The present study was performed to determine whether or not spontaneous K-complexes are induced by sensory stimuli. In the first part of the present study, sound stimuli were prescribed during sleep in 7 healthy, young, adult subjects. EEG segments in stage 2 sleep were averaged separately according to the presence or absence of an evoked K-complex appearing after each stimulus. The sound stimu...

We propose and experimentally demonstrate a scalable and reconfigurable optical scheme to generate high order UWB pulses. Firstly, various ultra wideband doublets are created through a process of phase-to-intensity conversion by means of a phase modulation and a dispersive media. In a second stage, doublets are combined in an optical processing unit that allows the reconfiguration of UWB high o...

We apply a copula-GARCH approach to modeling the joint distribution of excess returns of four major assets: one year and ten year Treasury bonds and S&P 500 and Nasdaq indices. We try three approaches in building the multidimensional copula for the dependence structure of multiple variables: (1) n-dimensional normal copula and n-dimensional Student’s t copula, (2) hierarchical Archimedean copul...

This is a review paper in which different definitions of achievement are analyzed and different possibilities for test construction are explored. A first characterization of achievement is accomplished through the analysis of construct representation. From this perspective, the behavioral approach focuses more on the end result, whereas the cognitive approach is more process centered. In a seco...

OBJECTIVE To describe the association between provider communication and actual maternal pushing behavior in second-stage labor and to test differences in length of second stage and total maternal pushing time by maternal pushing behavior. DESIGN Descriptive. SETTING Midwest hospital birth unit. PARTICIPANTS Twenty primigravidas who gave birth vaginally. INTERVENTION Type of provider co...

The purpose of this study was to explore the interaction between achromatic information and chromatic information in a visual search task. It is widely accepted that signals in second stage color opponent mechanisms vary with both the luminance and chromaticity of a stimulus. However, detection experiments suggest a large degree of independence between chromatic thresholds and achromatic thresh...

This paper examines the dispersion of fertility across age and time which has rarely been studied. Using data from the Human Fertility Database, we examine fertility age schedules by looking at standard deviations in age at first births in European countries at different stages of fertility postponement. The standard deviation at first birth remained overall constant during the start of fertili...

The evolutionary puzzle of cooperation describes situations where cooperators provide a fitness benefit to other individuals at some cost to themselves. Under Darwinian selection, the evolution of cooperation is a conundrum, whereas non-cooperation (or defection) is not. In the absence of supporting mechanisms, cooperators perform poorly and decrease in abundance. Evolutionary game theory provi...

Thresholds for detecting changes in color are raised following viewing a field sinusoidally modulated in color over time. This effect is highly selective. For example, thresholds for detecting reddish and greenish changes from white are raised following viewing a field varying in a reddish-greenish direction, but not after viewing one varying in a yellowish-bluish direction. Similarly threshold...

The present paradigm in cosmology is the usual Big-Bang Cosmology in which two stages of accelerated expansion are incorporated: the inflationary phase in the very early universe which produces the classical inhomogeneities observed in the universe, and a second stage of acceleration at the present time as the latest Supernovae observations seem to imply. Both stages could be produced by a scal...