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Essential tremor (ET) is a movement disorder characterized primarily by action tremor which affects the regulation of movements. Disruptions in cerebello-thalamocortical networks could interfere with cognitive control over actions in ET, for example, the ability to suppress a strong automatic impulse over a more appropriate action (conflict control). The current study investigated whether ET impacts conflict control proficiency. Forty-one ET patients and 29 age-matched healthy controls (HCs) performed a conflict control task (Simon task). Participants were instructed to give a left or right response to a spatially lateralized arrow (direction of the arrow). When the action signaled by the spatial location and direction of the arrow were non-corresponding (induced conflict), the inappropriate action impulse required suppression. Overall, ET patients responded slower and less accurately compared to HCs. ET patients were especially less accurate on non-corresponding conflict (Nc) versus corresponding (Cs) trials. A focused analysis on fast impulsive response rates (based on the accuracy rate at the fastest reaction times on Nc trials) showed that ET patients made more fast errors compared to HCs. Results suggest impaired conflict control in ET compared to HCs. The increased impulsive errors seen in the ET population may be a symptom of deficiencies in the cerebello-thalamocortical networks, or, be caused by indirect effects on the cortico-striatal pathways. Future studies into the functional networks impacted by ET (cortico-striatal and cerebello-thalamocortical pathways) could advance our understanding of inhibitory control in general and the cognitive deficits in ET.

OBJECTIVE Stereotactic radiosurgery (SRS) treats severe, medically refractory essential tremor and tremor-dominant Parkinson disease. However, the optimal target for SRS treatment within the thalamic ventral intermediate nucleus (VIM) is not clearly defined. This work evaluates the precision of the physician-selected VIM target, and determines the optimal SRS target within the VIM by correlation between early responders and nonresponders. METHODS Early responders and nonresponders were assessed retrospectively by Elements Basal Ganglia Atlas autocontouring of the VIM on the pre–SRS-treatment 1-mm slice thickness T1-weighted MRI and correlating the center of the post–SRS-treatment lesion. Using pre- and posttreatment diffusion tensor imaging, the fiber tracking package in the Elements software generated tremor-related tracts from autosegmented motor cortex, thalamus, red nucleus, and dentate nucleus. Autocontouring of the VIM was successful for all patients. RESULTS Among 23 patients, physician-directed SRS targets had a medial–lateral target range from +2.5 mm to −2.0 mm from the VIM center. Relative to the VIM center, the SRS isocenter target was 0.7–0.9 mm lateral for 6 early responders and 0.9–1.1 mm medial for 4 nonresponders (p = 0.019), and without differences in the other dimensions: 0.2 mm posterior and 0.6 mm superior. Dose–volume histogram analyses for the VIM had no significant differences between responders and nonresponders between 20 Gy and 140 Gy, mean or maximum dose, and dose to small volumes. Tractography data was obtained for 4 patients. CONCLUSIONS For tremor control in early responders, the Elements Basal Ganglia Atlas autocontour for the VIM provides the optimal SRS target location that is 0.7–0.9 mm lateral to the VIM center.

Background: This study assessed associations between antenatal physical activity and the onset of spontaneous labor (SL). Methods: Data were taken from 541 participants in the third pregnancy, infection, and nutrition study who had no contraindications to antenatal physical activity. An interviewer-administered questionnaire assessed labor triggers, gestational age at birth, and physical activity within the week (24 h to 7 d) and the 24-hour period (0–24 h) prior to SL. A case-crossover design examined the association between physical activity (recreational, occupational, or any) and the risk of onset of SL within the subsequent 24 hours. Results: Overall, 21% (any), 26% (recreational), and 14% (occupational) of participants reported physical activity during the week; whereas 5% (any), 7% (recreational), and 3% (occupational) reported physical activity during the 24-hour period, prior to SL onset. Participants who reported any or occupational physical activity during the 24-hour period had a decreased likelihood of SL within the subsequent 24 hours, while participants who reported at least 30 minutes of recreational physical activity had an increased likelihood. Results remained consistent among early, full, or postterm participants. Conclusion: Recreational, but not occupational, physical activity at term may increase the likelihood of SL; however, the authors cannot rule out reverse causality.

