Primary production in a tropical fish pond at Aligarh,India

Summary Seasonal fluctuations in gross and net primary production values were quite apparent in surface waters and showed a bimodal type of distribution. The values were generally high during post winter months (March to May) and low during winter (February) and monsoon months (July and August). At different depths the rate of primary production was always found decreasing from surface to bottom. The rate of photosynthesis was found to be highly variable from time to time and at different depths.Respiratory rate was found to be increasing from surface to bottom perhaps due to decomposition of organic matter and high bacterial growth at the increasing depths. A close relationship was found between the transparency and primary production values. Phosphate-phosphorus was found to be directly related with the gross primary production values. However, there was no relationship between nitrate-nitrogen and production values. An inverse relationship was shown between ammonia-nitrogen and the production values. Fluctuations in chlorophyll were also found significantly related with the gross primary production.     

Fungal plasmocoagulase

Summary The cell extracts isolated from 73 species of fungi belonging to different taxonomic groups were studied to ascertain the presence of plasmocoagulase and protease. Plasmocoagulase was found to be widespread among these microorganisms. They were most constantly found in yeasts and yeastlike fungi. The active substance was not found in culture media. When studying the purified preparation ofCandida albicans plasmocoagulase in comparison with staphylocoagulase the mode of action of both coagulases was found to represent the enzymatical proteolysis of prothrombin with the formation of thrombin or thrombinlike substance.     

Karyotypes of eight species of phytoseiid mites (Acarina: Mesostigmata) from Madagascar

Haplo-diploidy was found to be regular with eight species of phytoseiid mites occurring in Madagascar. The chromosome number in all species was n=4. A variation was found with respect to centromere position.     

Optimization of culture conditions and characterization of a new lectin from <Emphasis Type="Italic">Aspergillus niger</Emphasis>

Lectin activity was determined on solidified medium containing agar and in broth cultures of Aspergillus niger. The fungus was found to express 16 times higher activity in broth cultures, when grown in a medium adjusted to pH 5.5 at 30°C under stationary condition. Lectin activity was found to be expressed by 6-day-old mycelial cultures with maximum activity being expressed on 9th day of incubation. The crude lectin (total titer 1280) was found to be precipitated at 50% saturation of ammonium sulphate with 2.4-fold purifi cation and 83% yield in the precipitate. The partially purifi ed lectin was found to agglutinate all human, rat, mice and pig erythrocytes. It was found to have a strong binding affinity to mucin, asialofetuin and inulin.     

Further studies on lactate dehydrogenase from serum of leukemic individuals

The kinetic properties of SLDH were investigated in untreated patients with acute leukemia at 37 degrees. SLDH was found to be inhibited by high pyruvate concentrations to a degree which depended on the pH of the reaction mixture; the degree of inhibition of normal SLDH at pH 7.5 was much higher than leukemic SLDH. 0.4M citrate was found to activate SLDH reaction rate at low pyruvate concentrations, while it was inhibitory at high pyruvate concentrations; the degree of inhibition being greater for leukemic SLDH than for normal SLDH. Citrate was also found to be a non-competitive inhibitor with respect to NADH and the value of Ki was determined. Methanol (3-4M), acted as a strong inhibitor to SLDH. The inhibition was found to be purely non-competitive with respect to pyruvate. Ki was calculated to be four times higher for leukemic SLDH than for normal SLDH.     

Enumeration of Listeria monocytogenes in raw milk

Enumeration of Listeria monocytogenes in raw milk was compared by direct plating and Most Probable Number (MPN) techniques involving both direct and two-stage enrichments. Direct plating was found to lack sensitivity for the enumeration of low numbers of listerias found in milk but an MPN technique with direct selective enrichment was found to be more suitable than one with two-stage enrichment.     

Chemical modification of rubber wood with styrene in combination with a crosslinker: effect on dimensional stability and strength property

Chemical modification of rubber wood (Hevea Brasiliensis) was carried out by impregnating the wood with styrene and in combination with a crosslinker Glycidyl Methacrylate (GMA). Polymerization was carried out by catalyst heat treatment. The dimensional stability in terms of % volumetric swelling and anti-shrink efficiency was determined and found to be improved on treatment. Water absorption was also found to be decreased considerably for treated wood samples. Mechanical strength of the treated samples in terms of modulus of rupture and modulus of elasticity were also found to be improved. The wood polymer interaction was confirmed by FT-IR spectroscopy. Biodegradability of the wood/polymer composites was determined and found to be improved on treatment with styrene/styrene-GMA.     

Isolation and characterization of a bacteriocin produced by Cicer-Rhizobium

A constitutively expressed bacteriocin from Cicer-Rhizobium was purified to homogeneity. The purified preparation yielded a homogenous protein with a molecular weight of about 29 kDa. This protein was heat stable, unaffected by nucleases and was found to have an iso-electric point (pI) of 4.6. The N-terminal sequence of the protein was found to be M-N-N-N-Y-R-E-L-L-P-I-I-G-P-P-W-A-E-I-E, sharing 78% homology with linocin M18. Bacteriocin bioactivity was correlated with the presence of a 29 kDa protein in the growth diffusates of the culture. A mutant strain unable to produce this bacteriocin was found to have a statistically significant reduction in nodule occupancy and competitiveness against the wild type and indigeneous populations under unsterile conditions. Bacteriocin production by the mutant carrying the complement clone pJNP365 was found to be stable even in an unsterile environment.     

