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.

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.

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.

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.

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.

The Primary Role of Flow Processing in the Identification of Scene-Relative Object Movement.

Retinal image motion could be due to the movement of the observer through space or an object relative to the scene. Optic flow, form, and change of position cues all provide information that could be used to separate out retinal motion due to object movement from retinal motion due to observer movement. In Experiment 1, we used a minimal display to examine the contribution of optic flow and form cues. Human participants indicated the direction of movement of a probe object presented against a background of radially moving pairs of dots. By independently controlling the orientation of each dot pair, we were able to put flow cues to self-movement direction (the point from which all the motion radiated) and form cues to self-movement direction (the point toward which all the dot pairs were oriented) in conflict. We found that only flow cues influenced perceived probe movement. In Experiment 2, we switched to a rich stereo display composed of 3D objects to examine the contribution of flow and position cues. We moved the scene objects to simulate a lateral translation and counter-rotation of gaze. By changing the polarity of the scene objects (from light to dark and vice versa) between frames, we placed flow cues to self-movement direction in opposition to change of position cues. We found that again flow cues dominated the perceived probe movement relative to the scene. Together, these experiments indicate the neural network that processes optic flow has a primary role in the identification of scene-relative object movement.SIGNIFICANCE STATEMENT Motion of an object in the retinal image indicates relative movement between the observer and the object, but it does not indicate its cause: movement of an object in the scene; movement of the observer; or both. To isolate retinal motion due to movement of a scene object, the brain must parse out the retinal motion due to movement of the eye ("flow parsing"). Optic flow, form, and position cues all have potential roles in this process. We pitted the cues against each other and assessed their influence. We found that flow parsing relies on optic flow alone. These results indicate the primary role of the neural network that processes optic flow in the identification of scene-relative object movement.

Enzymatic/Immunoassay Dual-Biomarker Sensing Chip: Towards Decentralized Insulin/Glucose Detection.

Performing bioassay formats based on enzyme and antibody recognition reactions with a single detection chip remains an unmet challenge owing to the different requirements of such bioassays. Herein, we describe a dual-marker biosensor chip, integrating enzyme and antibody-based assays for simultaneous electrochemical measurements of insulin (I) and glucose (G). Simultaneous G/I sensing has been realized by addressing key fabrication and operational challenges associated with the different assay requirements and surface chemistry. The I immunosensor relies on a peroxidase-labeled sandwich immunoassay, while G is monitored through reaction with glucose oxidase. The dual diabetes biomarker chip offers selective and reproducible detection of picomolar I and millimolar G concentrations in a single microliter sample droplet within less than 30 min, including direct measurements in whole blood and saliva samples. The resulting integrated enzymatic-immunoassay biosensor chip opens a new realm in point-of-care multiplexed biomarker detection.

Engineering 3D-Bioplotted scaffolds to induce aligned extracellular matrix deposition for musculoskeletal soft tissue replacement.

PURPOSE: Tissue engineering and regenerative medicine approaches have the potential to overcome the challenges associated with current treatment strategies for meniscus injuries. 3D-Bioplotted scaffolds are promising, but have not demonstrated the ability to guide the formation of aligned collagenous matrix in vivo, which is critical for generating functional meniscus tissue. In this study, we evaluate the ability of 3D-Bioplotted scaffold designs with varying interstrand spacing to induce the deposition of aligned matrix in vivo. MATERIALS AND METHODS: 3D-Bioplotted polycaprolactone scaffolds with 100, 200, or 400 µm interstrand spacing were implanted subcutaneously in a rat model for 4, 8, or 12 weeks. Scaffolds were harvested, paraffin-embedded, sectioned, and stained to visualize cell nuclei and collagen. Quantitative image analysis was used to evaluate cell density, matrix fill, and collagen fiber alignment within the scaffolds. RESULTS: By 4 weeks, cells had infiltrated the innermost scaffold regions. Similarly, collagenous matrix filled interstrand regions nearly completely by 4 weeks. By 12 weeks, aligned collagen was present in all scaffolds. Generally, alignment along the scaffold strands increased over time for all three interstrand spacing groups. Distribution of collagen fiber alignment angles narrowed as interstrand spacing decreased. CONCLUSIONS: 3D-Bioplotted scaffolds allow for complete cell infiltration and collagenous matrix production throughout the scaffold. The ability to use interstrand spacing as a means of controlling the formation of aligned collagen in vivo was demonstrated, which helps establish a design space for scaffold-based meniscus tissue engineering.

Perceptuo-motor, cognitive, and description-based decision-making seem equally good.

