ALBERT

Description: The coagulation of hydrosols was investigated theoretically and experimentally. A reduced form of the particle size distribution function, designated “self-preserving,” was found to satisfy Smoluchowski's equations of coagulation by Brownian motion and shear flow. Brownian motion coagulation experiments with two heterogeneous hydrosols showed that the distributions were self-preserving. The rate of coagulation for heterogeneous systems was found to be second order in total particle concentration, consistent with the self-preserving form of the distribution function. Coagulation experiments were carried out in a simple laminar shear field using a homogeneous Dow polystyrene latex dispersion. Smoluchowski's shear flow theory was confirmed for shear rates ranging from 1 to 80 sec.−1 The shear coagulation of a heterogeneous emulsion was studied at several shear rates, and the size distributions were self-preserving.

Description: Fecal excretion of calcium of endogenous origin has been measured in 52 studies in 33 adult human subjects, under full metabolic balance conditions. Endogenous fecal calcium averaged .130 ± .047 Gm. per day, was positively correlated with both fecal calcium and dietary calcium and was inversely correlated with fractional calcium absorption. The regression line relating endogenous fecal calcium with fractional absorption allowed estimates for total intestinal calcium secretion at both zero and 100 per cent absorption; from these estimates it was calculated that approximately 15 per cent of the total intestinal calcium secretion was nonabsorbable even under conditions when dietary calcium was completely absorbed (presumably because it enters the gut caudad of the absorption sites). Total intestinal calcium secretion, calculated so as to allow for this nonabsorbable fraction, averaged .194 ± .073 Gm. per day, and could not be correlated with age, sex, dietary calcium intake, caloric intake, urine calcium, or plasma calcium. A weak correlation with body size (weight, surface area) was observed. The conditions studied were principally disorders of bone, calcium, and parathyroid metabolism, and in most of them total intestinal calcium secretion appeared identical. The sole exception was seen in two studies on a patient with acromegaly, in which total intestinal calcium secretion was over twice the mean value for the remainder of the group.

Description: Analyses of bottom trawl samples and feeding experiments in the laboratory revealed a reproduction period ranging from late March to early August in Eledone cirrosa of the Catalonian Sea (Western Mediterranean). The embryonic development, studied for the first time on eggs laid in the laboratory, shows no basic difference from that of other Octopodiae. The newly hatched animals are planctonic; Morphologically, this feature is expressed by a relatively small arm-length.

Description: Five species of Sepiola were reared in the laboratory from egg to adult size. Spawning was achieved in 3 species of Sepiola afteer 5 to 7 months. The growth rate of the species reared did not depend upon temperature, which ranged from 12,5° to 20°C. A fairly constant size increase (2,5mm mantle length/month) was observed in Sepiola during the 5 months after hatching. In Sepietta, the same growth rate was observed until the fourth month after hatching, when it increased to the rate of 5 mm mantle length/month.

Description: A technique for rearing the loliginid squids Sepioteuthis sepioidea and Doryteuthis plei is reported. Specimens of the former were reared from eggs to sexually mature adults, and maintained for a maximum of 146 days; adult D. plei were maintained for 38 days. Choice and quantity of food was most important for the survival of all sizes, particularly young squid. Newly hatched specimens thrived on Mysidium columbiae. Both species fed at a rate of 30 to 60% of their body weight daily; starvation occurred when intake fell below 10 to 15%. Food conversion efficiency averaged between 10 to 20%. Growth was rapid and steady. S. sepioidea grew to a maximum of 105 mm and 77 g in less than 5 months; D. plei grew an estimated 20 mm/month. Experimental data indicate a lethal minimum salinity for both species at about 27‰. Lethal minimum and maximum temperatures for young S. sepioidea are 17.5° to 18.0°C, and 32.5° to 33.0°C, respectively. Young consume 0.64μl O2/mg wet weight/h. Opaque tanks, with a semi-natural bottom substrate and special ultra-violet (UV) illumination, are advantageous for rearing and maintenance.

Description: This chapter throws the attention on the methods of sampling the benthos, which has been directed mainly to the operation of the gear at sea and to such other factors as may influence sampling methods. This chapter briefly traces the history of benthos investigations, and then considers how far the instruments now available provide with the quantitative samples. It also shows how advances in other fields, such as radio-position finding, sonar and electronic equipment have increased the precision of our sampling methods. Moreover, sorting and sieving on board ship can be considered and brief mention made of methods of soil analysis and biomass determination. This chapter discusses the two possible approaches for the development of satisfactory quantitative collecting methods. First the improvement of the grab-type of instrument, with particular reference to increasing penetration and the perfection of release gear for the open sea, and second; the development of a wide-core sampler, like the Knudsen sampler, which works satisfactorily in the open sea. Moreover, statistics need to be even more fully applied, where collecting methods justify them, to such problems as the degree and scale of dispersion of individuals.

Description: Shipworms or Teredinidae may be dispersed either as adults in floating wooden objects or as pelagic larvae drifting near the sea surface. Five shipworm species, i.e., half of those having an amphi-Atlantic geographical distribution, are known also to have pelagic phytoplanktotrophic larvae which can be carried by ocean currents. From a series of 742 plankton samples taken from throughout the temperate and tropical North Atlantic Ocean, it can be shown that shipworm larvae are not uncommon in the open sea. Teredinid veligers were found in 19% of all samples taken. One species of larvae, identical in all details to that described by Rancurel (1965), is particularly prevalent and is tentatively identified as Teredora malleolus (Turton). A definitive identification will be possible only after the pelagic larvae of the other Atlantic species are known. The larvae of Teredora malleolus are found throughout the North Atlantic Gyre and the adjacent temperate and tropical seas, and from scattered records in the South Equatorial Current. Larvae of other unidentified Teredinidae species were also found. The distance that larvae may be transported depends upon the length of pelagic larval development and the velocity of the currents. From the known current velocities it can be shown that, even in a few weeks, larvae may be dispersed many hundreds of kilometers. The geographical distribution of shipworm larvae suggests that they are carried along the coasts of continents and even across ocean basins, and that this dispersal must be an important factor in the geographical distribution of the adult forms and in the maintenance of genetic continuity between populations otherwise isolated from one another.

Description: Reviews the major deep-sea expeditions from that of HMS Challenger in 1873 to 1960. Emphasis is on the increasing sophistication of vessels and equipment used, the growth of international cooperation and the proliferation of branches of oceanographic studies. Arctic work by Nansen, Sverdrup, recent Soviet scientists, the Scripps Institution and the Norpac program are mentioned (maps). Vessels used during the period and their activities are tabulated. Two maps show cruises of the Atlantic Polar Front Program Jan-Dec 1958 in the Greenland and Barents Seas

Description: A study is described which attempts to obtain information about the vertical correlation of ocean currents at frequencies higher than inertial. Current velocity and temperature data for sensor separations of 4–12 m were taken with a mooring at ‘Site D’. The coherence and phase spectra for velocity component pairs reveals that motions are rotational at low frequencies. A cut-off frequency exists above which coherence drops to low values. The limiting frequency coincides with the minimum Väisälä frequency of the total water column. These cross-spectral properties support the assumption that the motion in this frequency range is governed by internal wave dynamics. The coherence and phase spectra of temperature pairs indicate that a field of temperature structure is superimposed on the mean field which is weakly correlated to the field of motion.