1,787 research outputs found
Generation of Hidden Optical-Polarization: Squeezing and Non-Classicality
A monochromatic double-mode coherent light endowed with orthogonally
polarized photons propagating collinearly is studied in Degenerate Parametric
Amplification. Generation of Hidden Optical- Polarized States is shown by
non-zero values of Index of Hidden Optical-Polarization. Squeezing in HOPS is
demonstrated by recognizing a Squeezing function. The Non-Classical feature of
HOPS is observed by 'degree of Hidden Optical-Polarization' which attains
non-classical value 'greater than unity'. The dynamical nature of Generation,
Squeezing and Non-Classicality are numerically presented.Comment: 14 pages and 02 figure
The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design
The ABCD twin study will elucidate the genetic and environmental contributions to a wide range of mental and physical health outcomes in children, including substance use, brain and behavioral development, and their interrelationship. Comparisons within and between monozygotic and dizygotic twin pairs, further powered by multiple assessments, provide information about genetic and environmental contributions to developmental associations, and enable stronger tests of causal hypotheses, than do comparisons involving unrelated children. Thus a sub-study of 800 pairs of same-sex twins was embedded within the overall Adolescent Brain and Cognitive Development (ABCD) design. The ABCD Twin Hub comprises four leading centers for twin research in Minnesota, Colorado, Virginia, and Missouri. Each site is enrolling 200 twin pairs, as well as singletons. The twins are recruited from registries of all twin births in each State during 2006–2008. Singletons at each site are recruited following the same school-based procedures as the rest of the ABCD study. This paper describes the background and rationale for the ABCD twin study, the ascertainment of twin pairs and implementation strategy at each site, and the details of the proposed analytic strategies to quantify genetic and environmental influences and test hypotheses critical to the aims of the ABCD study. Keywords: Twins, Heritability, Environment, Substance use, Brain structure, Brain functio
Collaborative Approach to the Creation of Open Textbooks: From Fundraising to Publishing
Open access textbook publishing initiatives not only provide libraries the opportunity to recast their longstanding mission to facilitate research and remove barriers to information but they also impact student affordability efforts. How can a library build a program that will meet the needs of students, faculty, and administrators? The answer lies in collaboration and sharing. In 2013, with the support of a Provost-backed initiative, Portland State University (PSU) Library developed an open textbook publishing program that works with faculty to create open textbooks specifically designed for a course. The publishing initiative, PDXOpen, has published 10 open textbooks with an additional 7 in production. PDXOpen has saved PSU Students over $85,000 and has been sustained through numerous collaborations and stakeholders including the Provost, Alumni Association and donors. Working with these varied stakeholders the Library has had the opportunity to work with PSU faculty and provide a platform to make open textbooks accessible to students. The presentation will focus on collaborative approaches to open textbook publishing efforts, and provide examples of how to communicate the value of open textbooks to influence varied stakeholders. Presenters will also review the process of working with faculty to create their open textbook projects, working with campus experts to support the program participants, and the continued development of open textbooks at PSU.
