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Although children with incarcerated parents exhibit more behavior problems, health concerns, and academic difficulties than their peers, few interventions or resources are available to support affected children. This randomized, controlled, multisite efficacy trial evaluated Sesame Street’s "Little Children, Big Challenges: Incarceration" initiative with children aged 3 to 8 years with a jailed father. Seventy-one diverse children and their caregivers were randomized to an educational outreach group (n = 32) or wait list control group (n = 39). Researchers observed children during jail visits and interviewed caregivers by phone 2 and 4 weeks later. The effects of the intervention on children’s behavior and emotions occurring during a jail visit depended on what children had been told about the father’s incarceration. Children who were told honest, developmentally appropriate explanations showed less negative affect at entry, an increase in negative affect when the intervention was administered, and a decrease in negative affect during the visit. Intervention group children who were told distortions, nothing, or explanations that were not developmentally appropriate showed more negative affect initially, and their negative affect remained relatively stable during their time in the jail. In addition, children who were told the simple, honest truth about the parent’s incarceration (a recommendation in the educational materials) exhibited more positive affect during the visit, with a medium effect size. Caregivers in the educational outreach group reported more positive change in how they talked to children about the incarceration over time compared to the control group.

Summary To follow climate change in sediment cores it is important to now how quick a biomarker reacts to climate change. Here we investigated a sediment core from Lake Van retrieved during an ICDP campaign in 2021. We compare compound specific hydrogen isotopes measurements on biomarkers, i.e. long-chain n-alkanes and alkenones to understand which biomarker reacts first to, in this case, the water cycle (precipitation, evaporation) in the Eastern Turkey area.

Commercial silicon is prone to form silicon oxide precipitates during high-temperature treatments typical for solar cell production. Oxide precipitates can cause severe efficiency degradation in solar cells. We have developed a model describing the nucleation and growth of oxide precipitates that considers silicon self-interstitial defects and surface effects influencing the precipitate growth in ∼150 μm thick wafers during the solar cell processing. This kinetic model is calibrated with experiments that cause a well-defined and strong precipitate growth to give a prediction of the carrier lifetime limitation because of the oxide precipitates. We test the oxide precipitate model with scanning Fourier-transform infrared spectroscopy, selective etching, and lifetime measurements on typical Cz solar cell wafers before and after solar cell processes. Despite the relatively rough saw damaged etched surfaces and the thin wafers, we observe recurring ring patterns in the measurements of interstitial oxygen reductions, oxide precipitate etch pit density, and recombination activity by photoluminescence imaging. The concentration of precipitated oxygen correlates with the recombination activity and with the initial interstitial oxygen concentration. However, we found lifetime measurements to be a more sensitive technique to study oxide precipitates and using these we find smaller precipitates not detected by selective etching are very recombination active too. The measured concentrations of precipitated oxygen and lifetime agree fairly well with the predictions of the model.\ud

This chapter addresses key questions that can guide potential collaborations with individual simulation experts or groups of experts who work in simulation centers. The science of simulation provides invaluable tools that can be used to support education, safety and quality improvement efforts, and research, making partnerships ideal in many ways. Simulationists possess a broad range of expertise. Expertise in curriculum design, knowledge transfer through immersive education, adult behavioral modification, and feedback and debriefing can be used to enhance educational program development. Expertise in process improvement strategies, change management, and teamwork and teambuilding can be invaluable for quality and safety program implementation. Expertise in creating psychological safety, cognitive engineering and decision-making can assist in efforts to positively alter organizational culture. Some simulationists are also expert researchers who design and carry out research on a wide range of subjects. Typically, simulation research includes studies on team cognition, team situation awareness, human-technology interaction, expert-novice differences, educational effectiveness, and process improvement. In keeping with the focus of this book, this chapter will focus primarily on these skills as they pertain to quality and safety efforts, and much of the material will address how to leverage this expertise within existing quality and safety frameworks. We also discuss the types of simulation relationships and services that are available along with potential strategies for initial engagement. The chapter concludes with a presentation of potential funding sources that could be used to sustain the relationship long term.

The interest in cast mono silicon is increasing due to its lower energy consumption and resulting smaller carbon footprint, lower oxygen content and resulting less oxygen-related defects as well as easy scalability to large wafer formats like 210 × 210 mm2 full square. As a cast silicon alternative to high performance multicrystalline (hpm) silicon, which rapidly lost market share, we analyze the cell efficiency potential of cast mono silicon in a TOPCon cell structure. We show how the absence of grain boundaries and the exceptional tolerance of the material quality towards high temperature processing enable this significant increase of the cell efficiency potential compared to hpm silicon. The very effective suppression of crystal defects by the Seed Manipulation for ARtificially controlled defect Technique (SMART) results in a very low lateral variation of the high material quality. We present certified cell efficiencies of 23.3% on n-type material crystallized in our labs, which demonstrates the high efficiency potential even for our lab-type G2 crystallization. An additional crystallization experiment for 210 × 210 mm2 wafers demonstrates that SMART mono is compatible to large wafer sizes. A significant difference of the crystallization costs for Cz and cast mono crystallization as a function of electricity costs is discussed.

The angular and linear vestibulo-ocular reflex responses are greater when viewing near targets to compensate for the relatively larger translation of the eyes with respect to the target. Our aim was to measure vestibular evoked myogenic potentials using a lateral ocular electrode montage (oVEMP) with a laterally applied stimulus using a mini-shaker during both far- and near-viewing (vergence) distances to determine whether vergence affects the oVEMP response as it does the semicircular canal vestibulo-ocular reflex response. Our results show that during vergence, the p1 and n1-p1 amplitude of the lateral oVEMP response increases significantly, whereas the latencies do not change significantly. We suggest that the physiological basis for this vergence-mediated amplitude increase in potentials may be the same as those already documented using transient linear head accelerations. Our data also suggest that irregular vestibular afferents are likely mediating the vergence-mediated gain increase during linear head accelerations because only irregular afferents are stimulated during short, transient 500 Hz stimuli.

Suitable stretchable electronics is the key to promote future human-machine collaboration to facilitate processes in daily life. Sensors and actuators on humans will enable a close and yet unhesitating interaction with robots by translating data between biological and technical systems. This paper describes our first approach for chip integration and stretchable interconnect manufacturing in order to achieve reliable stretchable interconnects. Therefore inkjet printed silver horseshoe-interconnects with a radius of 500µm on spin coated polyurethane substrate are tested on a self-developed stretch test setup. More than 400 stretch and release cycles on 10% and 20% stretching were achieved. Furthermore, a polymer chip-embedding process by polymer casting is shown to apply fan-out redistribution layer directly on thin chip carrier. Those carriers can be integrated in stretchable foils in order to achieve miniaturized and low-profile assemblies for human-machine interfaces.

