A Bayesian Heteroscedastic GLM with Application to fMRI Data with Motion Spikes

We propose a voxel-wise general linear model with autoregressive noise and heteroscedastic noise innovations (GLMH) for analyzing functional magnetic resonance imaging (fMRI) data. The model is analyzed from a Bayesian perspective and has the benefit of automatically down-weighting time points close to motion spikes in a data-driven manner. We develop a highly efficient Markov Chain Monte Carlo (MCMC) algorithm that allows for Bayesian variable selection among the regressors to model both the mean (i.e., the design matrix) and variance. This makes it possible to include a broad range of explanatory variables in both the mean and variance (e.g., time trends, activation stimuli, head motion parameters and their temporal derivatives), and to compute the posterior probability of inclusion from the MCMC output. Variable selection is also applied to the lags in the autoregressive noise process, making it possible to infer the lag order from the data simultaneously with all other model parameters. We use both simulated data and real fMRI data from OpenfMRI to illustrate the importance of proper modeling of heteroscedasticity in fMRI data analysis. Our results show that the GLMH tends to detect more brain activity, compared to its homoscedastic counterpart, by allowing the variance to change over time depending on the degree of head motion

The Relationships Among Competitiveness, Age and Ability In Distance Runners

The purpose of this study was to examine relationships suggested by general achievement motivation literature and the popular literature in sport using the Sport Orientation Questionnaire (SOQ). The current study examined if faster runners are more competitive than slower runners, if older athletes were less competitive than younger athletes, and if faster runners were more goal oriented than slower runners. Distance runners (n=80), ranging from 10 to 61 years old completed race packets containing a cover letter, consent forms, the SOQ and a demographic questionnaire. Runners averaged 32.9 years of age and reported levels of competitiveness and goal orientation consistent with previous research. Results indicated that competitiveness and age were negatively related (r = -.44, p \u3c 001) and competitiveness and personal best times for all race distances were positively associated (r = .28, p \u3c .05 to .33, p \u3c .01). Ability and goal orientation were unrelated. In conclusion, both ability and age, in addition to a variety of significant social and cognitive correlates, may contribute to the development and decline of competitiveness. Future research should examine the way that competitiveness and related cognitions develop and wane over the life span

Factor Structure of the Athletic Identity Measurement Scale With Athletes With Disabilities

Individuals who perceive themselves as athletes are thought to have self-schemas composed of, in part, an athletic identity (Brewer, Van Raalte, & Linder, 1993). The recent development of the Athletic Identity Measurement Scale (AIMS) has allowed sport psychology researchers to assess athletic identity. Research with adolescent athletes with disabilities has suggested that the AIMS is composed of 4 factors (Martin, Mushett, & Eklund, 1994). The purpose of the current study was to further examine the psychometric properties of the AIMS. Seventy-eight international swimmers (34 females, 44 males) with disabilities, ranging in age from 12 to 44 (M = 23.4 years), participated in the present study. Using structural equation modeling procedures, a confirmatory factor analysis determined that the data fit the 4-factor model specified in the Martin et al. (1994) study, thus providing support for the multidimensionality of the AIMS

Using Crop Phenology to Assess Changes in Cultivated Land after the Anfal Genocide in Iraqi Kurdistan

Ponencias, comunicaciones y pósters presentados en el 17th AGILE Conference on Geographic Information Science "Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.The Anfal genocide campaign, carried out by the Iraqi government against the Kurdish population in 1988, has been reported to have severe consequences for agriculture and food security by causing large scale land abandonment. This study uses Landsat satellite data to detect agricultural changes that can be attributed to the Anfal genocide. Cultivated land were distinguished from other land cover types by focusing on crop phenology. Initial results show a strong decrease in cultivated land in the years after the genocide, especially in the areas that were targeted by the genocide campaign

Vibrational Study of 13C-enriched C60 Crystals

The infrared (IR) spectrum of solid C60 exhibits many weak vibrational modes. Symmetry breaking due to 13C isotopes provides a possible route for optically activating IR-silent vibrational modes. Experimental spectra and a semi-empirical theory on natural abundance and 13C-enriched single crystals of C60 are presented. By comparing the experimental results with the theoretical results, we exclude this isotopic activation mechanism from the explanation for weakly active fundamentals in the spectra.Comment: Accepted for Phys. Rev. B, typeset in REVTEX v3.0 in LaTeX. Postscript file including figures is available at http://insti.physics.sunysb.edu/~mmartin/papers/c13twocol2.ps File with figures will be e-mailed by reques

Insulating and Conducting Phases of RbC60

Optical measurements were performed on thin films of Rb$_{x}$C$_{60}$, identified by X-ray diffraction as mostly $x=1$ material. The samples were subjected to various heat treatments, including quenching and slow cooling from 400K. The dramatic increase in the transmission of the quenched samples, and the relaxation towards the transmission observed in slow cooled samples provides direct evidence for the existence of a metastable insulating phase. Slow cooling results in a phase transition between two electrically conducting phases.Comment: Minor revisions. Submitted to PRB, RevTeX 3.0 file, 2 postscript figures included, ir_dop

How to find an attractive solution to the liar paradox

The general thesis of this paper is that metasemantic theories can play a central role in determining the correct solution to the liar paradox. I argue for the thesis by providing a specific example. I show how Lewis’s reference-magnetic metasemantic theory may decide between two of the most influential solutions to the liar paradox: Kripke’s minimal fixed point theory of truth and Gupta and Belnap’s revision theory of truth. In particular, I suggest that Lewis’s metasemantic theory favours Kripke’s solution to the paradox over Gupta and Belnap’s. I then sketch how other standard criteria for assessing solutions to the liar paradox, such as whether a solution faces a so-called revenge paradox, fit into this picture. While the discussion of the specific example is itself important, the underlying lesson is that we have an unused strategy for resolving one of the hardest problems in philosophy

Factor Structure and Construct Validity of the Worker Role Self-Assessment (WRS) When Used for People With Psychiatric Disabilities in Sweden

A self-report instrument assessing work-related factors among people with psychiatric disabilities would be useful when trying to match possible employment or prevocational opportunities with people’s desires and capacities. The aim of this study was to explore the factor structure, internal consistency, and construct and criterion validity of the Worker Role Self-Assessment (WRS) in this group as well as possible floor and ceiling effects. The participants were 283 clients from day centers for people with psychiatric disabilities and from outpatient units for people with psychosis. They completed the WRS and instruments selected to assess construct validity in terms of convergent (motivation for work and current activity level as reference variables) and discriminant validity (quality of life and self-rated health as reference variables). Two factors were identified, one tapping beliefs in a future worker role and one reflecting current capacities and routines. The internal consistency for the scale as a whole was good at 0.84. The factor reflecting a future worker role correlated as expected with the reference variables used to assess convergent and discriminant validity, whereas current capacities and routines showed a moderate association with quality of life and self-rated health, assumed to indicate discriminant validity. Criterion validity was shown in that those who had recent work experiences scored higher than the others on WRS. No floor or ceiling effects were identified. The findings indicate acceptable psychometric properties of the WRS. Further development is still warranted, however; the factor solution needs to be replicated and the construct validity should be further established

Весовые соотношения тимуса и надпочечников у антенатально погибших плодов

ТИМУСНАДПОЧЕЧНИКИтимомегалиядети первого года жизнидети раннего возрастаМЛАДЕНЕЦ, СМЕРТНОСТЬЭНДОКРИННОЙ СИСТЕМЫ БОЛЕЗНИСМЕРТНОСТЬ ДЕТСКАЯсиндром внезапной детской смерт