Classical studies suggest that high-level cognitive decisions (e.g., choosing between financial options) are suboptimal. In contrast, low-level decisions (e.g., choosing where to put your feet on a rocky ridge) appear near-optimal: the perception-cognition gap. Moreover, in classical tasks, people appear to put too much weight on unlikely events. In contrast, when people can learn through experience, they appear to put too little weight on unlikely events: the description-experience gap. We eliminated confounding factors and, contrary to what is commonly believed, found results suggesting that (i) the perception-cognition gap is illusory and due to differences in the way performance is assessed; (ii) the description-experience gap arises from the assumption that objective probabilities match subjective ones; (iii) people's ability to make decisions is better than the classical literature suggests; and (iv) differences between decision-makers are more important for predicting peoples' choices than differences between choice tasks.

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.

Evaluation of the Fluids Mixing Enclosure System for Life Science Experiments During a Commercial Caenorhabditis elegans Spaceflight Experiment.

The Student Spaceflight Experiments Program (SSEP) is a United States national science, technology, engineering, and mathematics initiative that aims to increase student interest in science by offering opportunities to perform spaceflight experiments. The experiment detailed here was selected and flown aboard the third SSEP mission and the first SSEP mission to the International Space Station (ISS). Caenorhabditis elegans is a small, transparent, self-fertilizing hermaphroditic roundworm that is commonly used in biological experiments both on Earth and in Low Earth Orbit. Past experiments have found decreased expression of mRNA for several genes whose expression can be controlled by the FOXO transcription factor DAF-16. We flew a daf-16 mutant and control worms to determine if the effects of spaceflight on C. elegans are mediated by DAF-16. The experiment used a Type Two Fluids Mixing Enclosure (FME), developed by Nanoracks LLC, and was delivered to the ISS aboard the SpaceX Dragon and returned aboard the Russian Soyuz. The short time interval between experiment selection and the flight rendered preflight experiment verification tests impossible. In addition, published research regarding the viability of the FME in life science experiments was not available. The experiment was therefore structured in such a way as to gather the needed data. Here we report that C. elegans can survive relatively short storage and activation in the FME but cannot produce viable populations for post-flight analysis on extended missions. The FME appears to support short-duration life science experiments, potentially on supply or crew exchange missions, but not on longer ISS expeditions. Additionally, the flown FME was not properly activated, reportedly due to a flaw in training procedures. We suggest that a modified transparent FME could prevent similar failures in future flight experiments.

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.

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 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.

Visual extrapolation under risk: human observers estimate and compensate for exogenous uncertainty.

Humans commonly face choices between multiple options with uncertain outcomes. Such situations occur in many contexts, from purely financial decisions (which shares should I buy?) to perceptuo-motor decisions between different actions (where should I aim my shot at goal?). Regardless of context, successful decision-making requires that the uncertainty at the heart of the decision-making problem is taken into account. Here, we ask whether humans can recover an estimate of exogenous uncertainty and then use it to make good decisions. Observers viewed a small dot that moved erratically until it disappeared behind an occluder. We varied the size of the occluder and the unpredictability of the dot's path. The observer attempted to capture the dot as it emerged from behind the occluded region by setting the location and extent of a 'catcher' along the edge of the occluder. The reward for successfully catching the dot was reduced as the size of the catcher increased. We compared human performance with that of an agent maximizing expected gain and found that observers consistently selected catcher size close to this theoretical solution. These results suggest that humans are finely tuned to exogenous uncertainty information and can exploit it to guide action.

Knowing when to move on: cognitive and perceptual decisions in time.

We investigated people's ability to decide how much time to spend on the task at hand. To make such decisions well, one must take into account, among other things, the cost of failing and how one's task performance changes as a function of time. We first investigated timing decisions when the underlying task was perceptual. Decisions were highly efficient and suggested that people can make good use of perceptual knowledge and abstract reward information. Previous studies have found that perceptual decisions are generally optimal, but that cognitive decisions are generally suboptimal--a perception-cognition gap. Does a similar gap exist for timing decisions? We compared timing decisions for a perceptual task with timing decisions for more cognitive tasks. Performance was highly similar across the tasks, which suggests that knowledge can be acquired, and used to make timing decisions, in an equally efficient way regardless of whether that knowledge is derived through perceptual or cognitive experience.

Does optic flow parsing depend on prior estimation of heading?