OBJECTIVE To examine the high frequency horizontal vestibular ocular-reflex (hVOR) during acute attacks of vertigo in Meniere's disease (MD). STUDY DESIGN Retrospective case series and literature review. SETTING Tertiary academic medical center. PATIENTS Patients with clinical diagnosis of unilateral "definite MD." INTERVENTION Review of medical records. MAIN OUTCOME MEASURES Spontaneous nystagmus and the dynamic hVOR gain change at different stages of an acute episode of MD attack. RESULTS We studied 10 vertigo attacks during the unique stages of the episode. During the acme stage of the attack, lower hVOR gain was recorded on the affected side (mean 0.48 ± 0.23), which was associated with a paralytic nystagmus (beating away from the affected ear). Additionally, the mean hVOR gain remained significantly (p

Background and purpose Few tools are currently available to quantify gaze stability retraining exercises. This project examined the utility of a head-worn inertial measurement unit (IMU) to quantify head movement frequency, velocity, and amplitude during gaze stability exercises. Methods Twenty-eight individuals with multiple sclerosis and complaints of dizziness or a history of falls were randomly assigned to either a strength and aerobic exercise (SAE) or gaze and postural stability (GPS) group. During a 6-week intervention, participants wore a head-mounted IMU 3 times (early, middle, and late). For aim 1, the frequency, mean peak velocity, and mean peak amplitude of head turns during equivalent duration components of group-specific exercises were compared using general linear models. For aim 2, the progression of treatment in the GPS group was examined using general linear regression models for each outcome. Results Aim 1 revealed the GPS group demonstrated significantly greater velocity and amplitude head turns during treatment than the SAE group. The frequency of head turns did not significantly differ between the 2 groups. The aim 2 analyses demonstrated that the yaw and pitch frequency of head turns significantly increased during gaze stability exercises over the 6-week intervention. Velocity and amplitude of head turns during yaw and pitch gaze stability exercises did not significantly change. Discussion and conclusions A head-worn IMU during rehabilitation distinguished between groups. Furthermore, within the GPS group, the IMU quantified the progression of the frequency of head movements during gaze stability exercises over time.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A320).

Alpha oscillations (8-13 Hz) have been shown to play an important role in dynamic neural processes underlying learning and memory. The goal of this study was to scrutinize the role of α oscillations in communication within a network implicated in motor sequence learning. To this end, we conducted two experiments using the serial reaction time task. In the first experiment, we explored changes in α power and cross-channel α coherence. We found a gradual decrease in learning-related α power over left premotor cortex (PMC), somatosensory cortex (S1) and tempo-parietal junction (TPJ). Alpha coherence between left PMC/S1 and right cerebellar crus I was reduced for sequence learning, possibly reflecting a functional decoupling in a motor-cerebellar loop during the motor learning process. In the second experiment in a different cohort, we applied 10Hz transcranial alternating current stimulation (tACS), a method shown to entrain local oscillatory activity, to left M1 (lM1) and right cerebellum (rCB) during sequence learning. We observed learning deficits during rCB tACS compared to sham, but not during lM1 tACS. In addition, learning-related α power following rCB tACS was increased in left PMC, possibly reflecting a decrease in neural activity. Importantly, learning-specific coherence between left PMC and right cerebellar lobule VIIb was enhanced following rCB tACS. These findings suggest that interactions within a premotor-cerebellar loop, which are underlying motor sequence learning, are mediated by α oscillations. We show that they can be modulated through external entrainment of cerebellar oscillations, which then modulates motor cortical α and interferes with sequence learning.

Objective Deficits in vestibular function increase the risk for falls while turning. However, the clinical assessment of turning in patients with vestibular dysfunction is lacking, and evidence is limited that identifies the effectiveness of vestibular physical therapy in improving turning performance. The purpose of this study was to quantify walking and turning performance during the instrumented Timed “Up & Go” (TUG) test using body-worn inertial measurement units (IMUs). Novel instrumented TUG parameters were investigated for ability to distinguish patients with unilateral vestibular deafferentation (UVD) from control groups and discriminate the differences in turning parameters of patients with UVD following vestibular physical therapy. Methods Thirty-eight individuals were recruited following UVD surgery: 26 age-matched veteran controls with reports of dizziness not from a peripheral vestibular origin, and 12 age-matched healthy controls. Participants were donned with IMUs and given verbal instructions to complete the TUG test as fast as safely possible. The IMU-instrumented and automated assessment of the TUG test provided component-based TUG parameters, including the novel walk:turn ratio. Among the participants with UVD, 19 completed an additional instrumented TUG testing after vestibular physical therapy. Results The walk:turn time ratio showed that turning performance in patients with UVD before rehabilitation is significantly more impaired than both the individuals with nonperipheral conditions and healthy controls. Vestibular rehabilitation significantly improved turning performance and “normalized” their walk:turn time ratio compared with healthy controls. The duration of the straight walking component in individuals with UVD before vestibular physical therapy, however, was not significantly different compared with that component in people after vestibular physical therapy and in healthy controls. Conclusion The IMU-instrumented TUG test can be used to distinguish individuals with vestibular deafferentation and to objectively quantify the change in their turning performance after vestibular physical therapy. Impact The IMU-based instrumented TUG parameters have the potential to quantify the efficacy of vestibular physical therapy and be adopted in the clinic.

One component of vestibular rehabilitation in patients with vestibulo-ocular reflex (VOR) hypofunction is gaze-stabilizing exercises that seek to increase (adapt) the VOR response. These prescribed home-based exercises are performed by the patient and thus their use/training is inherently variable. We sought to determine whether this variability affected VOR adaptation in ten healthy controls (× 2 training only) and ten patients with unilateral vestibular hypofunction (× 1 and × 2 training). During × 1 training, patients actively (self-generated, predictable) move their head sinusoidally while viewing a stationary fixation target; for × 2 training, they moved their outstretched hand anti-phase with their head rotation while attempting to view a handheld target. We defined the latter as manual × 2 training because the subject manually controls the target. In this study, head rotation frequency during training incrementally increased 0.5–2 Hz over 20 min. Active and passive (imposed, unpredictable) sinusoidal (1.3-Hz rotations) and head impulse VOR gains were measured before and after training. We show that for controls, manual × 2 training resulted in significant sinusoidal and impulse VOR adaptation of ~ 6 % and ~ 3 %, respectively, though this was ~two-thirds lower than increases after computer-controlled × 2 training (non-variable) reported in a prior study. In contrast, for patients, there was an increase in impulse but not sinusoidal VOR response after a single session of manual × 2 training. Patients had more than double the variability in VOR demand during manual × 2 training compared to controls, which could explain why adaptation was not significant in patients. Our data suggest that the clinical × 1 gaze-stabilizing exercise is a weak stimulus for VOR adaptation.

The vestibulo-ocular reflex (VOR) maintains stable vision during rapid head rotations by rotating the eyes in the opposite direction to the head. The latency between onset of the head rotation and onset of the eye rotation is 5–8 ms in healthy humans. However, VOR latency can be 3–4 times larger in patients treated with intra-tympanic gentamicin. A prior study showed that latency can be trained with head rotations at 0.2 Hz. We sought to determine how the VOR is affected when a delay between vestibular and visual stimuli is added during adaptation training with high-frequency head rotations (impulses), where the VOR is the main vision-stabilizing system. Using a variant of the incremental VOR adaptation technique, the delay between head rotation onset and movement onset of a visual target was gradually increased. With this training, the instantaneous VOR gain demand (= target/head velocity) varied from less than unity to greater than unity during each head impulse, albeit in a consistent and repeatable way. We measured the active and passive VOR gain and latency before and after VOR adaptation training in healthy normal subjects. There was no significant change in VOR latency across subjects; however, there was a significant decrease in VOR gain of − 6.0 ± 4.5%. These data suggest that during high-frequency head rotations delay/latency is interpreted as a changing instantaneous VOR gain demand. Although the gain demand in this study had a complex trajectory, adaptation was evident with the VOR seeming to use an average of the instantaneous gain demand.

