Species 7. Cisticola Brunnescens. Pl. VII.

This third species of Cloud-scraper was first named by Dr. von Heuglin in 1862 from an adult male in Summer dress obtained by himself in Abyssinia. Later (in 1869), not realizing their specific identity, von Heuglin gave examples of the same species in Winter and juvenile dresses with different specific names, viz. iodopyga and habessinica , but did not have to contend with the difficulty of separating ayresii from brunnescens because the former species does not occur in Abyssinia. Elsewhere, from Kenya Colony to South Africa, that has always been the difficulty, and wherever the two species were subsequently found they were more or less indiscriminately related to one another as forms or allies of ayresii (under that bird's wrong name terrestris) , until, in 1913 *, Roberts showed the differences between them in South Africa, and, in 1922†, van Someren the same for Kenya Colony.     

Characteristics of two marine nitrite oxidizing bacteria,Nitrospina gracilis nov. gen. nov. sp. and Nitrococcus mobilis nov. gen. nov. sp.

Summary Two new nitrite oxidizing bacteria for which the names Nitrococcus mobilis and Nitrospina gracilis are proposed were isolated from the marine environment. Nitrococcus mobilis was cultured from South Pacific waters and it is a large motile coccus with unique tubular cytomembranes. Nitrospina gracilis was isolated from South Atlantic waters and it is a long slender rod which lacks an extensive cytomembrane system. Both are obligate marine organisms and both are obligate chemoautotrophs. The fine structure of these organisms is detailed.Contribution No. 2631 from the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543.     

Brachyptera Group. Sp.32. C. Brachyptera. Sp.33. C.c RUFA. Sp.34. C. Troglodytes. Sp.35. C. Fulvicapilla.

A part from considerations as to where it is best wedged into the linear sequence, the brachyptera group is defined in general terms as a compact group of four small or very small species which resemble one another in many important specific characters and the other thirty-six species classified here as Cisticola in so many ways of form, coloration and behaviour as to make them best understood by classifying them also under that generic name.     

Studies of metal-sugar complexes in the solid state by the 13C-n.m.r. c.p.-m.a.s. method

Several metal-sugar conjugates have been prepared. Chelate coordination complexes of copper(II) and zinc(II) were prepared from salicylaldimine ligands derived from combinations of methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-β-d-glucopyranoside or 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β-d-glucopyranose and salicylaldehyde. Similar Schiff's bases were prepared from chitosan and complexed to copper(II). Cross-polarisation-magic angle spinning ¹³C-n.m.r. spectroscopy showed that paramagnetic ions have profound effects on the resolution obtainable and, at high concentration, result in broad, featureless spectra. In contrast, diamagnetic ions have little effect on the isotropic chemical shifts of the sugar chelates.     

Species 29. Cisticola Carruthersi. Pl. XIV. fig. 59. Cisticola carruthersi O.-Grant, Bull. B. O. C. xxiii. 1909, p. 94: typ. loc. Mokia, L. George, Uganda.

The B. O. C. Ruwenzori expedition of 1906 brought home a single immature female of this species, obtained in a papyrus swamp near Lake George, and to Ogilvie-Grant's discrimination we owe the recognition of its specific distinction from galactotes , the species it so closely resembles in coloration, and which is certainly carruthersi s nearest ally.     

Agglutinability of cattle red cells. 3. Conglutination.

Addition of both complement and conglutinin was necessary to conglutinate the cattle red cells (CRC) when they were sensitized by different blood typing reagents. Although the degree of conglutinability of the CRC was influenced by the particular blood factor-reagent combination the average conglutinability (i.e. average titre scores) of CRC from different MZ pairs varied from 1.9 to 16.2. The titres of complement varied from zero to 1:32, while the titres of conglutinin ranged from 1:8 to 1:1024 in the different sera from MZ cattle twins. The variance due to differences in the titre scores between MZ pairs was 82.2% for conglutinin and 68.3% for complement. There was no evident association between the titres of conglutinin and complement.     

Plagiochila atlantica F. Rose,sp. nov.—P. amhagiosa auct.

