ALBERT

Description: The dissolution rates of spheres of two magnesian olivines, two plagioclases, and quartz in tholeiitic basalt have been determined at three super-liquidus temperatures and one-atmosphere pressure. There are considerable differences in the rates among the minerals, e.g. at 1210°, 12° above the liquidus temperature of the basalt, labradorite dissolves at 86 µm/h. and the magnesian olivines at 9 and 14 µm/h. The rates are not time dependent and this, coupled with the existence of concentration gradients in the composition of quenched melt adjacent to partially dissolved crystals, indicates that the dissolution rates are dictated by a combination of diffusion and convection of components to and from the crystal-liquid interface. Values for the activation enthalpy of dissolution are small for quartz and plagioclase (40–50 kcal mol−1) but large for olivine 73–118 kcal mol−1). Dissolution of plagioclase in rock melts seems to be a much more rapid process than crystal growth, whereas olivines apparently dissolve and grow at similar rates. Crystal dissolution is sufficiently slow that ascending, crystal-bearing magma may become superheated and yet fail to dissolve the crystal fraction before quenching; this may be the reason that olivine phenocrysts are often rounded.

Description: Distributions of the species of Foraminifera (living and dead) forming the greater part of the foraminiferal faunas in marshes in Poponesset Bay, Massa- chusetts, have been studied. Eight stations were sampled bimonthly for one year (August, 1956 to September, 1957). The marsh environments vary from almost non-marine (with tidal influence) to near marine. Arenoparrella mexicana, Haplo- phragmoides hancocki, Tiphotrocha comprimata, and Trochammina macrescens de- crease with increasingly marine conditions, whereas Jadammina polystoma and Trochammina inflata increase. Other species such as Ammobaculites dilatatus, Am- motium salsum, Miliammina fusca, and Protelphidium tisburyense fluctuate inde- pendently of the degree of brackish or marine conditions. Unknown factors govern- ing micro- and macroenvironments probably play an important part in controlling distributions. Suggested factors are type of vegetation, chemical factors, pH, nutrients and food. Calcareous specimens are rapidly destroyed after death pre- sumably due either to the ability of the living form to resist acidity or to a postu- lated increase in acidity immediately below the sediment surface, more probably the latter. This destruction of the tests is of importance in the interpretation of ancient marsh environments. Many species, including the calcareous ones, had their largest living populations in June or September and their smallest in December or February. There were some exceptions such as Miliammina fusca which showed an increase in winter. The total living populations were greatest in June and lowest in December, which may be related to maximum temperature and time of greatest reduction in temperature respectively. Multiple sampling showed that distribu- tions at any one station were fairly uniform although nearby samples in different microenvironments in some cases vary considerably.

Description: The kinetics of methane hydrate decomposition was studied using a semibatch stirred-tank reactor. The decomposition was accomplished by reducing the pressure on a hydrate slurry in water to a value below the three-phase equilibrium pressure at the reactor temperature. The data were obtained at temperatures from 274 to 283 K and pressures from 0.17 to 6.97 MPa. The stirring rates were high enough to eliminate mass-transfer effects. Analysis of the data indicated that the decomposition rate was proportional to the particle surface area and to the difference in the fugacity of methane at the equilibrium pressure and the decomposition pressure. The proportionality constant showed an Arrhenius temperature dependence. An estimate of the hydrate particle diameters in the experiments permitted the development of an intrinsic model for the kinetics of hydrate decomposition.

Description: 1. Effects of noradrenaline and the related compounds adrenaline, dopamine, octopamine, tryamine, clonidine and isoprenaline were studied in isolated heart preparations from the cuttlefish Sepia officinalis L. 2. All analogues produced a positive inotropic affect, with noradrenaline being the most potent substance. The chronotropic effects of the tested compounds differed widely. 3. The action of substances of the phenylethanolamine group were not antagonized by propanolol but were partly antagonized by phentolamine. 4. Serotonin and its analogues also produced cardio-excitation. These effects were blocked by cyproheptadine but not by methysergide. 5. These results indicate the presence of two different receptors in the Sepia myocardium: one type reacting with noradrenaline most effectively and a second type being stimulated by serotonin.