We sought to determine whether repeated vestibulo-ocular reflex (VOR) adaptation training to increase the VOR gain (eye/head velocity) had a lasting effect in normal subjects and whether there was a retinal image slip tolerance threshold for VOR adaptation. We used the unilateral incremental VOR adaptation technique and horizontal active (self-generated, predictable) head impulses as the vestibular stimulus. Both active and passive (imposed, unpredictable) head impulse VOR gains were measured before and after unilateral incremental VOR adaptation training. The adapting side was pseudo-randomized for left or right. We tested ten normal subjects over one block (10 sessions over 12 days) of VOR adaptation training and testing, immediately followed by a second block (5 sessions over 19 days) of testing only without training. Our findings show robust short-term VOR adaptation of ~ 10 % immediately after each 15-min training session, but that the daily pre-adaptation gain was most different on days 1 and 2, and for subsequent training days before saturating to ~ 5 % greater than the pre-adaptation gain on day 1. This increase was partially retained for 19 days after regular training stopped. The data suggest that stable vision in normal subjects is maintained when there is

The study objective was to understand how the contralesional labyrinth contributes to gaze and gait stability after unilateral vestibular deafferentation (UVD). Head impulse testing (vHIT) was completed in 37 individuals [22 women (59%); age 52.13 ± 11.59 yr, mean ± SD] with UVD from vestibular schwannoma resection. Compensatory saccades (CS) and vestibulo-ocular reflex (VOR) gain were analyzed for both ipsilesional and contralesional impulses. Gait speed (10-m walk test) and endurance (2-min walk test) were collected for 35 individuals. CS were recruited during contralesional head rotation regardless of VOR gain on either the ipsilesional [ρ = 0.21 (−0.14, 0.57); Spearman rank (95% confidence interval)] or contralesional side [ρ = −0.04 (−0.42, 0.35)]. Additionally, the latency of these CS (151.19 ± 52.41 ms) was similar to that of CS generated during ipsilesional rotation (165.65 ± 21.62 ms; P = 0.159). CS recruited during ipsilesional vHIT were of a higher velocity ( P < 0.001) and greater frequency ( P < 0.001) compared with contralesional CS. VOR gain asymmetry was significantly correlated with gait speed [ρ = −0.37 (−0.73, −0.01)], yet individual VOR gain was not correlated [ipsilesional: ρ = 0.17 (−0.20, 0.55); contralesional: ρ = −0.18 (−0.52, 0.15)]. Our data reveal CS are recruited at similar latencies without correlation to VOR gain or direction of head rotation, and that the central integration of ipsilesional and contralesional vestibular afference correlates with gait. Together, our data suggest the brain considers vestibular afference from both sides when generating related behavioral output after UVD. NEW & NOTEWORTHY After unilateral vestibular deafferentation, compensatory saccades (CS) have similar latencies regardless of the direction of head rotation, and those CS generated during contralesional head rotation are unrelated to extent of vestibular loss. Additionally, the extent of asymmetry in residual vestibular function, not the extent of vestibular loss, correlates with gait speed. Our data suggest a common mechanism is responsible for the generation of CS and restoration of gait speed in vestibular compensation.

Gaze stability exercises are a critical component of vestibular rehabilitation for individuals with vestibular hypofunction and many studies reveal the rehabilitation improves functional performance. However, few studies have examined the vestibular physiologic mechanisms (semicircular canal; otolith) responsible for such recovery after patients with vestibular hypofunction complete gaze and gait stability exercises. The purpose of this study was to compare behavioral outcome measures (i.e., visual acuity during head rotation) with physiological measures (i.e., gain of the vestibulo-ocular reflex) of gaze stability following a progressive vestibular rehabilitation program in patients following unilateral vestibular deafferentation surgery (UVD). We recruited n = 43 patients (n = 18 female, mean 52 ± 13 years, range 23–80 years) after unilateral deafferentation from vestibular schwannoma; n = 38 (25 female, mean 46.9 ± 15.9 years, range 22–77 years) age-matched healthy controls for dynamic visual acuity testing, and another n = 28 (14 female, age 45 ± 17, range 20–77 years) healthy controls for video head impulse testing. Data presented is from n = 19 patients (14 female, mean 48.9 ± 14.7 years) with UVD who completed a baseline assessment ~6 weeks after surgery, 5 weeks of vestibular physical therapy and a final measurement. As a group, subjective and fall risk measures improved with a meaningful clinical relevance. Dynamic visual acuity (DVA) during active head rotation improved [mean ipsilesional 38.57% ± 26.32 (n = 15/19)]; mean contralesional 39.96% ± 22.62 (n = 12/19), though not uniformly. However, as a group passive yaw VOR gain (mean ipsilesional pre 0.44 ± 0.18 vs. post 0.44 ± 0.15; mean contralesional pre 0.81 ± 0.19 vs. post 0.85 ± 0.09) did not show any change (p ≥ 0.4) after rehabilitation. The velocity of the overt compensatory saccades during ipsilesional head impulses were reduced after rehabilitation; no other metric of oculomotor function changed (p ≥ 0.4). Preserved utricular function was correlated with improved yaw DVA and preserved saccular function was correlated with improved pitch DVA. Our results suggest that 5 weeks of vestibular rehabilitation using gaze and gait stability exercises improves both subjective and behavioral performance despite absent change in VOR gain in a majority of patients, and that residual otolith function appears correlated with such change.

One drawback of passivating contacts in crystalline silicon solar cells is the current loss due to parasitic absorption within the involved material layers. When employed on an illuminated side of the cell, the full spectrum of the incident light will be partly absorbed before reaching the silicon bulk. Additionally, near-infrared (NIR) absorption can substantially reduce the cell's NIR spectral response (SR) also when employed on the non-illuminated side. As those losses are hard to measure directly, optical modeling is crucial for their quantification. This paper presents an extension to an analytical light-trapping model to account for parasitic absorption in the near-surface region via a new parameter Appp (absorbed fraction per perpendicular pass). We test the model by analyzing i) reflectance measurements on samples with varying doping profiles, ii) SR measurements on TOPCon solar cells with varying back-side poly-silicon layers, and iii) SR measurements of a bifacial silicon heterojunction cell. We show that the model can well be calibrated by fitting a single value for Appp to reflectance measurements. This enables a quantification of the parasitic absorption loss without requiring knowledge of all layer's optical properties. The model also is able to predict parasitic absorption in TOPCon cells when knowing the thickness and doping density of the poly-Si layer. Having proven the usefulness of Appp to represent parasitic absorption as a single-valued quantity, we suggest Appp as a third figure of merit for the quality of a passivating contact, next to the recombination parameter J0c and the contact resistivity rc.