In addition the following insights and lessons learned will be discussed: Developing donor relationships Importance of peer-reviewers outside of the university Understanding author needs Difficulty of estimating cost and time to develop an open textbook Pursuing collaborative efforts for the development and publishing of open textbooks Supporting updates and edition
Cognitive Effort Avoidance in Veterans with Suicide Attempt Histories
Suicide attempts (SA) are increasing in the United States, especially in veterans. Discovering individual cognitive features of the subset of suicide ideators who attempt suicide is critical. Cognitive theories attribute SA to facile schema-based negative interpretations of environmental events. Over-general autobiographical memory and facile solutions in problem solving tasks in SA survivors suggest that aversion to expending cognitive effort may be a neurobehavioral marker of SA risk. In veterans receiving care for mood disorder, we compared cognitive effort discounting and evidence-gathering in a beads task between veterans with (SAHx+; n = 26) versus without (SAHx-; n = 22) a history of SA. Groups did not differ in depressed mood or in a proxy metric of premorbid intelligence. Compared to SAHx- participants, SAHx+ participants self-reported significantly more severe cognitive problems in most domains, and also eschewed choice to earn higher monetary reward if earning it required a slightly increased working memory (WM) demand relative to an easy WM task. There was no group difference, however, in extent of evidence-gathering before declaring a conclusion in a beads task. These preliminary data suggest that aversion to expenditure of cognitive effort, potentially as a component of cognitive difficulties, may be a marker for SA risk
Do skeletal cephalometric characteristics correlate with condylar volume, surface and shape? A 3D analysis
Positioning uncertainties for pediatric craniospinal irradiation and the impact of image guidance
The structure of cognition in 9 and 10 year-old children and associations with problem behaviors: Findings from the ABCD study\u27s baseline neurocognitive battery
The Adolescent Brain Cognitive Development (ABCD) study is poised to be the largest single-cohort long-term longitudinal study of neurodevelopment and child health in the United States. Baseline data on N= 4521 children aged 9-10 were released for public access on November 2, 2018. In this paper we performed principal component analyses of the neurocognitive assessments administered to the baseline sample. The neurocognitive battery included seven measures from the NIH Toolbox as well as five other tasks. We implemented a Bayesian Probabilistic Principal Components Analysis (BPPCA) model that incorporated nesting of subjects within families and within data collection sites. We extracted varimax-rotated component scores from a three-component model and associated these scores with parent-rated Child Behavior Checklist (CBCL) internalizing, externalizing, and stress reactivity. We found evidence for three broad components that encompass general cognitive ability, executive function, and learning/memory. These were significantly associated with CBCL scores in a differential manner but with small effect sizes. These findings set the stage for longitudinal analysis of neurocognitive and psychopathological data from the ABCD cohort as they age into the period of maximal adolescent risk-taking
Single donor ionization energies in a nanoscale CMOS channel
One consequence of the continued downwards scaling of transistors is the
reliance on only a few discrete atoms to dope the channel, and random
fluctuations of the number of these dopants is already a major issue in the
microelectonics industry. While single-dopant signatures have been observed at
low temperature, studying the impact of only one dopant up to room temperature
requires extremely small lengths. Here, we show that a single arsenic dopant
dramatically affects the off-state behavior of an advanced microelectronics
field effect transistor (FET) at room temperature. Furthermore, the ionization
energy of this dopant should be profoundly modified by the close proximity of
materials with a different dielectric constant than the host semiconductor. We
measure a strong enhancement, from 54meV to 108meV, of the ionization energy of
an arsenic atom located near the buried oxide. This enhancement is responsible
for the large current below threshold at room temperature and therefore
explains the large variability in these ultra-scaled transistors. The results
also suggest a path to incorporating quantum functionalities into silicon CMOS
devices through manipulation of single donor orbitals
Reliability and stability challenges in ABCD task fMRI data
Trait stability of measures is an essential requirement for individual differences research. Functional MRI has been increasingly used in studies that rely on the assumption of trait stability, such as attempts to relate task related brain activation to individual differences in behavior and psychopathology. However, recent research using adult samples has questioned the trait stability of task-fMRI measures, as assessed by test-retest correlations. To date, little is known about trait stability of task fMRI in children. Here, we examined within-session reliability and long-term stability of individual differences in task-fMRI measures using fMRI measures of brain activation provided by the adolescent brain cognitive development (ABCD) Study Release v4.0 as an individual\u27s average regional activity, using its tasks focused on reward processing, response inhibition, and working memory. We also evaluated the effects of factors potentially affecting reliability and stability. Reliability and stability (quantified as the ratio of non-scanner related stable variance to all variances) was poor in virtually all brain regions, with an average value of 0.088 and 0.072 for short term (within-session) reliability and long-term (between-session) stability, respectively, in regions of interest (ROIs) historically-recruited by the tasks. Only one reliability or stability value in ROIs exceeded the \u27poor\u27 cut-off of 0.4, and in fact rarely exceeded 0.2 (only 4.9%). Motion had a pronounced effect on estimated reliability/stability, with the lowest motion quartile of participants having a mean reliability/stability 2.5 times higher (albeit still \u27poor\u27) than the highest motion quartile. Poor reliability and stability of task-fMRI, particularly in children, diminishes potential utility of fMRI data due to a drastic reduction of effect sizes and, consequently, statistical power for the detection of brain-behavior associations. This essential issue urgently needs to be addressed through optimization of task design, scanning parameters, data acquisition protocols, preprocessing pipelines, and data denoising methods
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