Reproductive Phenology of the Brown Alga Analipus japonicus in Peter the Great Bay (Sea of Japan)

The alga Analipus japonicus (Harv.) Wynne displays a distinct seasonal pattern in its development in Peter the Great Bay (Sea of Japan). In winter and spring, it occurs only in the form of basal crusts, and vertical axes develop in the summer–autumn period. It reproduces mostly asexually from July to November. Algae with unilocular sporangia occur very seldom, only in June and July.     

Cloning of aroG, the gene coding for phospho-2-keto-3-deoxy-heptonate aldolase(phe), in Escherichia coli K-12, and subcloning of the aroG promoter and operator in a promoter-detecting plasmid

Defective transducing phages carrying aroG, the structural gene for phenylalanine (phe)-inhibitable phospho-2-keto-heptonate aldolase (EC 4.1.2.15; previously known as 3-deoxy-D-arabinoheptulosonate-7-phosphate synthetase[phe]), have been isolated, and DNA from two of these phages has been used to construct a restriction map of the region from att lambda to aroG. A 7.6-kb PstI-HindIII fragment from one of these phages was cloned into pBR322 and shown to contain aroG. The location of aroG within the 7.6 kb was established by subcloning and Tn3 transpositional mutagenesis. A fragment carrying the aroG promoter and operator has been cloned into a high copy number promoter-cloning vector (pMC489), and the resulting aroGpo-LacZ' (alpha) fusion subcloned in a low copy number vector. Strains with this fusion on the low copy number vector exhibit negative regulation of beta-galactosidase expression by both phenylalanine and tryptophan and positive regulation by tyrosine in a tyrR+ background.     

Morphometry and composition of aragonite and vaterite otoliths of deformed laboratory reared juvenile herring from two populations

Vaterite otoliths were sampled from two reared populations (Celtic and Clyde Seas) of juvenile herring Clupea harengus. The crystallography, elemental composition and morphometry were analysed and compared with those of normal aragonite otoliths. The incidence of vaterite otoliths in the juveniles sampled (n = 601) ranged from 7·8% in the Clyde population to 13·9% in the Celtic Sea population, and was 5·5% in the small sample (n = 36) of wild adults examined. In all but one case fish had only one vaterite otolith; the corresponding otolith of the pair was completely aragonite. Although the majority of the juveniles sampled showed craniofacial deformities, there was no link between the skull or jaw malformation and the incidence of vaterite otoliths. All vaterite otoliths had an aragonite inner area, and vaterite deposition began sometime after the age of 90 days. The vaterite otoliths were larger and lighter than their corresponding aragonite partners, and were less dense as a consequence of the vaterite crystal structure. The vaterite areas of the otoliths were depleted in Sr, Na and K. Concentrations of Mn were higher in the vaterite areas. The transition between the aragonite inner areas and the vaterite areas was sharply delineated. Within a small spatial scale (20 μm³) in the vaterite areas, however, there was co‐precipitation of both vaterite and aragonite. The composition of the aragonite cores in the vaterite otoliths was the same as in the cores of the normal aragonite otoliths indicating that the composition of the aragonite cores did not seed the shift to vaterite. Vaterite is less dense than aragonite, yet the concentrations of Ca analysed with wavelength‐dispersive spectrometry (WDS) were the same between the two polymorphs, indicating that Ca concentrations measured with WDS are not a good indicator of hypermineralized zones with high mineral density. The asymmetry in density and size of the otoliths may cause disruptions of hearing and pressure sensitivity for individual fish with one vaterite otolith, however, the presence of vaterite otoliths did not seem to affect the growth of these laboratory reared juvenile herring.     

Automated Food-Procuring Movement-Related Neuronal Activity in the Basolateral Amygdala of the Rat

We studied the impulse activity of neurons of the basal and lateral amygdalar nuclei generated when experimental animals (rats) performed fast stereotyped food-procuring movements by the forelimb. Within the basolateral amygdala, there are neurons whose activity is related to different stages of getting off the food, and according to the characteristics of their spiking these neurons should be divided into a number of subpopulations. Activation forestalling the movement initiation by 0.5-1.0 sec was observed in most neurons of the basolateral amygdala; this is considered a manifestation of excitation related to a motivation component of the food-procuring behavior. Activation of amygdalar neurons following movement initiation can result from generation in this structure of additional excitation necessary for successful performance of a complete food-procuring motor cycle.     

Nearest Neighbor Classification Rule for Mixtures of Discrete and Continuous Random Variables

In this paper very simple nonparametric classification rule for mixtures of discrete and continuous random variables is described. It is based on the method of nearest neighbor proposed by Cover and Hart (1967). The bounds on the limit of the nearest neighbor rule risks are given. Both lower and upper bound depend on the Bayes risk and the loss function. Finally the method is compared with other existing methods on some practical data set.     

Application of polyethyleneimine cellulose for the class separation of steroidal carboxylic acids from neutral steroids and pigments in urine

Metabolites of corticosteroids that contain the 21-oic acid moiety are found in human urine. The acids from neutral steroids and urinary pigments have been separated by passing the mixture through a column of polyethyleneimine cellulose. The acids adhering to the column are quantitatively eluted with dilute formic acid. The purified preparation is suitable for derivatization and chromatographic analysis.     

Internode length in Pisum. I. The effect of the Le/le gene difference on endogenous gibberellin-like substances

The allelopathic potential of the dry fruits of Washingtonia filifera (L. Linden) H. Wendl. was investigated. Leachates from fruits inhibited the germination of lettuce, wheat, red cabbage and cucumber seeds. The inhibitory effect was partly neutralized by kinetin (20 mg 1⁻¹) and gibberellic acid (50 mg 1⁻¹). The effect of kinetin was more pronounced at 25°C than at 20°C. Substances inhibiting germination were localized in the pericarp of the fruit and were resistant to high temperature.     

The distribution of carbohydrate side chains along the polypeptide chain of glucoamylase

Glucoamylase is a starch-hydrolyzing enzyme with a glycoprotein structure, used industrially for the conversion of starch to glucose, citric acid, corn syrups, and high-fructose sweeteners. This enzyme possesses an unusual type of structure in which many carbohydrate side chains are linked O-glycosidically to serine and threonine residues of the polypeptide chain. The carbohydrate side chains may be single monosaccharide residues or oligosaccharides of mannose, glucose, galactose, and in some cases N-acetylglucosamine. New data from experiments on the CNBr fragmentation of glucoamylase followed by chemical and immunological characterization of the fragments show that the carbohydrate side chains are distributed randomly along the polypeptide chain. Such a structure is appropriately termed a random model reprensentation for the glucoamylase molecule.     

Habitat selection in rock pool corixids: the effect of local density on dispersal

The corixid species breeding in temporary rock pools of Baltic archipelago live in a highly fragmented and unpredictable habitat. Shallow rock pools can dry out and be refilled repeatedly during a summer causing high mortality of immatures. In deeper pools, young nymphs face intense competition by older stages including cannibalism. The adult corixids move frequently between rock pools and are thus able to use currently available habitat for reproduction. In this dispersal behaviour, the ability to assess the local population density and hence select the more suitable low density patches would be advantageous. We studied the effect of local population density on the frequency of dispersive flights of Arctocorisa carinata (Sahlberg) and Callicorixa producta (Reuter) experimentally, using rock pools from which nymphs of both species were removed. The dispersal rates of marked C. producta adults were significantly lower from experimental rock pools than from normal density controls, leading to a concentration of C. producta adults in the experimental rock pools. Indications of immigration rate differences between the experimental and control pools were also observed. No clear differences were found in the superior competitor A. carinata.