Deep brain stimulation (DBS) is an effective treatment to improve motor symptoms in Parkinson's disease (PD). The Globus Pallidus (GPi) and the Subthalamic Nucleus (STN) are the most targeted brain regions for stimulation and produce similar improvements in PD motor symptoms. However, our understanding of stimulation effects across targets on inhibitory action control processes is limited. We compared the effects of STN (n = 20) and GPi (n = 13) DBS on inhibitory control in PD patients.We recruited PD patients undergoing DBS at the Vanderbilt Movement Disorders Clinic and measured their performance on an inhibitory action control task (Simon task) before surgery (optimally treated medication state) and after surgery in their optimally treated state (medication plus their DBS device turned on).DBS to both STN and GPi targets induced an increase in fast impulsive errors while simultaneously producing more proficient reactive suppression of interference from action impulses.Stimulation in GPi produced similar effects as STN DBS, indicating that stimulation to either target increases the initial susceptibility to act on strong action impulses while concomitantly improving the ability to suppress ongoing interference from activated impulses.Action impulse control processes are similarly impacted by stimulating dissociable nodes in frontal-basal ganglia circuitry.

The rapid expansion of entrustable professional activity (EPA) assessment programs has led to calls to ensure fidelity in implementation and integrity in meeting the goals of competency-based medical education. Initiated in July 2017, in advance of the articulated core components of EPA implementation, this article describes the structure and outcomes of the University of Virginia (UVA) EPA Program and provides support for the identified essential components.The UVA EPA Program includes workplace assessments by residents/fellows, attending faculty, and master assessors (MAs), experienced clinicians who assess students across disciplines and clinical settings. All assessors participate in formal professional development and provide verbal and written comments to support their supervision ratings. The Entrustment Committee, composed of 12 MAs, uses a shared mental model and aggregates all assessor data to make a high-stakes summative entrustment decision about students' readiness to assume the role of an acting intern.Since 2017, over 2,000 assessors have completed 56,969 EPA assessments for 1,479 students. Ninety-four percent of assessments have been done during the clerkship phase. Residents/fellows have completed a mean of 18 assessments, attending faculty a mean of 27, and MAs a mean of 882. Seventy-four percent of observed encounters involved patients with acute concerns with or without a co-morbid condition. Fifty percent of assessments occurred in inpatient and 32% in ambulatory settings. Eighty-seven percent of assessments contained narrative comments with more than 100 characters.Planned next steps will include earlier identification of students who require individualized learning to promote the development of skills related to EPAs, expansion of the remediation program to enable more students to engage in a clinical performance mastery elective, and creation of targeted professional development for assessors to reinforce the tenets of the EPA program.

There is an ever-growing body of science education research considering factors associated with teaching and learning in urban, suburban, and rural learning environments. However, there also appears to be a tendency to employ these contexts in euphemistic descriptions, when comparing of subsets of our society here in the USA. With this in mind, we attempted to determine the ways the terms urban, suburban, and rural, are used, defined, and characterized in science education research. This process included two developmental phases, which resulted in the development of our multi-dimensional analytical framework; a trial phase to test the framework; and finally an analytical phase in which we used this framework to examine a decade of science education research. The framework was constructed using emergent themes identified in education and government publications during the first two phases. It proved useful to assess whether urban, suburban, and rural were being explicitly, implicitly, or undefined in science education research. Results suggest scant evidence of the explicit defining/characterization of “urban,” “suburban,” and “rural.” This supported our suspicion that they are frequently being employed in the implication of subsets of our population, or as non-descript adjectives. Selected articles (n = 122) yielded (n = 28) explicit, (n = 60) implicit, and (n = 34) non-definitions of the terms. Such practices may have consequences with respect to educational policy and social justice concerns in science education. This is of particular interest with respect to the normalization of certain settings, cultures, behaviors, and students in science education.