Oxidation of lactaldehyde by cytosolic aldehyde dehydrogenase and inhibition of cytosolic and mitochondrial aldehyde dehydrogenase by metabolites

An enzyme fraction which oxidizes lactaldehyde to lactic acid has been purified from goat liver. This enzyme was found to be identical with the cytosolic aldehyde dehydrogenase. Lactaldehyde was found to be primarily oxidized by this enzyme. Almost 90% of the total lactaldehyde-oxidizing activity is located in the cytosol. Methylglyoxal and glyceraldehyde 3-phosphate were found to be strong competitive inhibitors of this enzyme. Aldehyde dehydrogenase from goat liver mitochondria has also been partially purified and found to be strongly inhibited by these metabolites. The inhibitory effects of these metabolites on both these enzymes are highly pH dependent. The inhibitory effects of both the metabolites have been found to be stronger for the cytosolic enzyme at pH values higher than the physiological pH. For the mitochondrial enzyme, the inhibition with methylglyoxal was more pronounced at higher pH values, whereas stronger inhibition was observed with glyceraldehyde 3-phosphate at physiological pH.     

A protein associated with prodigiosin formation in Serratia marcescens

A protein associated to prodigiosin formation was found in Serratia marcescens. The protein was not found in nonpigmented strains and was correlated with the pigment level. The protein was about 100 kilodaltons (kDa) and was also found in nonpigmented bacteria of the pigmented strain grown in glucose medium, at high temperature, or under anaerobic condition. The 100 kDa protein was found not in the outer membrane and the periplasm, but in the inner membrane and/or the cytoplasm. The protein was also found singly or dominantly in pigment-protein complexes and pigment-localizing vesicles described in previous reports. These results suggest that the 100 kDa protein is associated with prodigiosin formation.     

Modification of bone formation rate by growth hormone, melanocyte-stimulating hormone, and cortisone in the normal rat

Bone growth and remodelling was studied in rats after injection of growth hormone, melanocyte-stimulating hormone (alpha-MSH), and cortisone daily for 20 days with tetracycline as intravital marker. An increase of both longitudinal and periosteal growth with growth hormone was found. A decrease of both was found after a high cortisone dose. Lower cortisone doses seem to have stimulated periosteal growth. No effect of alpha-MSH was found.     

The association of tree species,landform, soils and erosion on Narrabeen sandstone west of Putty,New South Wales

An exploratory study was made of the tree species, landform, soils and erosional sequence along altitudinal transects from interfluve to stream channel in a valley incised into Narrabeen Group sandstones and shales to the west of Putty, NSW. Four groups of soils with similar edaphic features were identified. These ranged from duplex soils on the apparently old and stable valley rim, through eroded earths on zones of depletion and sandy regoliths with thick surface horizons on zones of accumulation, to mature duplex soils with thick surface horizons on the colluvial toeslopes. Four communities of tree species were found associated with the four groups of soils. A Eucalyptus punctata –E. piperita open-forest was found on the stable valley rim and a related Eucalyptus punctata –E. piperita – E. oblonga open-forest to low woodland was found on zones of depletion. An Angophora costata open-forest was found associated with the sandy regoliths on zones of accumulation and a Eucalyptus viminalis – E. tereticornis open-forest to tall open-forest occurred on thick soils of the colluvial waning slopes. It was found that the landform fitted a hypothetical nine unit land surface model. The soil types and plant communities were found to reflect the dominant contemporary pedogenetic and geomorphic processes which are also used to define the units of this model. Erosion was evident in the catchment, and the sequence of alluvial soils on the valley floor was found to be consistent with previous suggestions of widespread slope instability during the Quaternary period. Speculation is offered about the effects of management of the valley, especially in terms of land surface instability.     

Rapid turnover of the histone-ubiquitin conjugate, protein A24.

The specific activity of protein A24 was found to exceed that of the core histones by 2-3 fold following a brief labeling period. Accordingly, the A24 protein was found to be unstable, with a decay half-life of 90 minutes. When decay of the ubiquitin moiety was measured, it was found to turn over more extensively than the H2A moiety.     