Description: This chapter discusses the Maillard reaction. Results of the many investigations into the mechanism of the Maillard reaction support one of two main theories. The first assumes the formation of glycosylamines that undergo the Amadori (or, for ketoses, the Heyns) rearrangement. The 1-amino-l-deoxyketose derivative (or 2-amino-2-de- oxyaldose derivative) formed may be dehydrated and cyclized to form furan derivatives, or it may enolize. In either case, intermediates that are readily transformed into brown compounds are formed. A third possibility is for the deoxy sugar derivative to react with more amino acid to form colored products. The many workers who have supported this mechanism found also that optimum conditions for occurrence of the Maillard reaction are (1) fairly low water content, (2) a pH of 7 to 10, and (3) a high temperature. Nevertheless, some reaction occurs under conditions far removed from these, but in the absence of moisture there is no reaction. The formation of an acyclic Schiff base as an initial step is not very likely, since replacement of the aldose by salicylaldehyde caused only a very small loss of amino groups. The second theory of the mechanism of the browning reaction is of recent origin and maintains that the browning reaction and the Maillard reaction are separate and distinct. Browning, according to this school of thought, is due to the effect of pH on the sugar and can occur over a wide range of pH, whereas the Maillard reaction proceeds only in alkaline media.

Description: The octopus Eledone cirrhosa (Lamarck 1798), enclosed in a small chamber of flowing sea water, was tested for responses to water-borne chemicals. Incidence of body movements and change in ventilation rate were recorded by a non-invasive technique- At concentrations no more than 1x10 -4M at the animal, the octopuses responded to betaine, proline, alanine, lactic acid, and serine (order of decreasing sensitivity)- Glutamic acid and trimethylamine oxide were considerably less stimulatory, arginine and taurine were hardly more effective than sea-water controls.

Description: Fourteen instances of whales entangled in submarine cables are reported. Ten entanglements occured off the Pacific coast of Central and South America. Six cases occured in about 500 fathoms, with 620 fathoms the maximum depth reported. Five entanglements occured in the period, Februray-March-April. All whales positively identified were sperm whales. The submarine cable was generally wrapped around jaw and often around the flukes and fins. The cable was rarely broken but always badly mauled. The entanglements often occured near former repairs where there is a chance for extra slack cable on the bottom. Two photographs of a sperm whale entangled in a cable and one photograph of a whale-jaw entangled in a cable are presented. It is concluded that sperm whales often swim alog the sea floor in depths as grat as 620 fathoms. It is suggested that the whales become entangled while swimming along with their jaw plowing through the sediment in search of food. It is possible that the whales attack tangled masses of slack cable mistaking them for items of food.

Description: Surveys of the interdial macrofauna and sediment characters of Nigg Bay, Moray Firth, were carried out between 1981 and 1985. Permanent stations were located at the intersections of a half-kilometre grid covering the entire interdial area and sampled for infauna using replicate cores. Estimates were also made of mussel and lugworm densities from quadrats and cast counts respectively. The biomass of selected species that constitute important resources for higher tropic levels were also estimated. The sediment for each station was analysed for median particle diameter and slit content. The infaunal data were analysed by Detrended Correspondence Analysis. This indicated that tida height was the most important factor governing the distribution and abundance of the interdial communities. Sediment characters were only poorly related to distribution patterns. The bay has a rich fauna and is biologically similar to other outer bays of the Moray Firth, which, like Nigg, are important areas for wildfowl and waders. Comparison of survey data from different years indicate that there are natural cycles in some sediment and biological characters of Nigg Bay.

Description: Cephalopod beaks recovered from stomach samples taken from l 4 sea bird species in the southern Benguela region off Southern Africa and from one species at Sub-Antarctic Marion Island, were identified as far as possible, counted and the lower rostral lengths (LRLs) measured. Dorsal mantle lengths (DMLs) and body masses of the cephalopods eaten were estimated. The results of analyses by percentage frequency of occurrence and numerical abundance are discussed with reference to present knowledge of the distribution of cephalopods eaten by sea birds in the areas studied. Division of the cephalopod component of seabird diets into species which float, and species which sink, after death indicates that the birds forage on dead or moribund cephalopods on the surface, rather than catching live bioluminescent cephalopods at night.