Model of discharge patterns of units in the cochlear nucleus in response to steady state and time-varying sounds

A model for the coding of sounds in the discharge pattern of single neurons in the auditory periphery is described. The model consists of a non-linear differential equation and a conventional diffusion neuron model. The same model describes 1) the unit interspike interval distribution in response to continuous stimulation, 2) the response to tone bursts, as well as 3) the responses to sinusoidally amplitude-modulated stimuli. The parameters of the model are determined quantitatively for each neuron. The responses of a certain unit can be described by 5 parameters.     

Effect of cyngal on gastric secretion in rats]

The authors studied the influence of gallic salt of cynoglossophin-heliosupin alkaloid (cyngal), extracted from Cynoglossum officinale L. on the gastric secretion of rats. Cyngal proved to stimulate the secretory function of the rat stomach, beginning from the dose of 0.25 mg/kg. This action is explained by the capacity of the preparation to release histamine from the labile depot.     

Silage studies IX biochemical changes in microbe-free silage

Summary If the aseptic plant material is regarded as a substrate for preservative microbial activity, it may be said that both the nitrogen and carbohydrate components undergo changes due to the influence of native enzymes in the plant material. These changes may very well be reflected in the microbial activity in a silage.It is interesting to compare the findings of this investigation, which show that during the days immediately after ensilage practically no changes take place when no bacteria are present. In a non-sterile ensilage, on the other hand, it is during this early stage that the briskest bacterial activity takes place.The chances of, say, an acid-forming microbial process actually lowering the pH in order that preservation of the material may take place are directly counteracted by the action of native enzymes of the vegetable material. During the days immediately after ensilage, however, if other conditions are favourable, microbial activity may clearly determine the whole course of events, and may possibly even inactivate the processes of the plant material itself.As is evident from the experiments described above, the activities inherent in the ensiled material itself are of no mean proportions. Further study of the mutual relationship of the ensilage and the various microbial fractions is therefore particularly necessary in order to be able to understand a number of processes of fundamental importance in biological preservation of plant material.     

Aseptic cultivation of higher plants

Summary A short survey of different problems connected with the aseptic cultivation of higher plants is given.Accounts have been given of experiments in which antibiotics and fungicides have been used, as well separately as in combination, as surface-sterilizing agents.The use of chlorine as a sterilizing agent for the surface-sterilization of pea seed has been investigated and an account given of the importance of damage to the skin of the seed in the procedure.Procedures for the surface sterilization of oats and barley, and for pea seed, have been developed.Various arrangements in which the aseptic cultivation of higher plants may be carried out are described.     

The formation of L-3-phosphoglyceric acid by ribulose-1,5-bisphosphate carboxylase

A sensitive and reliable method to determine the stereochemical composition of 3-phosphoglyceric acid is presented. Results obtained with this method show that 3-phosphoglyceric acid formed in the ribulose-1,5-bisphosphate carboxylase reaction is a mixture of 10% L-3-PGA and 90% D-3-PGA.     

Nonspecific and antigen-specific adhesiveness of circulating lymphocytes in dysentery patients undergoing combined therapy using thymalin and indomethacin

Nonspecific adhesiveness of lymphocytes to polyacrylonitrile fiber and the antigen-specific adhesiveness of T-lymphocytes to Shigella flexneri pellicular immunosorbent have been studied in dysentery patients. Short courses of treatment with indomethacin, but not with thymalin (the preparation of thymic hormones), used for immunomodulation, have accelerated the normalization of nonspecific lymphocyte adhesiveness during regression of the disease, while indomethacin, in contrast to thymalin, inhibits antigen-specific T-lymphocyte adhesiveness which increases with the development of immune response.     

Genetic evidence that the putative receptor binding domain of apolipoprotein B (residues 3130 to 3630) is not the only region of the protein involved in interaction with the low density lipoprotein receptor

We have searched for sequence differences in the region of the apolipoprotein B (apo B) gene encoding amino acids 3130-3630 in eight individuals with reduced affinity of low density lipoprotein (LDL) for the normal LDL-receptor. All individuals were hypercholesterolaemic and were selected either on the basis of reduced fractional catabolic rate (FCR) of autologous LDL or substantially reduced binding of their LDL to normal LDL-receptors determined by an in vitro cell growth assay using the U937 macrophage-like cell line. Segments of the apo B gene were amplified by the polymerase chain reaction. Using a combination of cloning and sequencing the amplified fragment, together with chemical cleavage mismatch analysis, no sequence differences were identified in this region of the gene. We therefore conclude that variation outside the region of the apo B gene that codes for amino acids 3130-3630 must be responsible for the reduced LDL clearance in these patients.