OBJECTIVE Describe the implementation and effects of Mobile Acute Care for Elders (MACE) consultation at a Veterans Affairs Medical Center (VAMC). DESIGN Retrospective cohort analysis. INTERVENTION Veterans aged 65 or older who were admitted to the medicine service between October 1, 2012, and September 30, 2014, were screened for geriatric syndromes via review of medical records within 48 hours of admission. If the screen was positive, the MACE team offered the admitting team a same-day consultation involving comprehensive geriatric assessment and ongoing collaboration with the admitting team and supportive services to implement patient-centric recommendations for geriatric syndromes. RESULTS Veterans seen by MACE (n = 421) were compared with those with positive screens but without consultation (n = 372). The two groups did not significantly differ in age, comorbidity, sex, or race. All outcomes (30-day readmission, 30-day mortality, readmission costs) were in the expected direction for patients receiving MACE but did not reach statistical significance. Patients receiving MACE had lower odds of 30-day readmission (11.9% vs 14.8%; odds ratio [OR] = 0.82; 95% confidence interval [CI] = 0.54-1.25; p = .360) and 30-day mortality (5.5% vs 8.6%; OR = 0.64; CI = 0.36-1.12; p = .115), and they had lower 30-day readmission costs (MACE $15,502; CI = $12,242-$19,631; comparison = $18,335; CI = $14,641-$22,962; p = .316) than those who did not receive MACE after adjusting for age and Charlson Comorbidity Index. CONCLUSION Our MACE consultation model for older veterans with geriatric syndromes leverages the limited supply of clinicians with expertise in geriatrics. Although not statistically significant in this study of 793 subjects, MACE patients had lower odds of 30-day readmission and mortality, and lower readmission costs. J Am Geriatr Soc 67:818-824, 2019.

Photoluminescence imaging is a fast and powerful technique to extract information about the nonuniformity of the recombination properties of silicon wafers and solar cells. In conventional photoluminescence imaging, where a uniform illumination is used, lateral carrier flows within the sample lead to smeared and quantitatively inaccurate results. In this study, a modified photoluminescence imaging setup, based on an adjustable spatially nonuniform excitation light source, is presented. With this setup, a laterally uniform excess carrier concentration is achieved across samples with nonuniform recombination properties by adaptively adjusting the light intensity at each position across the sample. Uniform photoluminescence images are obtained and the sample nonuniformity is extracted from the nonuniform excitation image that is applied. Without the presence of lateral carrier flows, carrier smearing effects are largely suppressed. Meanwhile, photoluminescence imaging-based quantitative analysis methods, such as carrier lifetime images, metastable defect imaging, etc., will greatly benefit from the fact that the sample is at a uniform excess carrier density.

The main goal of a solar cell's contact is to simultaneously minimize the contact resistivity ρ cont and the effective recombination, the latter often expressed via J0, cont. To model the resulting solar cell characteristics, the simplest approach is to use those two measurable quantities as an effective boundary condition. Within crystalline silicon solar cell modeling, this “lumped” modeling approach is well valid for classical contacts, which feature high doping near the surface. Contacts to lowly doped silicon in contrast require a suitable stack of materials deposited onto the absorber surface to simultaneously induce band bending via an electrical barrier (field-effect passivation), provide chemical passivation, and efficiently extract majority carriers. Such “passivating contacts” often show effects not reproducible by the lumped modeling approach, e.g., non-ohmic contact resistivity, injection-dependent recombination, and voltage drops independent of current extraction. In this paper, we explore the suitability of the basic metal–insulator–semiconductor theory, employed as a boundary condition to a numerical model of the semiconductor transport in the absorber, to represent such effects of passivating contacts. We show that with only very few input parameters, several relevant experimental observations can be quantitatively replicated: temperature dependence of the fill factor of solar cells featuring tunnel-oxide passivating contacts, as well as implied versus external open-circuit voltage losses for heterojunction solar cells. While being the focus of this paper, the presented approach is well applicable also beyond crystalline silicon cells.

N-type multicrystalline silicon (mc-Si) is a promising alternative to the dominant p-type mc-Si for solar cells because it combines the cost advantages of mc-Si while benefiting from higher tolerance to transition metal contamination. A detailed understanding of the relative roles of point defect and precipitated transition metals has enabled advanced processing and high minority carrier lifetimes in p-type mc-Si. This contribution extends that fundamental understanding to Fe contamination in n-type mc-Si, helping enable processing of this material into an economical and high-performance photovoltaic device. By directly correlating micro-photoluminescence-based minority carrier lifetime mapping and synchrotron-based micro-X-ray fluorescence mapping of Fe-rich precipitates, we develop a quantitative, physical understanding of the recombination activity of Fe-rich precipitates in n - type mc-Si.

The healthy vestibulo-ocular reflex (VOR) ensures that images remain on the fovea of the retina during head rotation to maintain stable vision. VOR behavior can be measured as a summation of linear and nonlinear properties although it is unknown whether asymmetric VOR adaptation can be performed synchronously in humans. The purpose of the present study is twofold. First, examine whether the right and left VOR gains can be synchronously adapted in opposing directions. Second, to investigate whether the adaptation context transfers between both sides. Three separate VOR adaptation sessions were randomized such that the VOR was adapted Up-bilaterally, Down-bilaterally, or Mixed (one side up, opposite side down). Ten healthy subjects completed the study. Subjects were tested while seated upright, 1 meter in front of a wall in complete dark. Each subject made active (self-generated) head impulse rotations for 15 min while viewing a gradually increasing amount of retinal slip. VOR training demand changed by 10% every 90 s. The VOR changed significantly for all training conditions. No significant differences in the magnitude of VOR gain changes between training conditions were found. The human VOR can be simultaneously driven in opposite directions. The similar magnitude of VOR gain changes across training conditions suggests functionally independent VOR circuits for each side of head rotation that mediate simultaneous and opposing VOR adaptations.NEW & NOTEWORTHY Our results indicate that humans have the adaptive capacity for concurrent and opposing directions of vestibulo-ocular reflex (VOR) motor learning. Context specificity of VOR adaptation is dependent on the error signal being unilateral or bilateral, which we illustrate via a lack of VOR gain transfer using unique adaptive demands.

In this contribution, we present our recent results for high efficiency multicrystalline silicon solar cells. Based on n-type high-performance multicrystalline silicon substrates in combination with the TOPCon solar cell concept featuring a full area passivating back contact and a boron-diffused emitter as well as a plasma-etched black-silicon texture at the front side, a certified conversion efficiency of 22.3% has been achieved, which is currently the world record efficiency for multicrystalline silicon solar cells. A detailed loss analysis of the record solar cell batch discloses the nature of the remaining loss mechanisms, revealing the route for further improvements. We observe an efficiency gap between the multicrystalline and the FZ reference solar cells of ~1%abs. Compared to the FZ reference cells, the mc-Si cells also feature a significantly larger scattering in Voc and Jsc as well as a fill factor loss of ~1.5%abs. We show that the scattering in Jsc correlates with the area fraction of recombination-active structural crystal defects and the scattering in Voc additionally with lateral emitter-induced inhomogeneities. The fill factor loss is attributed to the general presence of strongly recombination-active grain boundaries. A detailed loss analysis of the record mc-Si solar cell shows that the major electrical losses are due to recombination at grain boundaries (0.7%abs) and recombination in the emitter (0.6%abs). By reducing these electrical loss channels, e.g. by an improved crystallization process together with a hydrogenation of the bulk and application of an adapted emitter, we expect to reach efficiencies for mc-Si solar cells in the range of 23%.

