Phylogenetic relationships of Blepharisma americanum and Colpoda inflata within the phylum ciliophora inferred from complete small subunit rRNA gene sequences

The complete small subunit rRNA gene sequences of the heterotrich Blepharisma americanum and the colpodid Colpoda inflata were determined to be 1719 and 1786 nucleotides respectively. The phylogeny produced by comparisons with other ciliates indicated that C. inflata is allied more closely with the nassophoreans and oligohymenophoreans than the spirotrichs. This is consistent with the placement of the colpodids in the Class Copodea. Blepharisma americanum was not grouped with the hypotrichs but instead was placed as the earliest branching ciliate. The distinct separation of B. americanum supports the elevation to class status given the heterotrichs based on morphological characters.     

A comparison of lipoprotein lipase activity and adipocyte differentiation in growing male rats.

During adipose tissue development changes in lipoprotein lipase activity per adipocyte precede significant changes in fat cell size. Lipoprotein lipase activity per adipocyte increases fourfold from the second to seventh postnatal week. Furthermore, when isolated adipocytes and stromal--vascular cells are prepared by collagenase digestion of adipose tissue, there is a progressive shift in enzyme activity during development from the stromal-vascular compartment to the adipocyte fraction. The data support the concept that during normal development a "bed" of preadipocytes is synthesized during the suckling period. The data further suggest a regulatory role for lipoprotein lipase in the control of "lipid-filling" during early postnatal development.     

The mitochondrial complex in cryptophyceae

The unitary nature of the mitochondrion and the characteristic flattened finger-like morphology of the cristae were demonstrated in the Cryptophyceae. Hemiselmis rufescens contained an unbranched vermi-form mitochondrion in contrast to the variously branched complex, comprising an interconnected peripheral and central reticulum, in Chroomonas sp. and strains of Cryptomonas. The systematic value of the shape and distribution of the mitochondria in the examined genera was suggested.     

The influence of snow conditions on the date of breeding of wading birds in north-east Greenland

The young of wading birds that breed in some parts of the arctic hatch when their insect food supply is most abundant. This appears to be the ultimate factor determining the date of egg-laying. In various other arctic birds the date of breeding may be influenced, directly or indirectly, by the time at which snow or ice melts. The Joint Biological Expedition to N.E. Greenland 1974 studied Ringed plovers Charadrius hiaticula , Dunlins Calidris aplina , Sanderlings Calidris alba , Knots Calidris canutus , and Turnstones Arenaria interpres breeding in various areas within 80 km of each other.
In 1974 the thaw was two or three weeks later than normal in the region. The time at which snow cleared and the dates of breeding of the waders differed considerably between valleys: breeding was delayed in valleys that cleared late. In all areas egg-laying ceased early in July, probably because chicks hatching from eggs laid later would not be ready to migrate by the end of the summer. Hence the mean date and length of the egg-laying period were determined by the date of snow clearance from the breeding areas.
Studies of the potential food resources indicate that the waders in N.E. Greenland do not appear to time their breeding so that the young hatch at some peak of food abundance. Sufficient food resources are probably available over a long period of time.     

Distribution and behaviour of Acetes sibogae Hansen (Decapoda, Crustacea) in an estuary in relation to tidal and diel environmental changes

Quantitative samples of Acetes sibogae were collected at 2 hintervals for 48 h at three sites across the axis of a tidalestuary to examine their distribution within the water bodyover tidal and diel cycles, and to assess the role of behaviourin maintaining population distribution in estuarine/coastalwaters in relation to selected environmental factors. Watertemperature, salinity, tidal height and light intensity wereconcurrently measured. Distribution of the shrimp across theestuary was uniform and consistent between daylight or darkperiods, and among flood or ebb tides. Changes of A.sibogaeabundance were related to light and tidal cycles at each sitewith higher catches in dark periods and during flood tides.Acetes sibogae also exhibited both nocturnal and tidal verticalmovements in the water body, with greater numbers being onlyfound near-surface rather than near-bottom during flood tidesand at night. No significant differences in the distributionof size groups were found between any sampled levels of anysite. Acetes sibogae was highly aggregated in the water body.It is suggested that aggregating behaviour and tidal and nocturnalvertical movements act to facilitate population maintenancein estuarine/coastal waters.     

Studies on the binary and ternary complexes formed by a neurospora glutamate dehydrogenase and its substrates

The NADP⁺ specific glutamate dehydrogenase from wild-type $\text{Neurospora crassa}$ forms a stable binary complex with NADPH. This can combine with L-glutamate, α-ketoglutarate or the substrate analogue D-glutamate to form ternary complexes which can be distinguished by their different fluorescence properties. The affinity of the enzyme for NADPH diminishes with increases in pH or ionic strength of the solution. Experimental data obtained using modified glutamate dehydrogenases from mutant strains of $\text{N. crassa}$ suggest that the reduced-coenzyme binding sites observed fluorimetrically are the same as those observed by enzyme kinetics.     

A purification procedure for the soluble cytochrome oxidase and some other respiratory proteins from Pseudomonas aeruginosa.

The production of the soluble cytochrome oxidase/nitrite reductase in the bacterium Pseudomonas aeruginosa is favoured by anaerobic conditions and the presence of KNO3(20g/l) in the culture medium. Of three methods commonly used for the disruption of bacterial suspensions (ultrasonication, liquid-shear homogenization and glass-bead grinding), sonication proved the most efficient in releasing the Pseudomonas cytochrome oxidase. A polarographic assay of Pseudomonas cytochrome oxidase activity with sodium ascorbate as substrate and NNN'N'-tetramethyl-p-phenylenediamine dihydrochloride as electron mediator is described. A purification procedure was developed which can be used on the small scale (40-litre cultures) or the large scale (400-litre cultures) and provides high yields of three respiratory-chain proteins, Pseudomonas cytochrome oxidase, cytochrome c551 and azurin, in a pure state. A typical preparation of 250g of Ps.aeruginosa cell paste yielded 180mg of Pseudomonas cytochrome oxidase, 81 mg of Pseudomonas cytochrome c551 and 275mg of Pseudomonas azurin.