Smoothing dynamic positron emission tomography time courses using functional principal components

A functional smoothing approach to the analysis of PET time course data is presented. By borrowing information across space and accounting for this pooling through the use of a nonparametric covariate adjustment, it is possible to smooth the PET time course data thus reducing the noise. A new model for functional data analysis, the Multiplicative Nonparametric Random Effects Model, is introduced to more accurately account for the variation in the data. A locally adaptive bandwidth choice helps to determine the correct amount of smoothing at each time point. This preprocessing step to smooth the data then allows Subsequent analysis by methods Such as Spectral Analysis to be substantially improved in terms of their mean squared error

Neuronal Mechanisms and Transformations Encoding Time-Varying Signals

Sensation in natural environments requires the analysis of time-varying signals. While previous work has uncovered how a signal’s temporal rate is represented by neurons in sensory cortex, in this issue of Neuron, new evidence from Gao et al. (2016) provides insights on the underlying mechanisms

Relativistic expansion of a magnetized fluid

We study semi-analytical time-dependent solutions of the relativistic magnetohydrodynamic (MHD) equations for the fields and the fluid emerging from a spherical source. We assume uniform expansion of the field and the fluid and a polytropic relation between the density and the pressure of the fluid. The expansion velocity is small near the base but approaches the speed of light at the light sphere where the flux terminates. We find self-consistent solutions for the density and the magnetic flux. The details of the solution depend on the ratio of the toroidal and the poloidal magnetic field, the ratio of the energy carried by the fluid and the electromagnetic field and the maximum velocity it reaches.Comment: 17 pages, 6 figures, accepted by Geophysical and Astrophysical Fluid Dynamic

Palladium(ii) complexes with chiral organoantimony(iii) ligands. Solution behaviour and solid state structures

The chiral compound (2-Me2NCH2C6H 4)PhSbCl (1) was obtained from (2-Me2NCH2C 6H4)Li and PhSbCl2 in 1:1 molar ratio, while (2-Me2NCH2C6H4)Mes2Sb (2) was prepared from (2-Me2NCH2C6H 4)SbCl2 and MesMgBr in 1:2 molar ratio. The compounds 1 and 2 were used to obtain the Pd(ii)/stibine complexes: [Me2NHCH 2C6H5]+[PdCl3SbCl(Ph) (C6H4CH2NMe2-2)-Sb]- (3) and [PdCl2SbMes2(C6H4CH 2NMe2-2)-N,Sb] (4). All the compounds were characterized by multinuclear NMR spectroscopy in solution, elemental analysis, mass spectrometry and single-crystal X-ray diffraction studies. In compounds 1-3 the coordination geometry around the antimony atom is pseudo-trigonal bipyramidal, while in compound 4 a tetrahedral geometry around the antimony atom is observed. Theoretical calculations at the DFT level on compounds 1-4 were used in order to gain insight into the nature of the coordinative bonds

Identifying geochemical hot moments and their controls on a contaminated river floodplain system using wavelet and entropy approaches

Geochemical hot moments are defined here as short periods of time that are associated with disproportionally high levels of concentrations (biogeochemically-driven or transport-related) relative to longer intervening time periods. We used entropy and wavelet techniques to identify temporal variability in geochemical constituents and their controls along three transects within a contaminated floodplain system near Rifle CO. Results indicated that transport-dominated hot moments drove overall geochemical processing in the contaminated groundwater and seep zones. These hot moments were associated with seasonal hydrologic variability (∼4 months) in the contaminated aquifer and with annual hydrologic cycle and residence times in the seep zone. Hot moments associated with a naturally reduced zone within the aquifer were found to be biogeochemically-driven, with a different dominant frequency (∼3 months) and no correlation to hydrologic or weather variations, in contrast to what is observed in other regions of the floodplain

Causal effect of plasminogen activator inhibitor type 1 on coronary heart disease