Abstract

The Irish plant which, following Mitten, has commonly been referred to as Plagiochila ambagiosa Mitt. is specifically different from the type of P. ambagiosa, and is therefore described as Plagiochila atlantica F. Rose, sp. nov. It is now known from very restricted areas in Western Ireland, Western Scotland and North-western France.     

Radical formation in salts of pyrimidines. II. Cytosine. HCl crystals.

Radicals produced by X-irradiation at 77 K and at 300 K of cytosine. HCl crystals have been analysed by electron spin resonance spectroscopy. Four radicals have been identified: the anion radical of the cytosine molecule, the radical resulting from H-addition at position C6, the radical resulting from H-addition at position O2, and finally a radical resulting from addition of a Cl- to nitrogen N3. Hückel molecular orbital calculations are presented, which support the hypothesis according to which in unsaturated pyrimidines the site of hydrogenation or protonation depends on the state of the molecule.     

R.M. Cowling,D.M. Richardson & S.M. Pierce (eds.) 1977. Vegetation of Southern Africa.

We determined the role of bird dispersal in seed and seedling dynamics of the tree Kalopanax pictus from 7 years of observing seed rain and seedling emergence in a broad-leaved deciduous forest in central Japan. We also performed an experiment on the influence of seed pulp on germination of seeds of K. pictus. Seeds of this species can lie dormant for several years, and this causes rather constant yearly seedling emergence in spite of irregular seed production. The spatial distribution of the seedlings that emerged each year (maximum distance from nearest conspecific seed-bearing tree of 90 m) was wider than that of gravity-dispersed seeds (max. distance of 37 m), suggesting seed dispersal by birds in winter. Emerged seedling densities at sites over 20 m from the nearest conspecific seed-bearing tree were highest in the spring of 1991, about half a year after the largest seed fall of the observation period. However, emerged seedling densities within 20 m from seed-bearing trees were highest in 1992, 1.5 years after the largest seed fall. These field observations may be explained by the experimental results on the effects of seed pulp on germination. Intact seeds germinate slowly at low germination rates, while seeds without seed pulp germinate quickly at high germination rates. Fallen seeds with seed pulp thus appear to form a seed bank near seed sources (temporal dispersal), while seeds scattered by birds appear to increase the possibility of reaching the present safe sites in distant areas with quick germination (spatial dispersal).     

Chicken fumarase. I. Purification and characterization.

Fumarase from chicken heart is purified 400 times from the crude muscle extract. The isolation procedure includes ammonium sulfate fractionations, Bio-Gel P-300 column chromatography and electrofocusings on pH-gradients from pH 3 to 10 and from pH 7 to 9. Chicken fumarase behaves as an homogeneous protein in sedimentation, diffusion and electrofocusing studies; the protein possesses a single amino-terminal residue: lysine. The analysis of the CD and ORD spectra suggests the presence of 60-65 p. cent of alpha-helix, 0 - 5 p. cent of beta-structure with the remaining portions of the protein in an unordered conformation. Chicken fumarase is found to be composed of 4 subunits of identical molecular weight (51.000) and devoid of disulfide bridges. Finally, the physicochemical properties of chicken fumarase are compared with those of the porcine enzyme.     

Cryptosporidium canis n. sp. from domestic dogs.

Oocysts of Cryptosporidium, from the feces of a naturally infected dog and from an HIV-infected human, were identified as the previously reported canine genotype of Cryptosporidium parvum, hereafter referred to as Cryptosporidium canis n. sp. Also among the oocysts from the dog, a trace amount of C. parvum bovine genotype was detected. Cryptosporidium canis oocysts from both the dog and human were infectious for calves. Oocysts excreted by calf 1 (dog source) were approximately 90% C. canis and 10% C. parvum, whereas those excreted by calf 3 (human source) were 100% C. canis. Oocysts from calf 1 infected calf 2 resulting in excretion by calf 2 of oocysts approximately 90% C. parvum and 10% C. canis. Oocysts of C. canis were not infectious for BALB/c neonatal mice or immunosuppressed C57 juvenile mice, although all control mice became infected with the C. parvum Beltsville isolate. Oocysts of C. canis from calf 1 and the human were structurally indistinguishable from oocysts of the C. parvum Beltsville isolate (bovine). However, C. canis oocysts differed markedly at the molecular level from all known species of Cryptosporidium based on sequence data for the 18S rDNA and the HSP 70 gene. The differences in genetics and host specificity clearly differentiate C. canis as a new species.     