We have recently suggested that neural flow parsing mechanisms act to subtract global optic flow consistent with observer movement to aid in detecting and assessing scene-relative object movement. Here, we examine whether flow parsing can occur independently from heading estimation. To address this question we used stimuli comprising two superimposed optic flow fields comprising limited lifetime dots (one planar and one radial). This stimulus gives rise to the so-called optic flow illusion (OFI) in which perceived heading is biased in the direction of the planar flow field. Observers were asked to report the perceived direction of motion of a probe object placed in the OFI stimulus. If flow parsing depends upon a prior estimate of heading then the perceived trajectory should reflect global subtraction of a field consistent with the heading experienced under the OFI. In Experiment 1 we tested this prediction directly, finding instead that the perceived trajectory was biased markedly in the direction opposite to that predicted under the OFI. In Experiment 2 we demonstrate that the results of Experiment 1 are consistent with a positively weighted vector sum of the effects seen when viewing the probe together with individual radial and planar flow fields. These results suggest that flow parsing is not necessarily dependent on prior estimation of heading direction. We discuss the implications of this finding for our understanding of the mechanisms of flow parsing.

A novel power toothbrush with multi-directional, triple zone cleaning technology.

PURPOSE: Numerous laboratory and clinical studies have proven that certain power toothbrush technologies are more effective in removal of dental plaque and reduction of gingivitis than regular manual toothbrushes. Regardless of this evidence, there is still a large group of individuals who prefer the experience of a manual-like toothbrush. Recently a novel multi-directional power brush has been developed as an alternative for those people who favor the traditional size and shape of a manual toothbrush and prefer the manual brushing technique, but would benefit from the greater cleaning efficiency of the power brush. METHODS: This unique multi-directional power toothbrush with triple-zone cleaning technology has been tested in multiple clinical trials. This special issue introduces the technical features of the brush and presents four clinical investigations conducted with this power toothbrush versus manual and sonic controls. RESULTS: The studies described in this issue demonstrate the superior efficacy of the multi-directional brush in plaque and gingivitis reduction relative to control brushes, even in the hard-to-reach interdental spaces and marginal areas.

Brush head wear, subject-perceived and laboratory cleaning performance of two oscillating-rotating electric toothbrush heads over 3 months.

PURPOSE: To evaluate the progression of wear and the effect of wear on subject-perceived and laboratory cleaning efficacy of two oscillating-rotating electric brush heads, Oral-B Precision Clean (PC) and a store brand Easyflex (SB) brush head, after 4, 6, 8 and 13 weeks of use. METHODS: This research consisted of three phases: (1) Subject questionnaires--A crossover, single-blinded study was conducted among healthy adults who were regular users of Oral-B oscillating-rotating electric toothbrushes. Subjects were recruited from a general population and randomized based on age and gender into one of four cohorts reflecting the time period of use for each product: 4, 6, 8 or 13 weeks. After brushing with their first product (either PC or SB) for the designated period of time, subjects completed a questionnaire evaluating the brush head on 17 attributes related to perceived cleaning performance, brush head condition (i.e., durability) and brush head feel (i.e., gentleness). Subjects then used the second test product for the same period of time and completed the same questionnaire. (2) Wear index investigation--At the end of each time period, subjects' worn brush head pairs were evaluated by an independent, blinded investigator to determine the wear index score. (3) Robot testing--To analyze the laboratory cleaning efficacy of worn refills in the laboratory, a representative sample of 12 subject brush head pairs for each of the four cohorts were evaluated (96 brush heads in total). To analyze the laboratory cleaning efficacy for PC at Week 13 with SB at Week 4, a separate set of 20 subjects (40 brush heads in total) were evaluated. A robot was used to brush standard typodonts (Frasaco A3) covered with plaque substitute with the worn brush head for 2 minutes under standardized, controlled conditions simulating human brushing behavior. A 3D laser scan system was used to measure the area still covered with plaque substitute at different dental sites. RESULTS: Subject questionnaire--267 subjects completed study questionnaires. Statistically significant superior ratings (P < 0.05) were obtained with the PC brush head compared to the SB brush head for virtually all attributes at all four time periods (16/17 attributes for Weeks 4, 6 and 8 and 17/17 at Week 13). Highly significant advantages (P < 0.0001) were seen for 'overall rating', 'overall cleaning' and 'ready to replace brush head' attributes. Wear Index-- A total of 486 brush head samples (243 pairs) were analyzed for wear. At all four time periods, PC brush heads had a statistically significantly lower (P < 0.0005) mean wear index than SB brush heads. Robot Test--136 brush heads were analyzed using a laboratory (robot) test to investigate cleaning efficacy. Directionally higher laboratory cleaning for PC versus SB was observed for all dental sites (35/35) for all time periods. Comparing PC at Week 13 with SB at Week 4 showed statistically significant differences (P < 0.05) in favor of PC for the majority of dental sites and time periods (23/35).