1,943 research outputs found
Suppression of Zeeman gradients by nuclear polarization in double quantum dots
We use electric dipole spin resonance to measure dynamic nuclear polarization
in InAs nanowire quantum dots. The resonance shifts in frequency when the
system transitions between metastable high and low current states, indicating
the presence of nuclear polarization. We propose that the low and the high
current states correspond to different total Zeeman energy gradients between
the two quantum dots. In the low current state, dynamic nuclear polarization
efficiently compensates the Zeeman gradient due to the -factor mismatch,
resulting in a suppressed total Zeeman gradient. We present a theoretical model
of electron-nuclear feedback that demonstrates a fixed point in nuclear
polarization for nearly equal Zeeman splittings in the two dots and predicts a
narrowed hyperfine gradient distribution
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PD-0473: Comparing VMAT with IMRT and 3D-CRT for stereotactic body radiotherapy in early lung cancer
https://digitalcommons.wpi.edu/ourmutualfriend/1001/thumbnail.jp
A spatial column-store to triangulate the Netherlands on the fly
3D digital city models, important for urban planning, are currently constructed from massive point clouds obtained through airborne LiDAR (Light Detection and Ranging). They are semantically enriched with information obtained from auxiliary GIS data like Cadastral data which contains information about the boundaries of properties, road networks, rivers, lakes etc. Technical advances in the LiDAR data acquisition systems made possible the rapid acquisition of high resolution topographical information for an entire country. Such data sets are now reaching the trillion points barrier. To cope with this data deluge and provide up-to-date 3D digital city models on demand current geospatial management strategies should be re-thought. This work presents a column-oriented Spatial Database Management System which provides in-situ data access, effective data skipping, efficient spatial operations, and interactive data visualization. Its efficiency and scalability is demonstrated using a dense LiDAR scan of The Netherlands consisting of 640 billion points and the latest Cadastral information, and compared with PostGIS
Suppression of Zeeman Gradients by Nuclear Polarization in Double Quantum Dots
We use electric dipole spin resonance to measure dynamic nuclear polarization
in InAs nanowire quantum dots. The resonance shifts in frequency when the
system transitions between metastable high and low current states, indicating
the presence of nuclear polarization. We propose that the low and the high
current states correspond to different total Zeeman energy gradients between
the two quantum dots. In the low current state, dynamic nuclear polarization
efficiently compensates the Zeeman gradient due to the g-factor mismatch,
resulting in a suppressed total Zeeman gradient. We present a theoretical
model of electron-nuclear feedback that demonstrates a fixed point in nuclear
polarization for nearly equal Zeeman splittings in the two dots and predicts a
narrowed hyperfine gradient distribution
The use of learner-generated drawings in the development of music studentsâ teacher identities
Identity development is a continuous process framed within changing social contexts, and is particularly problematic for musicians and other artists whose work contradicts the mythologized image of the artist. The purpose of this article is to examine the professional growth of music students in relation to developing teacher identities. The article reports on the use of learner-generated drawings and journal reflections produced by music performance and education majors; in particular, the article probes studentsâ perceptions of teaching within a traditional career hierarchy that favours performance and artistic creation above all else. Whilst initial student drawings illustrated traditional images of the teacher as knowledge giver, these gave way to student-centred images in which students appeared to identify with teaching in new ways. The combination of textual and non-textual data provided insights that would not otherwise have been evident, and the consideration of âpossible selvesâ became a useful tool in the explorations of identity and career
LHCb Alignment Strategy
In this note, we review the alignment strategy for the LHCb detector. We discuss the internal alignment stategy for each subdetector and the alignment of each of the subdetectors relative to one another
Coping with loneliness: What do older adults suggest?
Objectives: A limited amount of information is available on how older adults cope with loneliness. Two ways of coping are distinguished here, i.e. active coping by improving relationships and regulative coping by lowering expectations about relationships. We explore how often older adults suggest these options to their lonely peers in various situations and to what extent individual resources influence their suggestions. Method: After introducing them to four vignettes of lonely individuals, discriminating with regard to age, partner status, and health, 1187 respondents aged 62 to 100 from the Longitudinal Aging Study Amsterdam were asked whether this loneliness can be alleviated by using various ways of coping. Results: In general, both ways of coping were often suggested. However, regression analyses revealed that active coping was suggested less often to people who are older, in poor health, or lonely and by older adults who were employed in midlife and have high self-esteem. Regulative coping was suggested more often to people who are older and by older adults with a low educational level and with low mastery. Conclusions: Coping with loneliness by actively removing the stressor is less often seen as an option for and by the people who could benefit most from it. This underlines the difficulty of combating loneliness
Predicting procedure duration of colorectal endoscopic submucosal dissection at Western endoscopy centers
Background and study aims Overcoming logistical obstacles for the implementation of colorectal endoscopic submucosal dissection (ESD) requires accurate prediction of procedure times. We aimed to evaluate existing and new prediction models for ESD duration.Patients and methods Records of all consecutive patients who underwent single, non-hybrid colorectal ESDs before 2020 at three Dutch centers were reviewed. The performance of an Eastern prediction model [GIE 2021;94(1):133â144] was assessed in the Dutch cohort. A prediction model for procedure duration was built using multivariable linear regression. The modelâs performance was validated using internal validation by bootstrap resampling, internal-external cross-validation and external validation in an independent Swedish ESD cohort.Results A total of 435 colorectal ESDs were analyzed (92% en bloc resections, mean duration 139 minutes, mean tumor size 39 mm). The performance of current unstandardized time scheduling practice was suboptimal (explained variance: R2=27%). We successfully validated the Eastern prediction model for colorectal ESD duration <60 minutes (c-statistic 0.70, 95% CI 0.62â0.77), but this model was limited due to dichotomization of the outcome and a relatively low frequency (14%) of ESDs completed <60 minutes in the Dutch centers. The model was more useful with a dichotomization cut-off of 120 minutes (c-statistic: 0.75; 88% and 17% of âeasyâ and âvery difficultâ ESDs completed <120 minutes, respectively). To predict ESD duration as continuous outcome, we developed and validated the six-variable cESD-TIME formula (https://cesdtimeformula.shinyapps.io/calculator/; optimism-corrected R2=61%; R2=66% after recalibration of the slope).Conclusions We provided two useful tools for predicting colorectal ESD duration at Western centers. Further improvements and validations are encouraged with potential local adaptation to optimize time planning
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