Iowa Vocational Rehabilitation Services Biennial Report, 2011-2012

The division shall report biennially to the governor the condition of vocational rehabilitation within the state, designating the educational institutions, establishments, plants, factories, and other agencies in which training is being given, and include a detailed statement of expenditures of the state and federal funds in the rehabilitation of individuals with disabilities.

Iowa Vocational Rehabilitation Services Biennial Report, 2013-2014

The division shall report biennially to the governor the condition of vocational rehabilitation within the state, designating the educational institutions, establishments, plants, factories, and other agencies in which training is being given, and include a detailed statement of expenditures of the state and federal funds in the rehabilitation of individuals with disabilities.

Cross-frequency coupling in EEG revealed by adaptive oscillation tracking.

Introduction: Neuronal oscillations have been the focus of increasing interest in the neuroscientific community, in part because they have been considered as a possible integrating mechanism through which internal states can influence stimulus processing in a top-down way (Engel et al., 2001). Moreover, increasing evidence indicates that oscillations in different frequency bands interact with one other through coupling mechanisms (Jensen and Colgin, 2007). The existence and the importance of these cross-frequency couplings during various tasks have been verified by recent studies (Canolty et al., 2006; Lakatos et al., 2007). In this study, we measure the strength and directionality of two types of couplings - phase-amplitude couplings and phase-phase couplings - between various bands in EEG data recorded during an illusory contour experiment that were identified using a recently-proposed adaptive frequency tracking algorithm (Van Zaen et al., 2010). Methods: The data used in this study have been taken from a previously published study examining the spatiotemporal mechanisms of illusory contour processing (Murray et al., 2002). The EEG in the present study were from a subset of nine subjects. Each stimulus was composed of 'pac-man' inducers presented in two orientations: IC, when an illusory contour was present, and NC, when no contour could be detected. The signals recorded by the electrodes P2, P4, P6, PO4 and PO6 were averaged, and filtered into the following bands: 4-8Hz, 8-12Hz, 15-25Hz, 35-45Hz, 45-55Hz, 55-65Hz and 65-75Hz. An adaptive frequency tracking algorithm (Van Zaen et al., 2010) was then applied in each band in order to extract the main oscillation and estimate its frequency. This additional step ensures that clean phase information is obtained when taking the Hilbert transform. The frequency estimated by the tracker was averaged over sliding windows and then used to compare the two conditions. Two types of cross-frequency couplings were considered: phase-amplitude couplings and phase-phase couplings. Both types were measured with the phase locking value (PLV, Lachaux et al., 1999) over sliding windows. The phase-amplitude couplings were computed with the phase of the low frequency oscillation and the phase of the amplitude of the high frequency one. Different coupling coefficients were used when measuring phase-phase couplings in order to estimate different m:n synchronizations (4:3, 3:2, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1 and 9:1) and to take into account the frequency differences across bands. Moreover, the direction of coupling was estimated with a directionality index (Bahraminasab et al., 2008). Finally, the two conditions IC and NC were compared with ANOVAs with 'subject' as a random effect and 'condition' as a fixed effect. Before computing the statistical tests, the PLV values were transformed into approximately normal variables (Penny et al., 2008). Results: When comparing the mean estimated frequency across conditions, a significant difference was found only in the 4-8Hz band, such that the frequency within this band was significantly higher for IC than NC stimuli starting at ~250ms post-stimulus onset (Fig. 1; solid line shows IC and dashed line NC). Significant differences in phase-amplitude couplings were obtained only when the 4-8 Hz band was taken as the low frequency band. Moreover, in all significant situations, the coupling strength is higher for the NC than IC condition. An example of significant difference between conditions is shown in Fig. 2 for the phase-amplitude coupling between the 4-8Hz and 55-65Hz bands (p-value in top panel and mean PLV values in the bottom panel). A decrease in coupling strength was observed shortly after stimulus onset for both conditions and was greater for the condition IC. This phenomenon was observed with all other frequency bands. The results obtained for the phase-phase couplings were more complex. As for the phase-amplitude couplings, all significant differences were obtained when the 4-8Hz band was considered as the low frequency band. The stimulus condition exhibiting the higher coupling strength depended on the ratio of the coupling coefficients. When this ratio was small, the IC condition exhibited the higher phase-phase coupling strength. When this ratio was large, the NC condition exhibited the higher coupling strength. Fig. 3 shows the phase-phase couplings between the 4-8Hz and 35-45Hz bands for the coupling coefficient 6:1, and the coupling strength was significantly higher for the IC than NC condition. By contrast, for the coupling coefficient 9:1 the NC condition gave the higher coupling strength (Fig. 4). Control analyses verified that it is not a consequence of the frequency difference between the two conditions in the 4-8Hz band. The directionality measures indicated a transfer of information from the low frequency components towards the high frequency ones. Conclusions: Adaptive tracking is a feasible method for EEG analyses, revealing information both about stimulus-related differences and coupling patterns across frequencies. Theta oscillations play a central role in illusory shape processing and more generally in visual processing. The presence vs. absence of illusory shapes was paralleled by faster theta oscillations. Phase-amplitude couplings were decreased more for IC than NC and might be due to a resetting mechanism. The complex patterns in phase-phase coupling between theta and beta/gamma suggest that the contribution of these oscillations to visual binding and stimulus processing are not as straightforward as conventionally held. Causality analyses further suggest that theta oscillations drive beta/gamma oscillations (see also Schroeder and Lakatos, 2009). The present findings highlight the need for applying more sophisticated signal analyses in order to establish a fuller understanding of the functional role of neural oscillations.

