The structure of the plankton community of the Öregrundsgrepen (southwest Bothnian Sea)

Taxonomic composition and variations in density and biomass of the plankton community in the Öregrundsgrepen, a shallow coastal area, were investigated from June 1972 to November 1973. The phytoplankton biomass was large in spring but small during the rest of the year. The spring bloom was dominated by diatoms and dinoflagellates, especially byThalassiosira spp. which were also important during other seasons. Small forms, such asCryptomonas spp.,Rhodomonas spp. and monads, dominated during summer. Blue-green algae were never of any major importance. During the summer, the trophogenic layer exceeded 10 m in thickness. The metazoan fauna was of lower diversity than the plankton flora. The dominating species, the copepodsAcartia bifilosa andEurytemora affinis, constituted on the average 83% of the standing crop. The low salinities, 5–6 S, were regarded as the principal pertinent limiting factor. The metazoan fauna reached large biomass values from July to October. The protozoan fauna (in the case of ciliates), obtained biomass maxima during the spring bloom. It is suggested that the Öregrundsgrepen represents an area of elevated productivity within a region of low overall production, presumably due to local upwelling. From June 1972 to May 1973, the average biomasses were: phytoplankton 0.464 g C m^–2, ciliates 0.040 g C m^–2, copepod nauplii 0.010 g C m^–2, micro-rotifers 0.004 g C m^–2, and mesozooplankton (larger than 0.2 mm) 0.312 g C m^–2. It is estimated that about than 60% of the phytoplankton production is consumed by the microzooplankton (<0.2 mm).     

The phenomenon of conglomerate crystallization. XV. Spontaneous resolution in coordination compounds. XIII. The crystallization behaviour and the crystal and molecular structure of Δ(λδ)-cis-Rh(en)2(NO2)2]Cl

The title compound, I, crystallizes in the monoclinic space group P2₁ with cell constants: a = 6.599(3), b = 11.121(2), c = 8.375(1) Å and β = 106.35(2)°; V = 589.74 ų and D(calc; Z = 2) = 1.974 g cm⁻³. The compound is isomorphous and isostructural with its Co analogue. A total of 2982 data were collected over the range of 4°  20  70°; of these, 2537 (independent and with I ⩾ 3σ(I)) were used in the structural analysis. Data were corrected for absorption (μ = 16.6 cm⁻¹) and the relative transmission coefficients ranged from 1.000 to 0.9504. Refinement was carried out for both enantiomeric configurations and the crystal used was found to contain cations with Δ(λδ) absolute configuration. The final R(F) and R_w(F) residuals were, respectively 0.0220 and 0.0239 for (−−−; i.e.Δ(λδ)) and 0.0231 AND 0.0317 FOR (+++; i.e.Λ(δλ)). Thus, the former was selected as correct for our specimen.In the case of I, as well as in the Co derivative [cis-Co(en)₂(NO₂)₂]Cl (II), the conformation of one of the rings is opposite that expected for the lowest energy conformation, which in the current case should be Δ(λλ)).The RhN(NO)₂ distances are 2.020(2) and 2.010(2) Å, while the RhN(amine) distances, trans to the NO₂ ligands are 2.085(2) and 2.093(1) Å, values distinctly longer than the other two RhN distances (2.064(1) and 2.068(1) Å). The latter are the RhN distances to the terminalNH₂ ligands located trans to each other. Thus, we observe a trans effect, which is more pronounced in I than in II, and which is of comparable magnitude to that observed in the case of the trien derivative, [cis-α-Rh(trien)(NO₂)₂]Cl(III).Parallel with an increase in metalN distances in going from [cis-α-Co(trien)NO₂)₂]Cl·H₂) (IV) to (III) is an increase in the torsional angles of the outer rings (NCCN) of about 10°. Comparison of these parameters in I and II reveal that this change is not so marked for this pair since in I they are −54.9° and 52.8° while in II they are 50.2° and −48.1°; i.e. a change of only 4°. This important difference between trien and en derivatives is caused by the presence of the central five-membered ring, which for compounds III and IV remains largely unchanged, except for the metalN distances.The NO bond lengths are 1.244(3), 1.220)(2), 1.237(2) and 1.211(2) Å, which are similar to those found for the analogous Co isomer. The CN bond lengths are 1.492(3), 1.474(2), 1.486(2) and 1.475(2) Å, while the CC bonds are 1.509(3) and 1.524(3) Å. These values are also comparable with those obtained for the Co isomer and, in fact, the pattern of the bonds is nearly identical in both, including the common feature of having a longer CC bond for the en ring with the conformation opposite that expected.As was the case with the Co analogue, the Cl⁻ anion is associated with the hydrogens of the secondary nitrogen (trans to the −NO₂) ligands, the Cl…H7 distance being 2.18(3) Å and the <Cl…H7N2 = 163°.     