Compositional changes of human mitral valves with aging

To elucidate compositional changes of the mitral valve with aging, the authors investigated the relationships among element contents in the mitral valves. The subjects consisted of 10 men and 15 women, ranging in age from 65 to 102 yr. After the ordinary dissection, mitral valves, lower parts of the interventricular septa, and terminal crests containing the sinoatrial nodes were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The interventricular septa and sinoatrial nodes were used to compare with the mitral valves. With regard to the mitral valve, it was found that extremely significant correlations were found among the contents of Ca, P, Mg, and Na, but no significant correlations were found between the contents of S and elements such as Ca, P, or Mg. Regarding the interventricular septum, it was found that an extremely significant correlation was found between P and S contents; very significant correlations were found between Ca and Mg contents and between Mg and S contents; and a significant correlation was found between P and Mg contents. However, no significant correlation was found between Ca and P contents in the interventricular septa. In the terminal crest containing the sinoatrial node, significant correlations were found among the contents of Ca, P, Mg, and S. The present study revealed that with regard to the relationships among element contents, the compositional change of the mitral valve was intermediate between those of the thoracic aorta and the interventricular septum.     

NADH oxidase from the extreme thermophile Thermus aquaticus YT-1. Purification and characterisation

A protein with NADH oxidase activity from the extreme thermophile Thermus aquaticus YT-1 was purified and characterised. The enzyme was found to have a relative molecular mass of 110,000 and be composed of two subunits of identical size. FAD was found to be present at a concentration of 0.7 mol/mol dimer and was required for activity. During the oxidation of NADH, oxygen uptake takes place with the production of hydrogen peroxide. The enzyme had, with the exception of a higher glutamic acid and tryptophan content, a similar amino acid composition as the NADH oxidase isolated from the mesophile Bacillus megaterium. Purified NADH oxidase was found to have a Km of 39 microM for beta-NADH and a Vmax of 4.68 mumol NADH mg-1 min-1 and was still active at 95 degrees C. Enzymatic activity was found to be independent of pH between 5.0 and 10.5.     

Biochemistry of the cyclic evolution of Triatoma infestans (Vinchuca). IV. De novo biosynthesis of lipids in fat body and testicles

The de novo biosynthesis of lipids by isolated fat bodies and testicles of Triatoma infestans was demonstrated by incubation with 1 14C sodium acetate. The fat body synthetized preferentially triacylglycerols but the label was also found in phospholipids. When hemolymph was added to the medium the label found in diacylglycerols was largely increased. In the testicles the label was preferentially incorporated to the phospholipids and little was found in diacylglycerols and triacylglycerols.     

Latitudinal variation in the body-size of Sparrowhawks Accipiter nisus within Britain

On the basis of Sparrowhawks Accipiter nisus found dead in various parts of Britain during 1979–1991. wing-length was found to provide the most reliable index of overall body-size because it gave the best and most consistent correlations with five other measures of body-size.
A marked latitudinal trend in the body-size of Sparrowhawks was found within Britain, with birds of each sex and age group increasing in size from south to north, in line with Bergmann's Rule. For each successive degree of latitude (approximately 110 km), wing-length increased by an average of 0.86 mm in adult males and O.75 mm in adult females. No obvious west-east trend in body-size was found within Britain.     

Genetic differentiation ofDrosophila melanogaster populations as assessed by two-dimensional electrophoresis

Seven populations ofDrosophila melanogaster, representing a worldwide distribution, were compared using two-dimensional protein gel electrophoresis. A total of 611 protein spots was scored, which probably represent a sample of over 500 loci that were surveyed. Of the protein spots scored, 521 spots were found to be invariant, but another 90 spots were found to be variable among the populations. Of these variable protein spots, 12 were found to be present in only one population. All the populations, except one, had at least one protein spot restricted to itself. However, the Japanese population had by far the most, with five protein spots restricted to this one population, which has been observed in previous studies of private alleles in oriental populations. The mean genetic similarity (F) found among the seven populations was 0.965, with a range of between 0.956 and 0.977. This is similar to previous reports of lower variation found in population genetic surveys using two-dimensional electrophoresis. It was found that the historical relationships among these populations was somewhat congruent with the geographic distribution of the populations, but as in previous studies, it was not exactly coincident.     

Ecology of Vibrio parahaemolyticus in Chesapeake Bay

A study of the ecology of Vibrio parahaemolyticus and related vibrios in the Rhode River area of Chesapeake Bay was carried out over the period December 1970 through August 1971. The incidence of V. parahaemolyticus and related vibrios was found to be correlated with water temperature. The vibrios could not be detected in the water column during the winter months, although they were present in sediment. From late spring to early summer, when water temperatures were 14 +/- 1 C, vibrios over-wintering in sediment were released from the bottom communities and attached to zooplankton, proliferating as the temperature rose. The number of vibrios in and on plankton was reflected in the water column bacterial population densities at water temperatures of ca. 19 C. Thus, temperature of the water column in the range of 14 to 19 C was found to be critical in the annual cycle of the vibrios. Interaction between sediment, water, and zooplankton was found to be essential in the natural estuarine ecosystem. Bacterial counts of zooplankton were found to be temperature dependent. The bacterial population associated with zooplankton was found to be predominantly on external surfaces and was specific, differing from that of the sediment. Vibrio spp. and related organisms comprised the total bacterial population associated with zooplankton in summer months. The ecological role of Vibrio spp., including V. parahaemolyticus, was found to be significant, with respect to their property of chitin digestion and in relation to the population dynamics of zooplankton in Chesapeake Bay.