Statistical learning for the analysis of multimodal sleep in older men

Introduction: Sleep is essential for human development and maintaining physical and mental health. Sleep disturbances have long been known to be associated with mental illness, metabolic, neurological or other systems diseases. Knowing what factors are associated with sleep quality and sleep-wake homeostasis is important for the study of sleep disorders and may potentially inform new treatment strategies to preserve patients' normal sleep-wake cycle. The present study aims to identify what actigraphic measures, self-reported sleep variables, and other chronic diseases, medications are related to the percentage of slow-wave sleep and delta power spectra in older men. Method: Categorical variables are summarized using frequencies and percentages. For continuous variables, means and standard deviations are computed, and distributions are displayed in histograms. Possible correlations among variables are examined by a matrix of scatterplots and Pearson correlation coefficients. The LASSO is used for feature selection in multiple linear regression models and multiple imputation used to overcome missing data. Results: The past month sleep hours (β=0.0896, p<0.05), kidney diseases (β=0.161, p<0.05) and oral corticosteroids (β=0.148, p<0.05) are significantly positively associated with percentage of deep sleep, while sleep apnea severity (β=-0.0043, p<0.001), age ( = -0.0042, p<0.01), Benzodiazepine use ( -0.155, p<0.001), NSAIDS use (β=-0.0418, p<0.05), and race(β=-0.0476, p<0.01) are negatively associated when controlling other variables’ effect. Cognitive function (β=0.0015, p<0.001), and oral corticosteroids (β=0.0733, p<0.01) are positively related to delta power, while sleep apnea severity (β=-0.0011, p<0.001), age ( = -0.0013, p<0.05), mean sleep minutes (-0.0002, p<0.001) , BMI (-0.031, p<0.001), Diabetes (β=-0.0404, p<0.001), Benzodiazepine use ( -0.061, p<0.001), and the consumption of alcoholic beverages (β=-0.0125, p<0.05) are negatively related to delta power when controlling other covariates. Conclusions: Our study suggested several factors are either positively or negatively associated with the percentage of deep sleep and delta power. Most of the factors affect the percentage of slow-wave sleep and delta power in the same direction. Public Health Significance: These analyses may provide important messages for future study and potential medical interventions application

Prompt and non-prompt charm baryons with ALICE

Recent measurements of prompt charm-baryon production at midrapidity in pp and p--Pb collisions show baryon-to-meson yield ratios significantly higher than those in $\rm e^+e^-$ collisions, suggesting that the charm fragmentation is not universal across different collision systems. Thus, more precise and broader measurements of prompt charm-baryon production are crucial to study the charm quark hadronization in a partonic-rich environment like the one produced in pp collisions at the LHC energies. Prompt charm baryon-to-meson yield ratios in proton--nucleus collisions provide important information about possible additional modification of hadronization mechanisms, on cold nuclear matter effects, and on the possible presence of collective effects that could modify the production of heavy-flavor hadrons. The non-prompt charm-hadron production can provide information about the beauty sector and can be used to study flavor dependence of heavy-quark hadronization. In this contribution, the most recent results on prompt and non-prompt charm-hadron yield ratios in pp and p--Pb collisions and on charm fragmentation fractions and charm production cross section at midrapidity per unit of rapidity measured by ALICE are discussed.Comment: Proceedings of 41st International Conference on High Energy Physics (ICHEP2022), 06 - 13 July, 2022. 6 pages, 4 figure

Quantile regression in partially linear varying coefficient models

Semiparametric models are often considered for analyzing longitudinal data for a good balance between flexibility and parsimony. In this paper, we study a class of marginal partially linear quantile models with possibly varying coefficients. The functional coefficients are estimated by basis function approximations. The estimation procedure is easy to implement, and it requires no specification of the error distributions. The asymptotic properties of the proposed estimators are established for the varying coefficients as well as for the constant coefficients. We develop rank score tests for hypotheses on the coefficients, including the hypotheses on the constancy of a subset of the varying coefficients. Hypothesis testing of this type is theoretically challenging, as the dimensions of the parameter spaces under both the null and the alternative hypotheses are growing with the sample size. We assess the finite sample performance of the proposed method by Monte Carlo simulation studies, and demonstrate its value by the analysis of an AIDS data set, where the modeling of quantiles provides more comprehensive information than the usual least squares approach.Comment: Published in at http://dx.doi.org/10.1214/09-AOS695 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Hadronization studies at the LHC with ALICE