Fifth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1908 to June 30, 1910

1908-1910 Iowa Library Commission Report made to the Governor of Iowa.

Ninth Report of the Iowa Library Commission for the Biennial Period July 1, 1916 to June 30, 1918

1916-1918 Iowa Library Commission Report made to the Governor of Iowa.

1920 Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1918 to June 30, 1920

1918-1920 Iowa Library Commission Report made to the Governor of Iowa.

Eleventh Report of the Iowa Library Commission for the Biennial Period July 1, 1920 to June 30, 1922

1920-1922 Iowa Library Commission Report made to the Governor of Iowa.

Twelfth Report of the Iowa Library Commission to the Governor of Iowa for the Biennial Period July 1, 1922 to June 30, 1924

1922-1924 Iowa Library Commission Report made to the Governor of Iowa.

Thirteenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1924 to June 30, 1926

1924-1926 Iowa Library Commission Report made to the Governor of Iowa.

Fourteenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 2926 to June 30, 1928

1926-1928 Iowa Library Commission Report made to the Governor of Iowa.

Fifteenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1928 to June 30, 1930 1928-1930

1928-1930 Iowa Library Commission Report made to the Governor of Iowa.

Sixteenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1930 to June 30, 1932

1930-1932 Iowa Library Commission Report made to the Governor of Iowa.

Seventeenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1, 1932 to June 30, 1934

1932-1934 Iowa Library Commission Report made to the Governor of Iowa.

Nineteenth Report of the Iowa Library Commission Made to the Governor of Iowa for the Biennial Period July 1,1936 to June 30, 1938

1936-1938 Iowa Library Commission Report made to the Governor of Iowa.

Quasi real-time Raman studies on the growth of Cu-In-S thin films

In this work annealing and growth of CuInS2 thin films is investigated with quasireal-time in situ Raman spectroscopy. During the annealing a shift of the Raman A1 mode towards lower wave numbers with increasing temperature is observed. A linear temperature dependence of the phonon branch of ¿2 cm¿1/100 K is evaluated. The investigation of the growth process (sulfurization of metallic precursors) with high surface sensitivity reveals the occurrence of phases which are not detected with bulk sensitive methods. This allows a detailed insight in the formation of the CuInS2 phases. Independent from stoichiometry and doping of the starting precursors the CuAu ordering of CuInS2 initially forms as the dominating ordering. The transformation of the CuAu ordering into the chalcopyrite one is, in contrast, strongly dependent on the precursor composition and requires high temperatures.