Persons identified in early childhood as having autism spectrum disorder (autism) often have co-occurring health problems that extend into adolescence (1-3). Although only limited data exist on their health and use of health care services as they transition to adolescence, emerging data suggest that a minority of these persons receive recommended guidance* from their primary care providers (PCPs) starting at age 12 years to ensure a planned transition from pediatric to adult health care (4,5). To address this gap in data, researchers analyzed preliminary data from a follow-up survey of parents and guardians of adolescents aged 12-16 years who previously participated in the Study to Explore Early Development (https://www.cdc.gov/ncbddd/autism/seed.html). The adolescents were originally studied at ages 2-5 years and identified at that age as having autism (autism group) or as general population controls (control group). Adjusted prevalence ratios (aPRs) that accounted for differences in demographic characteristics were used to compare outcomes between groups. Adolescents in the autism group were more likely than were those in the control group to have physical difficulties (21.2% versus 1.6%; aPR = 11.6; 95% confidence interval [CI] = 4.2-31.9), and to have additional mental health or other conditions† (one or more condition: 63.0% versus 28.9%; aPR = 1.9; 95% CI = 1.5-2.5). Adolescents in the autism group were more likely to receive mental health services (41.8% versus 22.1%; aPR = 1.8, 95% CI = 1.3-2.6) but were also more likely to have an unmet medical or mental health service need§ (11.0% versus 3.2%; aPR = 3.1; 95% CI = 1.1-8.8). In both groups, a small percentage of adolescents (autism, 7.5%; control, 14.1%) received recommended health care transition (transition) guidance. These findings are consistent with previous research (4,5) indicating that few adolescents receive the recommended transition guidance and suggest that adolescents identified with autism in early childhood are more likely than adolescents in the general population to have unmet health care service needs. Improved provider training on the heath care needs of adolescents with autism and coordination of comprehensive programs¶ to meet their needs can improve delivery of services and adherence to recommended guidance for transitioning from pediatric to adult health care.

Objective Deep brain stimulation (DBS) improves motor symptoms in Parkinson’s disease (PD), but it can also disrupt verbal fluency with significant costs to quality of life. The current study investigated how variability of bilateral active electrode coordinates along the superior/inferior, anterior/posterior, and lateral/medial axes in the subthalamic nucleus (STN) or the globus pallidus interna (GPi) contribute to changes in verbal fluency. We predicted that electrode location in the left hemisphere would be linked to changes in fluency, especially in the STN. Methods Forty PD participants treated with bilateral DBS targeting STN (n = 23) or GPi (n = 17) completed verbal fluency testing in their optimally treated state before and after DBS therapy. Normalized atlas coordinates from left and right active electrode positions along superior/inferior, anterior/posterior, and lateral/medial axes were used to predict changes in fluency postoperatively, separately for patients with STN and GPi targets. Results Consistent with prior studies, fluency significantly declined pre‐ to postsurgery (in both DBS targets). In STN‐DBS patients, electrode position along the inferior to superior axis in the left STN was a significant predictor of fluency changes; relatively more superior left active electrode was associated with the largest fluency declines in STN. Electrode coordinates in right STN or GPi (left or right) did not predict fluency changes. Interpretation We discuss these findings in light of putative mechanisms and potential clinical impact.

Prior studies investigating restricted and repetitive behavior (RRB) subtypes within autism spectrum disorder (ASD) have found varied factor structures for symptom groupings, in part, due to variation in symptom measurement and broad sample age ranges. This study examined RRBs among 827 preschool-age children, ages 35 to 71 months, through an exploratory factor analysis of RRB items from the Autism Diagnostic Interview-Revised (ADI-R) collected through the Study to Explore Early Development. The factor structures of RRBs among children with confirmed ASD versus those with non-autism developmental concerns were qualitatively compared. Correlations between RRB factors and participant characteristics were examined in the ASD group. Three conceptually well-defined factors characterized as repetitive sensorimotor behaviors (RSMB), insistence on sameness (IS), and a novel stereotyped speech (SPEECH) factor emerged for the ASD group only. Distinct factors were supported by different clinical correlates. Findings have implications for improving differential diagnosis and understanding of ASD symptomatology in this age range.

