Smooth septate junctions from the midgut of the cricket, Acheta, and the horseshoe crab, Limulus, as well as Hydra-type septate junctions from the epidermis of Hydra have been studied by freeze-fracture after direct freezing using the liquid helium-cooled copper block/slam freezing method. The exoplasmic fracture face at both types of septate junction exhibits rows of closely packed but irregul...

The structure of the epithelial cells of the alimentary tract of Fasciola hepatica was investigated by means of light and electron microscopy. Tissue prepared for electron microscopy was fixed in 1 per cent osmium tetroxide, buffered with veronal to a pH of 7.4, and embedded in butyl methacrylate with 1 per cent benzoyl peroxide as a catalyst. Polymerisation was carried out at 60 degrees C. The...

We report experimental laboratory studies on developing conductive pathways, or wires, using protoplasmic tubes of plasmodium of acellular slime mould Physarum polycephalum. Given two pins to be connected by a wire, we place a piece of slime mould on one pin and an attractant on another pin. Physarum propagates towards the attract and thus connects the pins with a protoplasmic tube. A protoplas...

For purposes of description, the cells of the Malpighian tubules of the grasshopper may be divided into basal, intermediate, and apical zones. The basal zone of the cell contains what appears to be an elaborate infolding of the cell membrane at the base. This condition results in the basal cell cytoplasm being divided into many compartments. The compartments contain mitochondria that are often ...

in this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. liquid atomization was achieved by using an ultrasonic nozzle. the nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 khz. the induction method was used for charging the output droplets. all experiments w...

A method was devised for estimtaing the electrical resistance between the cytoplasm of adjacent cells of the red marine alga Griffithsia globulifera. A very high resistance was found, which argues strongly against the existence of protoplasmic continuity in this species.

LOEB (9), KUNTZ et al. (6), SCATCHARD et al. (11), and others have made use of osmotic pressure measurements to calculate the molecular weights of pure proteins such as gelatin, crystallized enzymes, and crystallized serum albumen. Protoplasmic proteins have not been investigated. Yet it would be of some interest to know the average molecular weight of a plant's protoplasmic proteins. Such info...

Mathematical models for microbial growth in batch and continuous cultures are formulated. The models have been referred to as distributed models since the microbial population in a culture is looked upon as protoplasmic mass distributed nniformly throughout the culture. Growth is regarded as the increase in this mass by conversion of medium components into biological mass and metabolic products...

the effect of ph, different concentration of tween 80 and calcium ion on the stability of limonene-in-water emulsions stabilized by various concentration of sodium caseinate (2, 5 and 10%) was evaluated. to this end, emulsions were prepared by ultrasound and their quality attributes including size distribution, mean diameter of droplets, specific surface area and span number were studied as a r...

and give rise to, cells which are more or less removed from their normal places. Thus polar bodies and ectoderm cells may be caused to form at the vegetative pole or at any other point on the surface of the egg instead of at the animal pole; nevertheless the protoplasmic portions of the yolk-containing cells return to the animal pole when centrifuging ceases unless otherwise prevented. In some ...