The peculiarities of nitrogen excretion in sturgeons (Acipenser ruthenus) (Pisces,Acipenseridae)—I. the influence of ration size

• 1.1. The nonfaecal nitrogenous excretion rate in starved sterlet fingerlings and fingerlings fed on different rations was investigated. The weight of the fish and temperature of the water was 43 g and 17.5°C, respectively.
• 2.2. In the nonfaecal excrements of starved sterlets the ammonia: urea ratio was substantially lower than in teleosts. This ratio was found to be 1.4:1.
• 3.3. In fed sterlets the urea excretion rate was higher than in starved ones but independent of ration size.
• 4.4. During the day the urea excretion rate in sterlets was constant.
• 5.5. The ammonia excretion rate accelerated 2 hr after feeding and reached its peak duration 6–11 hr after depending on the ration size.
• 6.6. Total ammonia output in the sterlet increased following the increase of ration size up to 8.4% of body wt. Further increases in ration size did not cause the corresponding elevation of ammonia excretion rate.

     

Somatic antigens of Pseudomonas aeruginosa. The structure of the O-specific polysaccharide chains of P. aeruginosa O11 (Lányi) lipopolysaccharides

Lipopolysaccharides were isolated from the phenol layer on aqueous phenol extraction of cells of Pseudomonas aeruginosa O11 (Lányi classification), strains 170021 and 170040. On mild acid degradation of the lipopolysaccharides, with the subsequent gel-filtration on Sephadex G-50, neutral O-specific polysaccharides made up of 6-deoxysugars alone were obtained. Two 2-acetamido-2,6-dideoxy-L-galactose (LFucNAc), 2-acetamido-2,6-dideoxy-D-glucose (DQuiNAc) and L-rhamnose (LRha) residues were found to be the components of the strain 170021 polysaccharide repeating units; those of strain 170040 contained the same monosaccharides, but, instead of 2-acetamido-2,6-dideoxy-D-glucose residue, that of 2-acetamido-2,6-dideoxy-D-galactose (DFucNAc) was present. On the basis of the 13C nuclear magnetic resonance data, methylation analysis and three successive Smith degradations the following structures were determined for the polysaccharide repeating units: strain 170021----2) LRha(alpha 1----3)LFucNAc(alpha 1----3)LFucNAc(alpha 1----3)DQuiNAc(beta 1----; strain 170040,----2)LRha(alpha 1----3)LFucNAc-(alpha 1----3)LFucNAc(alpha 1----3)DFucNAc(beta 1----; differing from one another by configuration of C-4 of 2-acetamido-2,6-dideoxy-D-hexopyranose only.     

The role of food in the population dynamics of Orchesella cincta (Linné) (Collembola)

Summary The feeding activity of the collembolan species Orchesella cincta (Linné) was studied in the laboratory and in the field. In the laboratory it was shown that at any one time only about 50–60% of the animals were feeding; the remainder were occupied with molting activities. Most of the time similar values were obtained in the field but during winter and during dry summer periods high percentages of empty guts could be demonstrated, indicating an absence or inaccessability of food. When favorable weather returned, a high feeding activity was again observed. Laboratory experiments and field observations indicate that temporary starvation periods are followed by synchronization of the molting and reproductive rhythms and an apparent increase in longevity. These phenomena are important for the restoration of the population after unfavorable periods but reduce the stabilizing force of food scarcity.     