Whole-lung irradiation is typically used in pediatric patients to decrease the risk of future lung metastases, but radiation dose to normal tissue is associated with long-term risks. Proton whole-lung irradiation (PWLI) provides an opportunity to decrease radiation dose to normal tissue and potentially decrease late toxicity.This retrospective study included patients treated with spot-scanning PWLI at a single institution. Toxicity and oncologic outcomes were reviewed. Intensity modulated radiation therapy (IMRT) plans were created prospectively or retrospectively for dosimetric comparisons. Simple paired t tests were performed to assess differences between IMRT and PWLI dosimetric parameters.Twelve patients treated with PWLI were included in this study. Median age was 15 years (range, 3-34). Most (75%) had Ewing sarcoma. Most (92%) received 15 Gy in 10 fractions PWLI, and 3 (25%) received a focal pulmonary boost. Median follow-up was 16.5 months (range, 0-40.4 months). At last follow-up, 1 patient died of disease, while 11 were still alive (7 without disease, 4 with ongoing disease). During and immediately after treatment, 5 patients developed fatigue, 2 patients developed cough, and 1 patient developed nausea. Each treatment-related adverse event was Common Terminology Criteria for Adverse Events (version 5.0) grade 1 and resolved within 3 weeks of treatment completion. No patients have experienced clinical or radiographic pneumonitis or evidence of clinically apparent cardiac toxicity. Compared with IMRT plans, PWLI decreased mean dose to the heart, coronary artery, cardiac valve, left ventricle, aorta, breast, esophagus, kidney, liver, pancreas, thyroid, stomach, and spleen (all P.001), without sacrificing target coverage.PWLI is feasible to deliver, decreases dose to normal tissue compared with IMRT, and appears to be well-tolerated. PWLI provides potential for decreased late toxicity and merits further investigation.

We propose designs of silicon nitride (Si3N4) waveguides with enhanced nonlinear parameter and engineered anomalous group velocity dispersion (GVD) by addition of tellurium oxide (TeO2) top-coating layers of various thicknesses. The proposed waveguides have calculated nonlinear parameters of up to three times that of stoichiometric Si3N4 and exhibit anomalous GVD at near infrared wavelengths. The GVD of such waveguides can be tuned between the normal and anomalous regime with different zero dispersion wavelengths by adjusting the thickness of TeO2 coating. These designs offer promise of higher performance nonlinear devices on a standard low-loss Si3N4 platform with the possibility of integration of active functionalities owing to higher solubility of rare earth dopants in tellurium oxide.

We show experimental results on large mode area waveguides in silicon photonics. Mode area up to 30 μm2 is demonstrated in a 10 cm long serpentine waveguide with 0.75 dB/cm propagation loss limited only by the aluminum oxide film loss.

We demonstrate subwavelength grating metamaterial ring resonators on a silicon nitride platform. We report an internal Q factor of 2.11˖105 and 1.48 dB/cm propagation loss at 1540 nm wavelength. We discuss the potential of these novel devices for applications in evanescent field sensing and light amplification.

We present low-threshold lasing around 1.9 µm in compact thulium-silicon hybrid microdisk resonators with a pulley-coupled design. We observe total on-chip output powers of > 2 mW and threshold pump powers of < 1 mW.

We report on octave-spanning supercontinuum generation in a 400-nm-thick silicon nitride waveguide coated with tellurite glass. An octave-spanning supercontinuum is achieved at a low peak power of 482 W using a 100-fs laser centered at 1565 nm.

We report on silicon waveguide distributed Bragg reflector (DBR) cavities hybridized with a tellurium dioxide (TeO2) cladding and coated in plasma functionalized poly (methyl methacrylate) (PMMA) for label free biological sensors. We describe the device structure and fabrication steps, including reactive sputtering of TeO2 and spin coating and plasma functionalization of PMMA on foundry processed Si chips, as well as the characterization of two DBR designs via thermal, water, and bovine serum albumin (BSA) protein sensing. Plasma treatment on the PMMA films was shown to decrease the water droplet contact angle from ∼70 to ∼35°, increasing hydrophilicity for liquid sensing, while adding functional groups on the surface of the sensors intended to assist with immobilization of BSA molecules. Thermal, water and protein sensing were demonstrated on two DBR designs, including waveguide-connected sidewall (SW) and waveguide-adjacent multi-piece (MP) gratings. Limits of detection of 60 and 300 × 10−4 RIU were measured via water sensing, and thermal sensitivities of 0.11 and 0.13 nm/°C were measured from 25–50 °C for SW and MP DBR cavities, respectively. Plasma treatment was shown to enable protein immobilization and sensing of BSA molecules at a concentration of 2 µg/mL diluted in phosphate buffered saline, demonstrating a ∼1.6 nm resonance shift and subsequent full recovery to baseline after stripping the proteins with sodium dodecyl sulfate for a MP DBR device. These results are a promising step towards active and laser-based sensors using rare-earth-doped TeO2 in silicon photonic circuits, which can be subsequently coated in PMMA and functionalized via plasma treatment for label free biological sensing.