Piezoelectric transducers for the measurement of rapidly alternating and acoustic pressures

The characteristics of piezoelectric transducers developed at the Scientific-Research Institute of Physical Measurements (NIIFI) are described. The article is taken from a paper presented at the International Scientific-Practical Conference on Piezoelectric Drives and Sensors in the city of Obninsk in January, 1993.Translated from Izmeritel'naya Tekhnika, No. 6, pp. 52–54, June, 1994.     

Nitric oxide regulates cell proliferation during Drosophila development

Cell division and subsequent programmed cell death in imaginal discs of Drosophila larvae determine the final size of organs and structures of the adult fly. We show here that nitric oxide (NO) is involved in controlling the size of body structures during Drosophila development. We have found that NO synthase (NOS) is expressed at high levels in developing imaginal discs. Inhibition of NOS in larvae causes hypertrophy of organs and their segments in adult flies, whereas ectopic expression of NOS in larvae has the opposite effect. Blocking apoptosis in eye imaginal discs unmasks surplus cell proliferation and results in an increase in the number of ommatidia and component cells of individual ommatidia. These results argue that NO acts as an antiproliferative agent during Drosophila development, controlling the balance between cell proliferation and cell differentiation.     

Mass transfer in porous injection of an inert gas into a liquid

Measurements are reported on mass-transfer coefficients for a liquid containing a porous body through which an inert gas is injected. The data are compared with measurements on heat transfer on porous injection and on boiling.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 3, pp. 410–414, September, 1986.