Studies of the production of heavy-flavour baryons are of prominent importance to investigate hadronization mechanisms at the LHC, in particular through the study of the evolution of the baryon-over-meson production ratio. Measurements performed in pp and p--Pb collisions at the LHC have revealed unexpected features, qualitatively similar to what was observed in heavy-ion collisions and, in the charm sector, not in line with the expectations based on previous measurements from $\rm e^+e^-$ colliders and in ep collisions. These results suggest that charmed baryon formation might not be universal and that the baryon-over-meson ratio depends on the collision system or multiplicity. A review of ALICE measurements of charmed baryons, including $\rm \Lambda_c^+/D^0$ as a function of charged-particle multiplicity in pp, p--Pb and Pb--Pb collisions, $\rm \Sigma_c^{0, +, ++}/D^0$ and $\rm \Xi_c^{0, +}/D^0$ as a function of $p_{\rm T}$ in pp collisions and $\rm \Gamma(\Xi_c^0\rightarrow\Xi^-e^+\nu_e)/\Gamma(\Xi_c^0\rightarrow\Xi^-\pi^+)$, will be presented. Comparison to phenomenological models will be also discussed. Emphasis will be given to the discussion of the impact of these studies on the understanding of hadronization processes.Comment: Proceedings of 40th International Conference on High Energy physics, July 28 - August 6, 2020. 6 pages, 3 figure

Characterizing AGB stars in Wide-field Infrared Survey Explorer (WISE) bands

Since asymptotic giant branch (AGB) stars are bright and extended infrared objects, most Galactic AGB stars saturate the Wide-field Infrared Survey Explorer (WISE) detectors and therefore the WISE magnitudes that are restored by applying point-spread-function fitting need to be verified. Statistical properties of circumstellar envelopes around AGB stars are discussed on the basis of a WISE AGB catalog verified in this way. We cross-matched an AGB star sample with the WISE All-Sky Source Catalog and the Two Mircon All Sky Survey catalog. Infrared Space Observatory (ISO) spectra of a subsample of WISE AGB stars were also exploited. The dust radiation transfer code DUSTY was used to help predict the magnitudes in the W1 and W2 bands, the two WISE bands most affected by saturation, for calibration purpose, and to provide physical parameters of the AGB sample stars for analysis. DUSTY is verified against the ISO spectra to be a good tool to reproduce the spectral energy distributions of these AGB stars. Systematic magnitude-dependent offsets have been identified in WISE W1 and W2 magnitudes of the saturated AGB stars, and empirical calibration formulas are obtained for them on the basis of 1877 (W1) and 1558 (W2) AGB stars that are successfully fit with DUSTY. According to the calibration formulae, the corrections for W1 at 5 mag and W2 at 4 mag are $-0.383$ and 0.217 mag, respectively. In total, we calibrated the W1/W2 magnitudes of 2390/2021 AGB stars. The model parameters from the DUSTY and the calibrated WISE W1 and W2 magnitudes are used to discuss the behavior of the WISE color-color diagrams of AGB stars. The model parameters also reveal that O-rich AGB stars with opaque circumstellar envelopes are much rarer than opaque C-rich AGB stars toward the anti-Galactic center direction, which we attribute to the metallicity gradient of our Galaxy.Comment: 9 pages in two column format, 7 figures, accepted for publication in A&