We sought to determine if separating vestibulo-ocular reflex (VOR) adaptation training into training blocks with a consolidation (rest) period in between repetitions would result in improved VOR adaptation and retention. Consolidation of motor learning refers to the brain benefitting from a rest period after prior exposure to motor training. The role of consolidation on VOR adaptation is unknown, though clinicians often recommend rest periods as a part of vestibular rehabilitation. The VOR is the main gaze stabilising system during rapid head movements. The VOR is highly plastic and its gain (eye/head velocity) can be increased via training that induces an incrementally increasing retinal image slip error signal to drive VOR adaptation. The unilateral incremental adaptation technique typically consists of one 15-min training block leading to an increase in VOR gain of ~ 10 % towards the training side. We tested nine normal subjects, each over six separate sessions/days. Three training protocols/sessions were 5 min each (1 × 5-min training) and three training protocols/sessions were 55 min each. Each 55-min protocol comprised 5-min training, 20-min rest, 5-min training, 20-min rest, 5-min training (3 × 5-min training). Active and passive VOR gains were measured before and after training. For training with consolidation breaks, VOR gain retention was measured over 1 h. The VOR gain increase after 1 × 5-min training was 3.1 ± 2.1 % (P

Despite the common complaints of dizziness and demyelination of afferent or efferent pathways to and from the vestibular nuclei which may adversely affect the angular vestibulo-ocular reflex (aVOR) and vestibulo-spinal function in persons with multiple sclerosis (PwMS), few studies have examined gaze and dynamic balance function in PwMS. (1) Determine the differences in gaze stability, dynamic balance and participation measures between PwMS and controls, (2) Examine the relationships between gaze stability, dynamic balance and participation. Nineteen ambulatory PwMS at fall-risk and 14 age-matched controls were recruited. Outcomes included (1) gaze stability (angular aVOR gain [ratio of eye to head velocity]; number of compensatory saccades [CS] per head rotation; CS latency; gaze position error; coefficient of variation [CV] of aVOR gain), (2) dynamic balance (functional gait assessment, FGA; four square step test), and (c) participation (dizziness handicap inventory; activities-specific balance confidence scale). Separate independent t-tests and Pearson's correlations were calculated. PwMS were age = 53 ± 11.7 years and had 4.2 ± 3.3 falls/year. PwMS demonstrated significant (P < 0.05) impairments in gaze stability, dynamic balance and participation measures compared to controls. CV of aVOR gain and CS latency were significantly correlated with FGA. Deficits and correlations across a spectrum of disability measures highlight the relevance of gaze and dynamic balance assessment in PwMS. Anat Rec, 301:1852-1860, 2018. © 2018 Wiley Periodicals, Inc.

Balance problems and frequent falls are common among clients with Cerebellar Ataxia (CA). CA is not a disease by itself but a collection of symptoms due to the involvement of cerebellum or its pathways. Presently the treatment for balance problems for CA is not standardized. Interventions available to improve balance are not specific to symptoms presentation. Functionally the cerebellum is divided into the spinocerebellum, vestibulocerebellum and corticocerebellum. Each functional zone has a distinct role in maintaining balance. Therefore, the presentation of symptoms will vary according to the functional zone involved. Pre-screening clients with CA for identifying the part of cerebellum involved will facilitate clinicians to provide tailor-made interventions for targeting specific symptoms for better outcomes. Pre-screening clients with CA according to the part of cerebellum involved is not in practice and our study will introduce this concept. We hypothesize pre-screening participants with spinocerebellar ataxia (SCA) for the involvement vestibulocerebellum followed by prescribing vestibulocerebellum targeted exercises will have better outcomes when compared to conventional balance training. We plan to conduct two related studies. In study 1 we will screen participants with CA for the involvement of vestibulocerebellum. In study 2, the effects of vestibulocerebellum targeted balance exercises on balance will be studied. We will assess the Subjective Visual Vertical (SVV) deviation and postural sway pattern to screen participants into people with and without vestibulocerebellar involvement. SVV deviation will be estimated using a computerized Subjective Visual Vertical (cSVV) device and postural sway pattern will be assessed using the limits of stability program of the Bertec© Balance system. The obtained SVV deviation scores will be used to derive at cut-off scores to discriminate clients with and without vestibulocerebellar involvement. The second study will test the treatment effects of conventional exercises plus vestibulocerebellum targeted exercises to improve balance by correcting SVV deviation in SCA with vestibulocerebellar involvement. The intervention is planned as 12 one-to-one sessions over three months period. Participants will be reassessed after the intervention and 3 months post-intervention. The findings of this cutting-edge research are extremely important to the clinicians, researchers and clients with SCA.

A new approach to model edge recombination in silicon solar cells is presented. The model accounts for recombination both at the edge of the quasi-neutral bulk as well as at an exposed space-charge-region (SCR), the latter via an edge-length-specific diode property with an ideality factor of 2: a localized J02, edge. The model is implemented in Quokka3, where the $J_{02,edge}$ is applied locally to the edges of the three-dimensional geometry, imposing less simplifying assumptions compared with the common way of applying it as an external diode. A “worst-case” value for $J_{02,{\rm{edge}}}$ , assuming very high surface recombination, is determined by fitting to full detailed device simulations which resolve the SCR recombination. A value of $\sim \text{19 nA/cm}$ is found, which is shown to be largely independent of device properties. The new approach is applied to model the impact of edge recombination on full cell performance for a substantial variety of device properties. It is found that recombination at the quasi-neutral bulk edge does not increase the $J_{02}$ of the dark J–V curve, but still shows a nonideal impact on the light J–V curve similar to the SCR recombination. This needs to be considered in the experimental evaluation of edge losses, which is commonly performed via fitting $J_{02}$ to dark J–V curves.

Multiple psychosocial factors influence help-seeking behavior among immigrants, but studies have focused on separate issues in single cultural groups. This study tested a model of help-seeking behavior among three ethnically different immigrant groups. Participants were 1356 Somali, Russian, and Kurdish immigrants (18-64 years). They reported past traumatic events, social network, acculturation indices, trust in services, and mental health as well as usage of mental and somatic health services. Structural equation modeling (SEM) with multigroup procedure was applied. First, past traumatic events were associated with seeking more mental health services, indirectly mediated through increased risk for mental health problems in all three ethnic groups. Second, acculturation played a significant role in the use of mental and somatic health services only in Kurds and social networks in Kurds and Russians. The unique culturally influenced dynamics in help-seeking behavior should be considered in the development of health services.