The nervous system of Loligo. II. Suboesophageal centres.

A well-marked hierarchy of centres can be recognized within the suboesophageal lobes and ganglia of the arms. The inputs and outputs of each lobe are described. There are sets of motoneurons and intermediate motor centres, which can be activated either from the periphery or from above. They mostly do not send fibres up to the optic or higher motor centres. However, there is a large set of fibres running from the magnocellular lobe to all the basal supraoesophageal lobes. The centre for control of the four eye-muscle nerves in the anterior lateral pedal lobe receives many fibres direct from the statocyst and from the peduncle and basal lobes, but none direct from the optic lobe. The posterior lateral pedal is a backward continuation of the oculomotor centre, containing large cells that may be concerned in initiating attacks by the tentacles. An intermediate motor centre in the posterior pedal lobe probably controls steering. It sends fibres to the funned and head retractors, and by both direct and interrupted pathways to the fin lobe. It receives fibres from the crista nerve and basal lobes, but none direct from the optic lobe. The jet control centre of the ventral magnocellular lobe receives fibres from the statocyst and skin and also from the optic and basal lobes. Some of these last also give extensive branches throughout the palliovisceral lobes. The branching patterns of the dendritic collaterals differ in the various lobes. Some estimates are given of the numbers of synaptic points. The dendritic collaterals of the motoneurons spread through large volumes of neuropil and they overlap. The incoming fibres spread widely and each presumably activates many motoneurons either together or serially. Many of the lobes contain numerous microneurons with short trunks restricted to the lobe, but there are none of these cells in the chromatophore lobes or fin lobes. The microneurons have only few dendritic collaterals, in contrast to the numerous ones on the nearby motoneurons.     

Chicken fumarase. II. Kinetic studies.

The catalysis of the hydration of fumarate and deshydration of L - malate by chicken fumarase was measured spectrophotometrically over a range of substrate concentrations from 4 times 10(-3) M to 8 times 10(-5) M for fumarate and from 8 times 10(-2) M to 10(-3) M for L - malate. For the forward and reverse reactions, linear Lineweaver and Burk plots were obtained. The Michaelis constants and the maximum initial velocities for both substrates were determined and the Haldane relation was found to be obeyed. The effect of pH on activity was investigated over a pH range from 5.5 to 9.0 and the data indicate the presence, in the active site, of two ionizable groups, one in the acidic form and one in the basic form. The values of the ionization constants, determined for the enzyme - substrate complexes, agree closely with the ones obtained for the porcine enzyme. The mode of action of twenty-four structural analogs on the initial velocity of the dehydration of L-malate, by chicken fumarase was examined. From these studies, two regions positively charged appear necessary for the effective binding of the carboxylates of the substrates and competitive inhibitors to the active center. Moreover, the data suggest the presence of an additional group, in the catalytic site of chicken fumarase, that stabilizes the carbon-carbon double bond common to fumarate and its structural analogs. Finally, from the comparison of the kinetic properties of the chicken and pig fumarases, it may be concluded that the catalytic mechanism of the homologous enzymes are very similar, if not identical.     

Cyanide inhibition of cytochrome c oxidase. A rapid-freeze e.p.r. investigation.

The inhibition of cytochrome c oxidase by cyanide, starting either with the resting or the pulsed enzyme, was studied by rapid-freeze quenching followed by quantitative e.p.r. It is found that a partial reduction of cytochrome oxidase by transfer of 2 electron equivalents from ferrocytochrome c to cytochrome a and CuA will induce a transition from a closed to an open enzyme conformation, rendering the cytochrome a3-CuB site accessible for cyanide binding, possibly as a bridging ligand. A heterogeneity in the enzyme is observed in that an e.p.r. signal from the cytochrome a3 3+-HCN complex is only found in 20% of the molecules, whereas the remaining cyanide-bound a3-CuB sites are e.p.r.-silent.     

