Spatfall and growth of the mussel,Mytilus edulis edulis,in hanging culture in the Westfjord area (68°5′ N), Norway

The growth of a population of Mytilus edulis edulis collected as spat at Hamarøy, Westfjord was followed for three growth seasons. The growth rate was similar to that at Trondheim (580 km south) but markedly dissimilar from that at Tromsø (200 km north). This suggests that there is a long coastal region of equal or similar growth for mussels, running from Trondheim about 600 km northwards to Westfjord.     

Effect of polysaccharides on the gelatinization properties of cornstarch dispersions

Konjac glucomannan (KG, neutral), carboxymethylcellulose (CMC, negatively charged), and chitosan (positively charged) were added to cornstarch dispersions to study the effect of polysaccharide-starch interactions on starch gelatinization properties. Pasting and retrogradation properties were measured with a rheometer and DSC. Swelling properties of the starch granules were determined by solubility index, swelling power, and particle size distribution. Depending on the nature of the different polysaccharides, viscosities of cornstarch dispersions were affected differently. The particle size distributions were not influenced by the addition of any of the polysaccharides. Swelling results showed that the KG and CMC molecules interacted with the released or partly released amylose in the cornstarch dispersions. This was correlated with the short-term retrogradation of the starch pastes being retarded by the additions of KG and CMC. However, the chitosan molecules appeared not to associate with the amylose, so the retrogradation of the chitosan-cornstarch dispersions was not retarded.     

An apparatus for long term biological experiments in running water at temperatures close to freezing

An open aquarium system in which water temperatures can be manipulated and controlled close to freezing point has been constructed. Technical details and the results of a working trial lasting six weeks are reported.

The equipment was constructed in order to be able to simulate river water temperatures, and changes in these due to hydroelectrical development in Arctic regions. The incubation of Atlantic salmon eggs was of particular interest. Other applications include growth studies and nutritional physiology of aquatic organisms at low temperatures. The system can be used with both freshwater and seawater.     

Field trials with trimethoprim and sulphadoxine

Extract

Sir, — Trimethoprim (2,4-diamino-5-(3,4,5,trimethoxy-benzyl) pyrimidine) is an inhibitor of the enzyme dihydrofolate reductase and blocks its action in bacterial cell metabolism. Sulphonamides act similarly on a different enzyme and, when the two are used in combination, clinical results are much enhanced and a synergistic effect has been shown in vitro.     

The veterinary profession in New Zealand

Extract

At the beginning of this new decade, the veterinary profession in New Zealand faces a future of boundless opportunity. After a rapid and difficult growth period of twenty years, the profession is now well established as an entity, and if we, its members, show wisdom and vision, we can ensure that veterinary science will take its rightful place in the progress of New Zealand. If we fail, the profession will find itself playing a minor role in the future. We dare not allow ourselves to just drift into the years ahead.     

Immunization of lambs against pulpy kidney and tetanus

Extract

Over a period of years it has become standard practice in certain areas of New Zealand to take precautions against tetanus following lamb marking. These areas are fairly well defined and the main regions are those of Hawke's Bay and the southern half of the South Island. In these areas, losses following lamb marking, many being due to tetanus, can be high if no preventive measures are taken. It has frequently been observed that conditions favouring the development of Clostridium tetani accompany certain operations at marking, and that this risk has increased because of the use of rubber rings and searing irons at marking. This was to be expected since anaerobic conditions in deep-seated wounds will favour the growth of Cl. tetani.     

A trial of polyvalent staphylococcus vaccine for mastitis prevention

Extract

In the 1961–62 season, a small vaccination trial against staphylococcal mastitis was conducted in the district served by the Albertland Co-operative Dairy Company Ltd, and the results are herein reported.