background: the increasing number of cesarean section is a great concern in many countries. in iran cesarean section rate has been steadily rising from 35% in 2000 to 40% in 2005. preferences for cesarean are often associated with some factors. objective: to investigate factors associated with preference for cesarean delivery, with special emphasis on pregnant women’s preferences in first pregn...

We extend Duration Calculus to a logic which allows description of Discrete Processes where several steps of computation can occur at the same time point. The resulting logic is called Duration Calculus of Weakly Monotonic Time (WDC). It allows effects such as true synchrony and digitisation to be modelled. As an example of this, we formulate a novel semantics of Timed CSP assuming that the com...

Effects of stimulus duration and inter-letter spacing were studied in a letter-in-string identification paradigm. Participants were shown strings of 5 random consonants (e.g., PGKDM) centered on fixation and were asked to identify the letter that had appeared at a post-cued location. Stimulus duration was manipulated in Experiment 1 (13 ms-91 ms), and inter-letter spacing manipulated in Experim...

For focused pulses of light in isotropic nonlinear media, third-harmonic generation can be strongly affected by group-velocity mismatch between the fundamental and third-harmonic. There is a characteristic time determined by the group-velocity mismatch and the Rayleigh range of the focused pulse. The dynamics depend on two dimensionless quantities, namely the ratio of the characteristic time to...

We efficiently extract an ultraviolet femtosecond pulse train of milliwatt average power and 100 MHz repetition rate from a colliding pulse mode-locked dye laser by intracavity frequency doubling in KDP. The ultraviolet and visible outputs, which are comparable in power and pulse duration, are perfect synchronized with each

We consider an interpretation of monadic second-order logic of order in the continuous time structure of nitely variable signals and show the decidability of monadic logic in this structure. The expressive power of monadic logic is illustrated by providing a straightforward meaning preserving translation into monadic logic of three typical continuous time speciication formalism: Temporal Logic ...

The challenge in visualizing fast microscale fluid motion phenomena is to record high-quality images free of motion-blur. Here, we present an illumination technique based on laser-induced fluorescence which delivers high-intensity light pulses of 7 ns. The light source consists of a Q-switched Nd:YAG laser and a laser dye solution incorporated into a total internal reflection lens, resulting in...