The techniques of cryopreservation let embryos which cannot be immediately transferred to the patient be stored for future use. The first successful pregnancy after transfer of cryopreserved human embryos was described in 1983 by Trounson et al. and the first birth after cryopreservation was later reported in 1984 by Zeilmaker et al.). The technique has rapidly been applied in most in-vitro fer...

Despite a fainter Sun, the surface of the early Earth was mostly ice-free. Proposed solutions to this so-called ”faint young Sun problem” have usually involved higher amounts of greenhouse gases than present in the modern-day atmosphere. However, geological evidence seemed to indicate that the atmospheric CO2 concentrations during the Archaean and Proterozoic were far too low to keep the surfac...

We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered ...

since the beginning of the arab spring, scholars in different fields around the world have studied it, exploiting various approaches. one of these approaches is the cultural change in which survival and self-expression values are analysed. this approach is discussed in the present paper. given that collective actions in every country are in line with its cultural values and cultural changes, th...