People with Multiple Sclerosis (PwMS) experience a wide range of symptoms that can alter function and limit activity and community participation. Symptoms including sensory changes, weakness, fatigue and others have been well documented. However, symptoms related to changes in vestibular related function, including gaze and postural stability have not been fully explored. While some recent studies have begun to provide insight into these deficits in PwMS and have explored the use of rehabilitation paradigms for their management, much remains unknown about the full extent of these deficits. Therefore, this study aimed to characterize the presence of gaze and postural stability deficits in measures across the World Health Organization International Classification of Functioning, Disability, and Health (WHO ICF) and to examine how deficits in domains of body structure and function and activity contribute to participation level limitations.Baseline data from 41 PwMS (mean(SD) age = 53.9(11.2), 78% female) enrolled as part of a randomized clinical trial were used in this analysis. Measures of gaze and postural stability from the ICF domains of body structure and function (Vestibular ocular reflex [VOR] gain and postural sway area), activity (computerized dynamic visual acuity [cDVA] and MiniBEST test), and participation (Dizziness handicap inventory [DHI] and Activities Balance Confidence [ABC] scale) along with demographic data were used to characterize the sample. To explore relationships between ICF domains for gaze and postural stability, univariate correlations were performed between measures from each domain using Pearson's correlations. Separate multivariate regression models examined how measures from the body structure and function and activity domains contributed to the variance in the participation level outcomes. Variance explained by the models was quantified using R-squared statistic and contribution of the independent variables were quantified using the beta coefficient (p 0.05).Correlation analysis demonstrated significant relationships in the postural stability measures across domains. Specifically, between postural sway area on a firm surface and MiniBEST test score (r = -.48;p 0.01) and MiniBEST test score and ABC score (r = 0.5;p 0.01). Significant correlations were also found between the gaze stability measures of horizontal and vertical VOR gain (r = .68;p 0.001), horizontal VOR gain and dynamic visual acuity (r = .38;p = 0.02), and vertical VOR gain and dynamic visual acuity (r = .54;p 0.001). Regression models assessing postural stability, found that only the MiniBEST score significantly contributed to the variance in ABC score (p = 0.01) and the full model explained 34% of the variance in ABC score. Regression modeling of gaze stability outcomes did not produce any variable that significantly contributed to the variance in DHI score and the full model explained 18% of the variance in DHI score.PwMS in this sample demonstrated deficits in gaze and postural stability across the domains of the WHO ICF compared to past samples of PwMS and healthy cohorts. Correlation between measures in the different domains were present, but no strong relationship between measures of body structure and function, activity and participation level outcomes were observed. This lack of relationship across the domains is likely contributed to the relatively small sample size, the high level of variability observed in the outcomes, and the diverse presentation often seen in PwMS.

In order to push silicon solar cell efficiencies further towards their limit, as well as to ensure accuracy of luminescence based characterization techniques, an accurate modeling of radiative recombination is important. It is well-known that the radiative recombination coefficient Brad of silicon shows a substantial charge carrier density dependence (c-dependence), often modelled via the scaling factor Brel quantified by Altermatt et al. Another effect lowering the total radiative recombination is photon recycling (PR), which depends mainly on the width and optical properties of the sample. PR also depends on free-carrier absorption (FCA), which introduces a further c-dependence. This work comprehensively reassesses and quantifies those influences on radiative recombination in silicon for photovoltaic (PV) applications. Firstly, it is evidenced that Altermatt's Brel model is dominated by the effect of band-gap narrowing (BGN). This clarifies that it should not be combined with a different BGN model to avoid modeling inconsistencies. It is thereby further confirmed that the band-to-band absorption coefficient of silicon does not show a relevant c-dependence for PV conditions. Next, a PR model is suggested which calculates a scaling factor Brel,PR. The model is proven useful in improving the interpretation of very high lifetime measurements. Finally, it is found that the c-dependence introduced by FCA affects the direct proportionality between luminescence signal and radiative recombination beyond charge carrier densities of 1016 cm−3 for samples thicker than typical wafer widths, and should then be considered in characterization techniques like e.g. calibrated lifetime measurements via photoluminescence.

An accurate electrical device characterization of hybrid organic-inorganic halide perovskite solar cells (PSCs) is an important prerequisite for further improvement and industrial transfer of this promising photovoltaic technology. In this work, we study the nonlinearity of current versus irradiance as well as the temperature dependence of PSCs in a spectrally resolved manner by highly accurate differential external quantum efficiency (EQE) measurements. We investigate three different types of PSCs fabricated by different research groups. The nonlinearity of all samples is found to be spectrally invariant, which significantly simplifies spectral mismatch corrections. We demonstrate that misinterpretation of EQE measurements can result in a more than 10% relative error in efficiency measurements, if solar simulators are adjusted to photocurrents determined from differential EQEs. For obtaining an accurate integrated photocurrent from EQEs, we introduce a new, convenient approach that accounts for cell nonlinearities but avoids the time-consuming full analysis of spectrally resolved nonlinearity. Moreover, for the samples investigated here, it is shown that the differential EQE measured at 0.35 suns bias irradiance represents a reasonably good estimate of the actual EQE at 1 sun. Furthermore, we determine spectrally resolved temperature coefficients (TCs) and show how the band gap blue shift varies with perovskite absorber and temperature.

The degradation kinetics of multicrystalline silicon solar cells and wafers at elevated temperature (often termed “LeTID”) depend on the specific temperature and injection conditions. We apply different forward biases in the dark at a constant temperature of ~75 °C to industrial passivated emitter rear contacted (PERC) solar cells fabricated on p-type multicrystalline wafers from a variety of material producers and determine the degradation rate constant in dependence of the excess carrier density at the p-n junction. We find that whereas the specific material properties influence the degradation extent, the degradation rate constant is comparable for all materials but depends on the excess carrier concentration. This implies involvement of one electron in the rate-limiting step of LeTID defect formation. The result not only is an important contribution to elucidate the physical mechanism underlying LeTID, but can also be used as a guideline for devising degradation tests of multicrystalline silicon wafers and solar cells.

33rd European Photovoltaic Solar Energy Conference and Exhibition; 218-225, This paper discusses degradation phenomena in crystalline silicon. We present new investigations of the light- and elevated temperature induced degradation (LeTID) of multicrystalline silicon. The investigations provide insights into the defect parameters as well as the diffusivity and solubility of impurity species contributing to the defect. We discuss possible defect precursor species and can rule out several metallic impurities. We find that an involvement of hydrogen in the defect could explain the characteristic observations for LeTID. Furthermore, we demonstrate analogies to the light-induced degradation mechanisms at elevated temperatures observed in floatzone silicon, where several experimental results also indicate an involvement of hydrogen in the defect. Based on the similarities between multicrystalline and floatzone silicon we suggest that both degradation phenomena might be caused by the same or similar defects. As we do not expect large concentrations of cobalt in floatzone silicon, we suggest that complexes of intrinsic lattice defects and hydrogen might cause both degradation phenomena.

The vestibulo-ocular reflex (VOR) is the main retinal image stabilising mechanism during rapid head movement. When the VOR does not stabilise the world or target image on the retina, retinal image slip occurs generating an error signal that drives the VOR response to increase or decrease until image slip is minimised, i.e. VOR adaptation occurs. Visual target contrast affects the human smooth pursuit and optokinetic reflex responses. We sought to determine if contrast also affected VOR adaptation. We tested 12 normal subjects, each over 16 separate sessions. For sessions 1-14, the ambient light level (lx) during adaptation training was as follows: dark, 0.1, 0.2, 0.3, 0.5, 0.7, 1, 2, 8, 16, 32, 64, 128 and 255 lx (light level for a typical room). For sessions 15-16, the laser target power (related to brightness) was halved with ambient light at 0 and 0.1 lx. The adaptation training lasted 15 min and consisted of left/right active head impulses. The VOR gain was challenged to increment, starting at unity, by 0.1 every 90 s for rotations to the designated adapting side and fixed at unity towards the non-adapting side. We measured active and passive VOR gains before and after adaptation training. We found that for both the active and passive VOR, there was a significant increase in gain only towards the adapting side due to training at contrast level 1.5 k and above (2 lx and below). At contrast level 261 and below (16 lx and above), adaptation training resulted in no difference between adapting and non-adapting side gains. Our modelling suggests that a contrast threshold of ~ 1000, which is 60 times higher than that provided by typical room lighting, must be surpassed for robust active and passive VOR adaptation. Our findings suggest contrast is an important factor for adaptation, which has implication for rehabilitation programs.

