1,597 research outputs found
Instrumentation of a high-sensitivity microwave vector detection system for low-temperature applications
We present the design and the circuit details of a high-sensitivity microwave
vector detection system, which is aiming for studying the low-dimensional
electron system embedded in the slots of a coplanar waveguide at low
temperatures. The coplanar waveguide sample is placed inside a phase-locked
loop; the phase change of the sample may cause a corresponding change in the
operation frequency, which can be measured precisely. We also employ a
double-pulse modulation on the microwave signals, which comprises a fast pulse
modulation for gated averaging and a slow pulse modulation for lock-in
detection. In measurements on real samples at low temperatures, this system
provides much better resolutions in both amplitude and phase than most of the
conventional vector analyzers at power levels below -65 dBm.Comment: 7 pages, 11 figures, 1 table, lette
Lignocellulose-based analytical devices: bamboo as an analytical platform for chemical detection
This article describes the development of lignocellulose-based analytical devices (LADs) for rapid bioanalysis in low-resource settings. LADs are constructed using either a single lignocellulose or a hybrid design consisting of multiple types of lignocellulose. LADs are simple, low-cost, easy to use, provide rapid response, and do not require external instrumentation during operation. Here, we demonstrate the implementation of LADs for food and water safety (i.e., nitrite assay in hot-pot soup, bacterial detection in water, and resazurin assay in milk) and urinalysis (i.e., nitrite, urobilinogen, and pH assays in human urine). Notably, we created a unique approach using simple chemicals to achieve sensitivity similar to that of commercially available immunochromatographic strips that is low-cost, and provides on-site, rapid detection, for instance, of Eschericia coli (E. coli) in water
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Physiological, behavioral and subjective sadness reactivity in frontotemporal dementia subtypes.
Frontotemporal dementia (FTD), a neurodegenerative disease broadly characterized by socioemotional impairments, includes three clinical subtypes: behavioral variant FTD (bvFTD), semantic variant primary progressive aphasia (svPPA) and non-fluent variant primary progressive aphasia (nfvPPA). Emerging evidence has shown emotional reactivity impairments in bvFTD and svPPA, whereas emotional reactivity in nfvPPA is far less studied. In 105 patients with FTD (49 bvFTD, 31 svPPA and 25 nfvPPA) and 27 healthy controls, we examined three aspects of emotional reactivity (physiology, facial behavior and subjective experience) in response to a sad film. In a subset of the sample, we also examined the neural correlates of diminished aspects of reactivity using voxel-based morphometry. Results indicated that all three subtypes of FTD showed diminished physiological responding in respiration rate and diastolic blood pressure; patients with bvFTD and svPPA also showed diminished subjective experience, and no subtypes showed diminished facial behavior. Moreover, there were differences among the clinical subtypes in brain regions where smaller volumes were associated with diminished sadness reactivity. These results show that emotion impairments extend to sadness reactivity in FTD and underscore the importance of considering different aspects of sadness reactivity in multiple clinical subtypes for characterizing emotional deficits and associated neurodegeneration in FTD
Interpersonal prosodic correlation in frontotemporal dementia.
Communication accommodation describes how individuals adjust their communicative style to that of their conversational partner. We predicted that interpersonal prosodic correlation related to pitch and timing would be decreased in behavioral variant frontotemporal dementia (bvFTD). We predicted that the interpersonal correlation in a timing measure and a pitch measure would be increased in right temporal FTD (rtFTD) due to sparing of the neural substrate for speech timing and pitch modulation but loss of social semantics. We found no significant effects in bvFTD, but conversations including rtFTD demonstrated higher interpersonal correlations in speech rate than healthy controls
Synergistic Effect of 3D Current Collectors and ALD Surface Modification for High Coulombic Efficiency Lithium Metal Anodes
Improving the performance of Li metal anodes is a critical bottleneck to enable nextâ generation battery systems beyond Liâ ion. However, stability issues originating from undesirable electrode/electrolyte interactions and Li dendrite formation have impaired longâ term cycling of Li metal anodes. Herein, a bottomâ up fabrication process is demonstrated for a current collector for Li metal electrodeposition and dissolution composed of highly uniform vertically aligned Cu pillars. By rationally controlling geometric parameters of the 3D current collector architecture, including pillar diameter, spacing, and length, the morphology of Li plating/stripping upon cycling can be controlled and optimal cycling performance can be achieved. In addition, it is demonstrated that deposition of an ultrathin layer of ZnO by atomic layer deposition on the current collector surface can facilitate the initial Li nucleation, which dictates the morphology and reversibility of subsequent cycling. This coreâ shell pillar architecture allows for the effects of geometry and surface chemistry to be decoupled and individually controlled to optimize the electrode performance in a synergistic manner. Using this platform, Li metal anodes are demonstrated with Coulombic efficiency up to 99.5%, providing a pathway toward highâ efficiency and longâ cycle life Li metal batteries with reduced excess Li loading.A 3D current collector architecture based on vertically aligned Cu for Li metal anodes is reported. By rationally tuning geometric parameters and surface chemistry of the 3D architecture, the morphology of Li plating/stripping can be controlled. Leveraging the synergistic effects of the optimized geometry and interface modification, cycling of Li metal anodes is demonstrated with Coulombic efficiency up to 99.5%.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147805/1/aenm201802534-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147805/2/aenm201802534_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147805/3/aenm201802534.pd
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An idiographic statistical approach to clinical hypothesis testing for routine psychotherapy: A case study.