Correlation effects in the iron pnictides

One of the central questions about the iron pnictides concerns the extent to which their electrons are strongly correlated. Here we address this issue through the phenomenology of the charge transport and dynamics, single-electron excitation spectrum, and magnetic ordering and dynamics. We outline the evidence that the parent compounds, while metallic, have electron interactions that are sufficiently strong to produce incipient Mott physics. In other words, in terms of the strength of electron correlations compared to the kinetic energy, the iron pnictides are closer to intermediately-coupled systems lying at the boundary between itinerancy and localization, such as V2O3 or Se-doped NiS2, rather than to simple antiferromagnetic metals like Cr. This level of electronic correlations produces a new small parameter for controlled theoretical analyses, namely the fraction of the single-electron spectral weight that lies in the coherent part of the excitation spectrum. Using this expansion parameter, we construct the effective low-energy Hamiltonian and discuss its implications for the magnetic order and magnetic quantum criticality. Finally, this approach sharpens the notion of magnetic frustration for such a metallic system, and brings about a multiband matrix t-J1-J2 model for the carrier-doped iron pnictides.Comment: 14 pages, 2 figures, discussions on several points expanded, published in the Focus Issue on Iron-Based Superconductor

Heavy surface state in a possible topological Kondo insulator: Magneto-thermoelectric transport on the (011)-plane of SmB6_6

Motivated by the high sensitivity to Fermi surface topology and scattering mechanisms in magneto-thermoelectric transport, we have measured the thermopower and Nernst effect on the (011)-plane of the proposed topological Kondo insulator SmB$_6$. These experiments, together with electrical resistivity and Hall effect measurements, demonstrate that the (011)-plane also harbors a metallic surface with the effective mass in the order of 10-10$^2$ $m_0$. The surface and bulk conductances are well distinguished in these measurements and are categorized into metallic and non-degenerate semiconducting regimes, respectively. Electronic correlations play an important role in enhancing scattering and also contribute to the heavy surface state.Comment: 4 figures, 1 tabl

Compound Control of Electromagnetic Linear Actuator Based on Fuzzy Switching

Due to the motion control system of electromagnetic linear actuator (EMLA) is a nonlinear system with poor controllability, single control strategy has been difficult to meet the requirements of its control. A compound control strategy based on inverse system control (ISC) and proportional-integral (PI) is designed in this paper. Switching between two algorithms, which is based on the fuzzy rules, prevents the control algorithm to jitter and jump. System model is build under Matlab/Simulink to do simulation analysis. The designed controller is integrated into the system simulation model and the system software of digital signal processor (DSP) controller. Simulation and test results show that the compound control strategy using fuzzy switching rules achieves the smooth transition of two control algorithms, and the goal of any position location, and continuous adjustment in 0~4mm lift. Positioning accuracy is up to ± 0.02mm, while the response time is less than 10ms

Secure CrsMgr: a course manager system

Internet was developed for computers to be interconnected easily and hence allow them to interchange information. One of the early use of the internet was for email communications and file transfers. The web was developed to make the sharing of information much more convenient. However, the technology for protecting data when interaction is allowed was developed piecemeal and many web applications where user communicate using the web form based interface with a server and databases are exposed to various threats including malicious script. Moreover, companies and malicious users use trackers to observe and record the user actions. In this project we address these problems in connection with course manager system(CrsMgr) which is used currently to manage typical university courses; it includes features for posting notes, tutorials, assignments, projects, create and maintain student groups, provide facility for group peer evaluation, on-line quizzes, and grading. The technique used to enhance the security based on using filtration layer and prepared-execute layer to make CrsMgr secure. The goal of filtration layer is to catch malicious user input based on suspect key words; The goal of prepared-execute layer is to invalidate malicious input. The implementation of this feature uses mysqli, a PHP extension for secure database access. We have also developed an experimental browser which prevents user tracking and saves bandwidth by disallowing third party contents. The latter uses two techniques: filtration and user agent faking. Filtration is to check every resource Uniform Resource Identifier(URL) before making a request to load it, and not loading any target URL if it is determined to be a third party. The third party determination policy is configured by the user. The browser also provides user agent faking which is a feature that allows masquerading the browser and platform information with random information. The browser provides a simple user interface that allow user to verify the third party content on a web page and stop using a simple switch metaphor