Minimizing carrier recombination at interfaces is of extreme importance in the development of high-efficiency photovoltaic devices and for bulk material characterization. Here, we investigate a temporary room temperature superacid-based passivation scheme, which provides surface recombination velocities below 1 cm/s, thus placing our passivation scheme amongst state-of-the-art dielectric films. Application of the technique to high-quality float-zone silicon allows the currently accepted intrinsic carrier lifetime limit to be reached and calls its current parameterization into doubt for 1 Ω·cm n-type wafers. The passivation also enables lifetimes up to 65 ms to be measured in high-resistivity Czochralski silicon, which, to our knowledge, is the highest ever measured in Czochralski-grown material. The passivation strategies developed in this work will help diagnose bulk lifetime degradation under solar cell processing conditions and also help quantify the electronic quality of new passivation schemes.

Multicrystalline (mc) n-type silicon has proven to be a suitable substrate for the fabrication of highly efficient mc-Si solar cells. In this paper, we elaborate the impact of base material parameters on the efficiency potential of n-type mc-Si solar cells featuring a boron-diffused front side emitter and a full-area passivating rear contact (TOPCon). The electrical material quality can be significantly improved by replacing the standard crystallization process with a seed-assisted growth for crystallization of high-performance (HP) mc silicon. Using high-purity quartz crucibles or larger crucibles in combination with an optimization of the grain boundary area fraction with an adapted seed structure leads to further improvements of the material quality in terms of charge carrier lifetimes. However, not only the charge carrier lifetime, but also the base resistivity is of crucial importance for the efficiency potential depending on the cell concept. Based on experimental data and simulations, we assess the optimal range for the base resistivity and the wafer thickness for n-type mc-Si TOPCon solar cells. With the optimal material parameters, an “efficiency limiting bulk recombination analysis” (ELBA) reveals an efficiency potential in the range of 22.5% for n-type mc-Si TOPCon solar cells. Finally, we fabricated TOPCon solar cells based on optimized n-type HP mc-Si substrate and demonstrate a certified efficiency of 21.9%, which is the highest efficiency reported for multicrystalline silicon solar cells so far.

In this contribution, we demonstrate a route for efficiencies exceeding 22% with n-type multicrystalline (mc) silicon solar cells based on the TOPCon cell concept featuring a boron-diffused front side emitter and a full-area passivating rear contact. By applying a “high-performance” (HP) crystallization process with an adapted seed structure in order to obtain an optimized grain boundary area fraction, we reduce recombination losses in the HP mc-Si material to a minimum. We discuss the electrical properties of the optimized n-type HP mc-Si, which features very low material-related efficiency losses of approximately 0.5% abs and, thus, enables an efficiency potential of 22.6% with regard to a cell limit of 23.1% of the TOPCon cell concept adapted for multicrystalline silicon. Results at the device level reveal a record efficiency of 21.9%, which is the highest efficiency reported for a multicrystalline silicon solar cell. Finally, we discuss the deviations between the predicted efficiency potential and the solar cell results.

Light- and elevated temperature-induced degradation (LeTID) in multicrystalline silicon can reduce the efficiency of solar cells significantly. We analyse the influence of the firing temperature profile on the degradation behaviour of neighbouring mc-Si wafers, varying peak temperatures above 800°C (measured) as well as heating and cooling ramps. The degradation intensity is determined by the normalized defect concentrations N t * using spatially resolved and lifetime calibrated photoluminescence images. Wafers which were fired in a standard industrial fast firing furnace with steep ramps suffer from significant LeTID whereas samples that were subjected to the same or even higher peak temperatures but with slower heating and cooling rates hardly degrade. A spatially resolved analysis of N t * over the whole wafer area shows that at the beginning of the experiment, the degradation is restricted to low-lifetime areas around dislocation clusters. After several hours, a very strong degradation is observed also in initially good grains. The possible roles of metallic impurities and hydrogen in-diffusion are discussed.

Silicon solar cells featuring the highest conversion efficiencies are made from monocrystalline n-type silicon. The superior crystal quality of high-performance multicrystalline silicon (HP mc) in combination with the inherent benefits of n-type doping (higher tolerance to common impurities) should allow the fabrication of high-efficiency solar cells also on mc silicon. In this paper, we address high-efficiency n-type HP mc solar cells with diffused boron front emitter and full-area passivating rear contact (TOPCon). n-type HP mc silicon was crystallized at Fraunhofer ISE featuring a very high average lifetime in the range of 600 μ s (i.e., diffusion length >800 μ m) after application of all high-temperature steps necessary for cell fabrication. Using a “black silicon” front texture we have achieved a weighted reflectance of ∼1% and simultaneously a very good electrical performance, i.e., J 0 e values of ≤ 60 fA/cm2 for a 90 Ω/sq emitter. The resulting n-type mc silicon solar cells show certified conversion efficiencies up to 21.9%, representing the current world record for mc silicon solar cells.

Confocal micro-Raman spectroscopy allows for spatially resolved measurements of the phonon energy in silicon, which is correlated to mechanical stress. Mechanical stress is a tensorial quantity. For the confocal measurement geometry and certain crystal orientations approximations have been derived in the past which correlate the shift of the Raman frequency to a scalar stress value. For optimization of mono-crystalline solar cell manufacturing steps the determination of induced mechanical stress from the top view perspective is desirable. However, this method is so far restricted to planar wafers or cross sections. we find that the anti-reflection surface texture strongly affects the measurement result. To enable quantitative stress determination of alkaline textured silicon a suited measurement procedure is investigated using 3-point bended solar cell segments. Preceding elasticity test revealed Young’s module and allowed a prediction of maximum stress values for any bending radius. We propose a measurement procedure which yields an observable shift of the Raman frequency proportional to the induced stress. We state the requirements for determination of a calibration factor to quantify stress on any alkaline textured solar cell. Adapting the conversion factors allows calibrated measurements for textures with different average pyramid heights. By varying the numerical aperture and the focus setting even changes of the induced stress within the texture pyramids are resolved.

For solar cell application, the stability of interface passivation quality to in-field conditions is crucial. We have performed an experiment to test the resilience of different aluminium oxide based passivation schemes to illumination at 75 °C. Different thermal treatments to activate the passivation and/or simulate contact firing were performed before light soaking. The experiment was performed on 1 Ωcm float-zone silicon of both p- and n-type doping. The study demonstrates that good passivation quality can be achieved both by atomic layer deposition and by PECVD and that addition of silicon nitride capping layers greatly enhances thermal stability. On p-type wafers a severe but temporary degradation of the electrical quality of the wafer bulk was observed during the first hours upon application of such capping layers. Besides this effect, reasonable temporal stability of the effective lifetime was observed for p-type samples while n-type samples featured excellent long-term stability.