Background--Plasminogen activator inhibitor type 1 (PAI-1) plays an essential role in the fibrinolysis system and thrombosis. Population studies have reported that blood PAI-1 levels are associated with increased risk of coronary heart disease (CHD). However, it is unclear whether the association reflects a causal influence of PAI-1 on CHD risk. Methods and Results--To evaluate the association between PAI-1 and CHD, we applied a 3-step strategy. First, we investigated the observational association between PAI-1 and CHD incidence using a systematic review based on a literature search for PAI-1 and CHD studies. Second, we explored the causal association between PAI-1 and CHD using a Mendelian randomization approach using summary statistics from large genome-wide association studies. Finally, we explored the causal effect of PAI-1 on cardiovascular risk factors including metabolic and subclinical atherosclerosis measures. In the systematic meta-analysis, the highest quantile of blood PAI-1 level was associated with higher CHD risk comparing with the lowest quantile (odds ratio=2.17; 95% CI: 1.53, 3.07) in an age- and sex-adjusted model. The effect size was reduced in studies using a multivariable-adjusted model (odds ratio=1.46; 95% CI: 1.13, 1.88). The Mendelian randomization analyses suggested a causal effect of increased PAI-1 level on CHD risk (odds ratio=1.22 per unit increase of log-transformed PAI-1; 95% CI: 1.01, 1.47). In addition, we also detected a causal effect of PAI-1 on elevating blood glucose and high-density lipoprotein cholesterol. Conclusions--Our study indicates a causal effect of elevated PAI-1 level on CHD risk, which may be mediated by glucose dysfunction.</p

A grounded theory of music use in the psychological preparation of academy soccer players

This is the author accepted manuscript. The final version is available from American Psychological Association via the DOI in this record. The main objectives of the present study are (a) to examine soccer players’ use of music to psychologically prepare for performance and (b) to present a grounded theory to illuminate this phenomenon. Thirty-four academy soccer players (Mage = 17.9 years, SD = 1.6 years) were selected from a U.K. Premier League soccer club. Individual- and group-based questionnaires, reflective journals, and interviews were administered. Corbin and Strauss’s (2015) variant of grounded theory was adopted, which is underpinned by pragmatism and symbolic interactionism. Data were analyzed using open, axial, and selective coding. Moreover, the data were continually compared with previous literature to verify methodological coherence, propose new methods, and develop a substantive grounded theory model. The findings document the use of music as a stimulant and regulator of emotion prior to performance, as well as its propensity to develop shared meanings and contribute to a sense of group identity. The analysis brought to light personal-, group-, and task-related factors that moderate the influence of music on the psychological state of young soccer players. A unique finding to emerge was the degree to which the music preferences of senior players were readily accepted by junior players. The present study provides evidence of the role that naturalistic research can play in fathoming and harnessing the emotive and encultured power of music within the social spheres of elite team sports. All emergent concepts can be used as a template to guide soccer players and practitioners in the use of music and to frame future research efforts.Coordination for the Improvement of Higher Education Personnel (CAPES), Brazi

Security of distributed-phase-reference quantum key distribution

Distributed-phase-reference quantum key distribution stands out for its easy implementation with present day technology. Since many years, a full security proof of these schemes in a realistic setting has been elusive. For the first time, we solve this long standing problem and present a generic method to prove the security of such protocols against general attacks. To illustrate our result we provide lower bounds on the key generation rate of a variant of the coherent-one-way quantum key distribution protocol. In contrast to standard predictions, it appears to scale quadratically with the system transmittance.Comment: 4 pages + appendix, 4 figure

Triumph Over Tragedy, Second Edition: A Curriculum for Extension Professionals Responding to Disasters and Terrorism

We describe Triumph Over Tragedy, Second Edition: A Community Response to Managing Trauma in Times of Disaster and Terrorism, a curriculum designed to assist Extension professionals and other community stakeholders in helping their communities prepare for, and respond to, trauma associated with natural and human-made disasters. In the post-September 11, 2001 environment, it is imperative that community professionals become involved in planning for the psychological impact of these events