BACKGROUND High quality counseling of potential parents is needed in the process of disclosure to donor offspring, which is important for the child and for family relationships. We performed a search for facts to identify the role of counseling in couples undergoing gamete donation. METHODS We systematically searched Pubmed, EMBASE and Psychinfo. Studies were included if they reported on coun...

We study the impact of social influence on the performance of ads on social networks. Using data for several ads on Facebook for two different firms, we measure the impact of past connections on the click rate and endorsement rate of ads. We find that increase in the connections does not lead to an increase in the click performance and may even decrease the click performance. We also find that ...

By enabling connections between individuals, Social Networking Sites, such as Facebook, promise to create significant individual as well as social value. Encouraging connections between users is also crucial for service providers who increasingly rely on social advertising and viral marketing campaigns as important sources of their revenue. Consequently, understanding user’s network constructio...

According to a recently developed theory of wave propagation in marine sediments, the dispersion relationships for the phase speed and attenuation of the compressional and the shear wave depend on only three macroscopic physical variables: porosity, grain size, and depth in the sediment. The dispersion relations also involve three (real) parameters, assigned fixed values, representing microscop...

BACKGROUND Direct/ measurement of work activities is costly, so researchers need to distribute resources efficiently to elucidate the relationships between exposures and back injury. METHODS This study used data from full-shift electromyography (EMG; N=133) to develop three exposure metrics: mean, 90th percentile and cumulative EMG. For each metric, the components of variance were calculated ...

A light attenuation sensor system (LASS) for measurements in waters is described in this paper. The LASS records irradiance at multiple levels in the water column to provide a measure of the diffuse light attenuation coefficient which is strongly affected by suspended sediment. Dimensional analysis and geometric optical theory are used to relate the irradiance attenuation to sediment properties...

Photosynthesis-irradiance (P-I) characteristics of periphyton (microphytobenthos) have been considered primarily for entire assemblages. How P-I responses vary with mat thickness and with community composition has not been considered in detail. We used a combined approach of modeling, microscale determinations of photosynthetic rate and light attenuation, and whole-assemblage O2 flux measuremen...