N.m.r. and biochemistry

The role and historical progress of n.m.r. applications in biochemistry are briefly outlined. Technical advances over the years have made n.m.r., at last, a technique which can give valuable information about a wide range of biochemical topics, from enzyme kinetics in vivo to the structure of protein-DNA complexes. Emphasis here is placed on studies of proteins, especially those made up from mosaics of modules. It is shown that n.m.r. can readily give detailed structural information about individual protein modules and that valuable information about the structure and function of the intact mosaic protein can be inferred.     

Pohlia muyldermansii Wilcz. & Dem. var. pseudomuyldermansii var. nov., a new name for P. muyldermansii Wilcz. & Dem. sensu Lewis & Smith

Abstract

The results of a comparative study of Pohlia muyldermansii from Continental Europe and the British Isles are presented. Two varieties are recognized, var. muyldermansii from Belgium and the Netherlands and var. pseudomuyldermansii var. nov. from Great Britain, Ireland, Austria and Switzerland. P. camptotrachela is reported from Belgium and differences between this species and P. muyldermansii discussed.     

Staphylococcus cohnii subspecies: Staphylococcus cohnii subsp. cohnii subsp. nov. and Staphylococcus cohnii subsp. urealyticum subsp. nov.

Two major subspecies of Staphylococcus cohnii, namely S. cohnii subsp. cohnii, from humans, and S. cohnii subsp. urealyticum, from humans and other primates, are described on the basis of a study of 14 to 25 strains and 18 to 33 strains, respectively. DNA-DNA hybridization studies conducted in our laboratory in 1983 (W. E. Kloos and J. F. Wolfshohl, Curr. Microbiol. 8:115-121, 1983) demonstrated that strains representing the different subspecies were significantly divergent. S. cohnii subsp. urealyticum can be distinguished from S. cohnii subsp. cohnii on the basis of its greater colony size; pigmentation; positive urease, beta-glucuronidase, and beta-galactosidase activities; delayed alkaline phosphatase activity; ability to produce acid aerobically from alpha-lactose; and fatty acid profile. The type strain of S. cohnii subsp. cohnii is ATCC 29974, the designated type strain of S. cohnii Schleifer and Kloos 1975b, 55. The type strain of S. cohnii subsp. urealyticum is ATCC 49330.     

Human testicular cultures. II. Sertoli cells.

Two cell types, one epitheloid and the other fibroblast-like, were found in human testicular cultures derived from testes of patients. Ultrastructural studies indicated that, whereas the epitheloid cells were Sertoli cells, the fibroblast-like cells were fibroblasts. The Sertoli cells could maintain growth for a period of more than 4 months. In cultures derived from normal testes, only fibroblasts were observed.     

The teichuronic acid from the walls of Bacillus licheniformis A.T.C.C. 9945.

The teichuronic acid of Bacillus licheniformis A.T.C.C. 9945 grown under phosphate limitation was isolated from the cell walls and purified by ion-exchange and Sephadex chromatography. The detailed structure of the polysaccharide was established by methylation analysis, periodate oxidation and partial acid hydrolysis. The polymer is composed of tetrasaccharide repeating units with the structure [GlcA beta(1 leads to 4)GlcA beta(1 leads to 3)GalNAc beta(1 leads to 6)GalNAc alpha(1 leads to 4)n. 13C n.m.r. analysis has confirmed most of the structural features of the polysaccharide and, in particular, the anomeric configurations and linkage positions of substituents. The teichuronic acid from glucose-limited cells was identical with that from cells grown under phosphate limitation.     

Somaclonal variation inLolium multiflorum L. andL. temulentum L.

Tiller-derived callus ofLolium multiflorum L. gave rise to 65 regenerants displaying variation in height, flowering time, chromosome number and alteration to the banding pattern of the isoenzyme superoxide dismutase. Plants were also regenerated from callus cultures initiated from immature embryos of the related inbreeding speciesLolium temulentum L. Progeny of the regenerated plants from this species displayed variation in height, flowering date, ear length and chlorophyll content.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - BAP 6-benzylaminopurine