In order to develop more targeted, efficient, and effective psychotherapeutic interventions, calls have been made in the literature for greater use of idiographic hypothesis testing. Idiographic analyses can provide useful information regarding mechanisms of change within individuals over time during treatment. However, it remains unclear how clinicians might utilize idiographic statistical analyses during routine treatment to test clinical hypotheses, and in turn, guide treatment. We present an idiographic statistical framework for clinical hypothesis testing with routine treatment data that enables clinicians to examine a) whether the client's symptoms and hypothesized mechanisms change over time, b) whether trajectories of change reflect the timing of interventions, c) whether mechanisms predict subsequent symptoms, and d) whether relationships exist between multiple mechanisms, symptoms, or other treatment-related constructs over time. We demonstrate the utility of the approach for clinical hypothesis testing by applying it to routine treatment data collected from a 56 year-old male who presented with a combination of anger problems, anxiety, and depressive symptoms. We discuss how results from analyses can inform the case-formulation and guide clinical decision-making. We aim to make these methods more accessible by providing an online platform where clinicians can enter client data, test their clinical hypotheses using idiographic analyses, and utilize the results to disseminate their findings
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Emotion Recognition and Reactivity in Persons With Neurodegenerative Disease Are Differentially Associated With Caregiver Health.
Background and objectivesMotivated by the high rates of health problems found among caregivers of persons with neurodegenerative disease, we examined associations between deficits in two aspects of care recipients' socioemotional functioning and their caregivers' health.Research design and methodsIn 2 studies with independent samples (N = 171 and 73 dyads), caregivers reported on care recipients' emotion recognition and emotional reactivity. Caregiver health was assessed using both self-report measures (Studies 1 and 2) and autonomic nervous system indices (Study 2).ResultsLower emotion recognition in care recipients was linearly associated with worse self-reported health, faster resting heart rate, and greater physiological reactivity to an acoustic startle stimulus in caregivers. These effects held after accounting for a variety of risk factors for poor caregiver health, including care recipients' neuropsychiatric symptoms. Emotional reactivity showed a quadratic association with health, such that the lowest and highest levels of emotional reactivity in care recipients were associated with lower self-reported health in caregivers.Discussion and implicationsResults shed light on the unique associations between two aspects of care recipients' emotional functioning and caregivers' health. Findings suggest potential ways to identify and help caregivers at heightened risk for adverse health outcomes
Behavioral indices of positivity resonance associated with long-term marital satisfaction.
Positivity resonance-defined as a synthesis of shared positive affect, mutual care and concern, plus behavioral and biological synchrony-is theorized to contribute to a host of positive outcomes, including relationship satisfaction. The current study examined whether, in long-term married couples, behavioral indices of positivity resonance (rated using a new behavioral coding system) are associated with concurrent shared positive affect using a well-established dyadic-level behavioral coding system (i.e., Specific Affect Coding System: SPAFF), and whether positivity resonance predicts concurrent marital satisfaction independently from other affective indices. Long-term married couples completed a self-report inventory assessing marital satisfaction and were then brought into the laboratory to participate in a conversation about an area of marital disagreement while being videotaped for subsequent behavioral coding. Interrater reliability for positivity resonance behavioral coding was high (intraclass correlation coefficient: 0.8). Results indicated that positivity resonance is associated with frequency of shared positive affect using SPAFF. No associations were found between positivity resonance and frequencies of SPAFF-coded individual-level positive affect or shared negative affect. Additionally, positivity resonance predicted marital satisfaction independently from frequencies of SPAFF-coded shared positive affect and individual-level positive affect alone. The effect of positivity resonance on marital satisfaction also remained significant after controlling for overall affective tone of conflict conversation. These findings provide preliminary construct and predictive validity for positivity resonance behavioral coding, and highlight the possible role positivity resonance may play in building relationship satisfaction in married couples. (PsycInfo Database Record (c) 2020 APA, all rights reserved)
âChoking Under Pressureâ in Older Drivers
Aging can impair executive control and emotion regulation, affecting driver decision-making and behavior, especially under stress. We used an interactive driving simulator to investigate ability to make safe left-turns across oncoming traffic under pressure in 13 older (\u3e 65 years old) and 16 middle-aged (35-56 years old) drivers. Drivers made left-turns at an uncontrolled intersection with moderately heavy oncoming traffic. Gaps between oncoming vehicles varied and increased gradually from 2 s to 10 s. Drivers made two left-turns with a vehicle honking aggressively behind (pressure condition), and two left-turns without the honking vehicle (control condition). Results showed that middle-aged drivers made more cautious turning decisions under pressure (by waiting for larger and safer gaps, p \u3c .001), but older drivers did not. Further, older driver turning paths deviated under pressure compared to the control condition (p \u3c .05), but the middle-aged group did not. Moreover, across all subjects, better executive function was significantly correlated with larger increases of accepted gap size from control to honking (p \u3c .01). The findings suggest that older drivers are more sensitive to traffic challenges from environmental pressure and that neural models of older driver performance and safety must factor in age-related changes in executive control and emotion processing
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