication processes, such as electrospinning and three-dimensional (3D) printing, possess application-specific advantages, but they are limited either by achievable fiber sizes and pore resolution, processing efficiency, or architectural control in three dimensions. As such, a gap exists in efficiently producing clinically relevant, anatomically sized scaffolds comprising fibers in the 1-100 µm range that are highly organized. This study introduces a new high-throughput, additive fibrous scaffold fabrication process, designated in this study as 3D melt blowing (3DMB). The 3DMB system described in this study is modified from larger nonwovens manufacturing machinery to accommodate the lower volume, high-cost polymers used for tissue engineering and implantable biomedical devices and has a fiber collection component that uses adaptable robotics to create scaffolds with predetermined geometries. The fundamental process principles, system design, and key parameters are described, and two examples of the capabilities to create scaffolds for biomedical engineering applications are demonstrated. Impact statement Three-dimensional melt blowing (3DMB) is a new, high-throughput, additive manufacturing process to produce scaffolds composed of highly organized fibers in the anatomically relevant 1-100 µm range. Unlike conventional melt-blowing systems, the 3DMB process is configured for efficient use with the relatively expensive polymers necessary for biomedical applications, decreasing the required amounts of material for processing while achieving high throughputs compared with 3D printing or electrospinning. The 3DMB is demonstrated to make scaffolds composed of multiple fiber materials and organized into complex shapes, including those typical of human body parts.

Bacterial dominance is due to effective utilisation of secondary metabolites produced by competitors.

Interactions between bacteria govern the progression of respiratory infections; however, the mechanisms underpinning these interactions are still unclear. Understanding how a bacterial species comes to dominate infectious communities associated with respiratory infections has direct relevance to treatment. In this study, Burkholderia, Pseudomonas, and Staphylococcus species were isolated from the sputum of an individual with Cystic Fibrosis and assembled in a fully factorial design to create simple microcosms. Measurements of growth and habitat modification were recorded over time, the later using proton Nuclear Magnetic Resonance spectra. The results showed interactions between the bacteria became increasingly neutral over time. Concurrently, the bacteria significantly altered their ability to modify the environment, with Pseudomonas able to utilise secondary metabolites produced by the other two isolates, whereas the reverse was not observed. This study indicates the importance of including data about the habitat modification of a community, to better elucidate the mechanisms of bacterial interactions.

Primary Placement of a Low-Profile Gastrostomy Button Is Safe and Associated With Improved Outcomes in Children.

BACKGROUND: This study evaluates tube-specific outcomes after primary placement of low-profile buttons (LPBs) compared with long gastrostomy tubes (LGTs). MATERIALS AND METHODS: All surgically placed gastrostomy tubes from 2015 to 2017 from a single institution were reviewed. Primary outcomes were tube dislodgement and tube-related readmissions within 30 d. Secondary outcomes were resource utilization and minor complications within 6 mo. RESULTS: 53% (n = 253) of patients received an LGT and 47% (n = 228) received an LPB. Groups were similar with regard to operative indication and approach, but LPB patients were slightly older (9 versus 6 mo, P = 0.02). Tube dislodgement occurred overall in 6% of patients, with 23% and 41% experiencing leakage and granulation tissue, respectively. LGT patients experienced higher rates of tube dislodgement (9% versus 3%, P = 0.006), but no difference in tube-related readmissions (P = 0.38). LGT patients were also more likely to visit the ER for a tube-related concern (43.9% versus 31.6%, P = 0.01) and report problems of leakage around the tube (27.7% versus 17.5%, P = 0.01). No difference was found for issues of peristomal granulation tissue or in tube-related readmissions. CONCLUSIONS: Primary placement of low-profile gastrostomy buttons is safe and demonstrated superior tube-related outcomes compared with LGTs.

Mechanical properties of tissue formed in vivo are affected by 3D-bioplotted scaffold microarchitecture and correlate with ECM collagen fiber alignment.

Purpose: Musculoskeletal soft tissues possess highly aligned extracellular collagenous networks that provide structure and strength. Such an organization dictates tissue-specific mechanical properties but can be difficult to replicate by engineered biological substitutes. Nanofibrous electrospun scaffolds have demonstrated the ability to control cell-secreted collagen alignment, but concerns exist regarding their scalability for larger and anatomically relevant applications. Additive manufacturing processes, such as melt extrusion-based 3D-Bioplotting, allow fabrication of structurally relevant scaffolds featuring highly controllable porous microarchitectures.Materials and Methods: In this study, we investigate the effects of 3D-bioplotted scaffold design on the compressive elastic modulus of neotissue formed in vivo in a subcutaneous rat model and its correlation with the alignment of ECM collagen fibers. Polycaprolactone scaffolds featuring either 100 or 400 µm interstrand spacing were implanted for 4 or 12 weeks, harvested, cryosectioned, and characterized using atomic-force-microscopy-based force mapping.Results: The compressive elastic modulus of the neotissue formed within the 100 µm design was significantly higher at 4 weeks (p < 0.05), but no differences were observed at 12 weeks. In general, the tissue stiffness was within the same order of magnitude and range of values measured in native musculoskeletal soft tissues including the porcine meniscus and anterior cruciate ligament. Finally, a significant positive correlation was noted between tissue stiffness and the degree of ECM collagen fiber alignment (p < 0.05) resulting from contact guidance provided by scaffold strands.Conclusion: These findings demonstrate the significant effects of 3D-bioplotted scaffold microarchitectures in the organization and sub-tissue-level mechanical properties of ECM in vivo.

Parametric control of fiber morphology and tensile mechanics in scaffolds with high aspect ratio geometry produced via melt electrowriting for musculoskeletal soft tissue engineering.

Melt electrowriting (MEW) is an additive manufacturing technique that has the potential to create fibrous scaffolds that reproduce the scale and organization of collagen fiber networks in musculoskeletal soft tissues. For musculoskeletal soft tissue engineering, it is useful for scaffolds to have a high aspect ratio (length to width ratio of 5:1 or higher). However, the relationship between MEW process variables and the structural and mechanical properties of such scaffolds is not well understood. In addition, prior studies have cut samples from larger MEW structures, resulting in test specimens with discontinuous fibers. In this study, MEW scaffolds with low (square, 12 mm × 12 mm) and high aspect ratio (rectangular, 35 mm × 5 mm) macroscale geometries were fabricated at varying stage translation speeds or melt extrusion temperatures. Fiber morphology in both geometries and mechanical properties of the continuous rectangular structures were then quantified. Fiber diameter in both square and rectangular scaffolds generally decreased with increasing stage speed, but increased with melt temperature, though the effect of the latter was greater in square scaffolds. Interfiber spacing in both geometries was closer to the intended value as stage speed increased. Spacing became less accurate in square scaffolds with increasing melt temperature but changed little in rectangular scaffolds. Transverse fiber angle in rectangular scaffolds improved with increasing stage speed and had a median value within 1.4% of the intended angle at all temperatures. Finally, apparent tensile modulus in rectangular scaffolds decreased with increasing speed and temperature. These findings highlight the need to tailor MEW process parameters in scaffolds with high aspect ratio geometry in order to consistently generate specific structural and mechanical properties. Because of the potential to reproduce the structural anisotropy, fiber size, and mechanical properties of collagenous extracellular matrix, MEW structures are promising as musculoskeletal soft tissue scaffolds.