A method of propagating rotavirus in vitro which comprises growing the virus in cell cultures susceptible to the virus in the presence of a serum-free medium containing a proteolytic enzyme. Such a method promotes the growth of virus in tissue culture, thus providing large quantities of antigen for immunization and for use in diagnostic tests.

A propagator for the cultivation of plants in a controlled environment comprising upper and lower elongate containers having a common perforated wall, a plurality of plant seeds supported in spaced relation by or adjacent the common wall, means for injecting liquid in the form of vapor or droplets into an end of each of the elongate containers and means for maintaining a pressure in the elongate containers greater than atmospheric pressure.

A propagation primer containing a primer charge having a composition comprising, by weight, approximately: 40-60 percent of barium nitrate 10-20 percent of an aluminum-magnesium alloy 5-20 percent of lead dioxide 6-10 percent of zirconium hydride, and 1-5 percent of boron The composition is substantially insensitive to friction and shock. For propagation over larger distances, additional specific primer compositions may be employed.

Yeast is propagated in the presence of an effective amount of a nonnutritive ionizable salt sufficient to impart to the yeast superior leavening activity in sweet dough. Examples of nonnutritive salts are NaCl, Na.sub.2 So.sub.4, NaBr, Na.sub.2 Co.sub.3, Na acetate, and SrC1.sub.2.

A propagation tray configured to receive a plurality of seedlings or root cuttings comprising a tray member having an outer peripheral skirt formed about the periphery thereof and a plurality of propagation cells each having an upper centrally disposed aperture formed in the upper portion thereof inwardly of the outer peripheral skirt to receive a growing media and seedlings or root cuttings therein, a lower centrally disposed drainage aperture formed in the lower portion thereof and a growing m...

A propagation tray configured to receive a plurality of seedlings or the like comprising a tray member having an outer peripheral ledge formed about the periphery thereof and plurality of elongated frustum conical propagation cells each having a centrally disposed aperture formed in the upper portion thereof to receive individual seedlings formed inwardly of the outer peripheral ledge and a drainage aperture and cell support surface formed on the lower portion thereof such that the seedlings dis...

A method of cultivating a plant is disclosed which meets certain aesthetic and other requirements. A plant (8) is stripped of any unwanted growth from its stem (9) leaving the upper foliage (10) in place. The thus stripped stem (9) is then passed through the full length slot (2) of a first sleeve (1) to retain the stem (9) within the sleeve (1). A hollow frusto-conical retainer (3) is then positioned with its smaller end in communication with the upper end of the sleeve (1), the upper foliage (1...

Bubble-to-bubble interaction in a magnetic bubble domain memory is reduced by a notch provided in the outer edge of the replicator of the bubble memory device. The notch serves to slow down the movement of the bubble around the replicator or U-turn element so that it does not elongate under a critical phase of the in-plane field.

This transformer (9) is formed by a waveguide, of approximately elliptical cross-section, and with increasing eccentricity (e) along the axis (z) of the transformer. This transformer (9) is connected on one side to the cavity (1) of a gyrotron (11) and on the other side to a section of guide (13) having the same cross-section as the final cross-section of the transformer and of which the cross-section is constant along the axis (z) of the transformer. The transformer receives from the gyrotron c...

A propagation delay generator is provided for controlling the duration of a bubble generate waveform of a bubble memory system. A first means is responsive to a digital input signal and provides an initializing signal to a current source. A capacitor is charged, responsive to an R-C time constant, by an increased voltage level prompted by the initializing signal. A second means is responsive to the charging signal in excess of that required to charge the capacitor. The second means thereby provi...