BACKGROUND We have developed a non-invasive, behavioral measure of ocular alignment using a computer tablet, colored lenses, and touch screen software. OBJECTIVE The goal of this study was to determine if these tests differentiate healthy controls from patients with vestibular disorders. METHODS In the vertical alignment nulling test (VAN), subjects were asked to adjust a horizontal line that was offset vertically from a fixed horizontal line. In the torsional alignment nulling test (TAN) subjects were asked to adjust a line that was rotationally offset (i.e. clockwise) from a fixed horizontal line. We measured VAN and TAN in 14 healthy controls and 8 patients with known vestibular disorders. RESULTS Patients had significantly worse scores than controls on TAN, (mean 2.2 vs 0.75, p = 0.01), and no differences for scores compared to controls on VAN, (mean 0.4 vs 0.8, p = 0.07). CONCLUSIONS These results suggest that TAN, and possibly VAN, have potential for identifying misalignments in ocular position. After further technical development these tests might be useful in the future for screening patients in facilities that are not equipped to perform cervical and ocular vestibular evoked myogenic potentials.

Objectives/Hypothesis There is a large variation in vestibular rehabilitation (VR) results depending on type of therapy, adherence, and the appropriateness for the patient's level of function. A novel adaptive vestibular rehabilitation (AVR) program was developed and evaluated. Study Design Technology and procedure development, and prospective multicenter trial. Methods Those with complete unilateral vestibular hypofunction and symptomatic at least 3 months with a Dizziness Handicap Inventory (DHI) >30 were eligible. Patients were given a device to use with their own computer. They were instructed to use the program daily, with each session lasting about 10 minutes. The task consisted of reporting orientation of the letter C, which appeared when their angular head velocity exceeded a threshold. The letter size and head velocity required were adjusted based on prior performance. Performance on the task was remotely collected by the investigator as well as a weekly DHI score. Results Four patients aged 31 to 74 years (mean = 51 years) were enrolled in this feasibility study to demonstrate efficacy. Two had treated vestibular schwannomas and two had vestibular neuritis. Starting DHI was 32 to 56 (mean = 42), which was reduced to 0 to 16 (mean = 11.5) after a month of therapy, a clinically and statistically significant (P < .05) improvement. The three who continued therapy an additional month improved to a DHI of 4. Conclusions This AVR method has advantages over traditional VR in terms of cost and customization for patient ability and obtained a major improvement in symptoms. This study demonstrated a clinically and statistically significant decrease in symptoms after 4 weeks of therapy. Level of Evidence 2b Laryngoscope, 2017

Tilt suppression refers to both tilting the head away from an Earth vertical axis and a reduction of an induced horizontal nystagmus. This phenomenon of reducing an induced horizontal nystagmus involves a circuitry of neurons within the vestibular nuclei and the cerebellum (collectively referred to as velocity storage) and signals from the otolith end organs. Lesions involving this circuitry can disrupt tilt suppression of induced horizontal nystagmus. We investigated the clinical value of combining the horizontal head-shaking nystagmus test with tilt suppression in 28 patients with unilateral peripheral vestibular hypofunction and 11 patients with lesions affecting the central nervous system. Each of the subjects with peripheral vestibular lesions generated an appropriately directed horizontal nystagmus after head shaking that then suppressed the induced angular slow phase velocity on average 52 ± 17.6% following tilt down of the head. In contrast, patients with central lesions had very little ability to suppress post-head-shaking nystagmus (mean 3.4 ± 56%). We recommend tilting the head after head shaking as a useful clinical test to assist in the differential diagnosis of vertiginous patients. In the case of unilateral peripheral vestibular hypofunction, head tilt suppresses the induced nystagmus via influence of the otolith organ. In the case of central pathology, the inability to suppress the nystagmus is from lesions impairing the otolith mediation on the velocity storage circuitry.

Background Small, innate asymmetries between the left and right otolith organs can cause ocular misalignment with symptoms that include double vision and motion sickness. Additionally, ocular misalignment affects nearly 5% of the US population. We have developed a portable, non-invasive technology that uses subjective perception of binocular visual signals to estimate relative binocular alignment. New method and results The Vertical Alignment Nulling (VAN) and Torsional Alignment Nulling (TAN) tests ask subjects to view one red and one blue line on a tablet computer while looking through color-matched red and blue filters so that each eye sees only one of the lines. Subjects align the red and blue lines, which are initially vertically offset from one another during VAN or rotated relative to one another during TAN, until they perceive a single continuous line. Ocular misalignments are inferred from actual offsets in the final line positions. During testing, all binocular visual cues are eliminated by employing active-matrix organic light-emitting diode (AMOLED) technology and testing in darkness. VAN and TAN can accurately account for visual offsets induced by prisms, and test-retest reliability is excellent, with resolution better than many current standard clinical tests. Comparison with existing method(s) VAN and TAN tests are similar to the clinical Lancaster red-green test. However, VAN and TAN employ inexpensive, hand-held hardware that can be self-administered with results that are quickly quantifiable. Conclusions VAN and TAN provide simple, sensitive, and quantitative measures of binocular positioning alignment that may be useful for detecting subtle abnormalities in ocular positioning.

Human subjects placed in strong magnetic fields such as in an MRI scanner often feel dizzy or vertiginous. Recent studies in humans and animals have shown that these effects arise from stimulation of the labyrinth and are accompanied by nystagmus. Here, we measured the three-dimensional pattern of nystagmus using video eye tracking in five normal human subjects placed in a 7T MRI to infer which semicircular canals are activated by magnetic vestibular stimulation. We found that the nystagmus usually had a torsional as well as a horizontal component. Analysis of the relative velocities of the three eye movement components revealed that the lateral and anterior (superior) canals are the only canals activated, and by a similar amount.

The characterization and modeling of silicon solar cells under nonstandard conditions is an essential task in order to predict and optimize the annual yield when installed in the field. In this paper, focus is set on the temperature dependence of fundamental physical models for numerical device simulation of silicon solar cells. A wide range of industrially relevant solar cell concepts is simulated and compared to experimental data. The influence of fundamental physical models on the temperature dependence of the simulated devices is investigated. It is found that our simulations are in good agreement with experimental results for silicon solar cells that are limited by extrinsic defect or surface recombination. This is not the case for solar cells featuring carrier-selective contacts where intrinsic recombination processes, such as Auger recombination and radiative recombination, have a significant influence.

There is mounting evidence that maternal executive function (EF) plays a critical role in parenting behavior. However, the majority of the research on this topic has been conducted in low-risk samples. The purpose of the present study was to investigate whether individual differences in maternal EF are associated with parenting behavior in the high-risk, high adversity context of family homelessness. The study included 94 mothers and their children, ages 4 to 6 years, living in emergency homeless shelters. Mothers completed a battery of "hot" and "cool" EF tasks as well as a self-report questionnaire of perceived stress. Parenting measures were based on observed parent-child interactions that were later coded for harsh and positive parenting practices. Results indicated that hot EF in mothers was related to positive parenting. The relation between maternal planning ability, assessed by a cool EF task, and harsh parenting was also significant, but only for mothers reporting higher levels of stress. These findings add to a growing body of research suggesting that the influence of EF and other forms of cognitive control on parenting need to be interpreted within the context of environmental stress and adversity. (PsycINFO Database Record