The state of the art of biospeleology in Russia and other countries of the former Soviet Union: a review of the cave (endogean) invertebrate fauna. 1. Introduction—crustacea

At least 308 species or subspecies of stygo- or troglobionts and at least 735 species or subspecies of mostly presumed stygo- or troglophiles representing 17 phyla, 38 classes, 90 orders, and 278 families of invertebrates are currently known to populate the caves and subterranean waters of Russia and other countries of the former Soviet Union. The main evolutionary burst in the endogean habitats including the MSS (milieu souterrain superficiel, or mesovoid shallow stratum) is observed in arthropods, primarily crustaceans, collembolans, and beetles. The major centers of taxonomic diversity among stygo- and troglobionts within the study region are the Caucasus (181 species, or almost 59%) and Crimea (44 species, or over 14%), which are montane karstified “glacial” refugia of the nemoral biota. The contribution of the other major regions including karstified areas is considerably smaller and gradually decreases from Central Asia (35 species; over 11%), the Far East (33; nearly 11%), the Ukrainian Carpathians with Podolia (12; almost 4%), the Russian Plain (7; over 2%), the Urals and Ural region (7; over 2%) to Siberia (5 species; 1.6%). Inventorying remains a topical problem in assessing the stygo- and troglofaunas of the territories in question. The most complete bibliography possible is included.     

The Organization of the lamina ganglionaris of the prawn,Pandalus borealis (Kröyer)

The Lamina ganglionaris (first optic neuropile) of the decapod crustacean Pandalus borealis has its optic cartridges (synaptic compartments) arranged in horizontal rows. Each optic cartridge contains seven receptor axon terminals and the branching axis fibres of five monopolar second order neurons. Four types of monopolar neurons are classified. Their cell bodies are arranged in two layers. The inner layer contains the cell bodies of exclusively one of these types, and each cartridge is invaded by two neurons of this neuron type (type M 1:a and M 1:b). The outer layer contains the cell bodies of the remaining three types (M 2, M3 and M4). One gives rise to a large radially branched axis fibre in the centre of the cartridge. The other two have wide branches which may make inter-cartridge contacts, one proximally and the other distally in the plexiform layer, which is clearly bistratified. The receptor axons terminate in two levels corresponding to these strata. Two sets of tangenital fibres form networks in the proximal and the mid-portion of the lamina. Both networks have fibres with primary branches in the vertical plane and secondary branches in the horizontal plane. The fibres of the networks are derived from axons that pass from the second optic neuropile, the medulla externa.     

The Afromontane Cladocera (Crustacea: Branchiopoda) of the Rwenzori (Uganda–D. R. Congo): taxonomy,ecology and biogeography

The timely characterization of high-altitude freshwater habitats allows an assessment of the diversity of its biota and provides the basis for monitoring community change. In this study, we investigate the Cladocera fauna of 29 water bodies (pools, freshwater lakes, and surrounding swamps sampled at various occasions between 2005 and 2009) in the Rwenzori Mountains (Uganda, D. R. Congo), which are part of the East African Sky Island Complex. All sites except one are located above 3700 m altitude. We include notes on the morphology, taxonomy, distribution, and ecology of each recorded taxon and describe a new species of the Alona rustica-group (Alona sphagnophila n.sp.; Chydoridae). We found 11 species of which seven are restricted to Lake Mahoma, the lowest lake in our study area (2990 m) (Alona affinis barbata, A. intermedia, Alonella exisa, Alonella nana, Daphnia cf. obtusa, Pleuroxus aduncus) and/or Lake Bujuku (Daphnia cf. curvirostris, P. aduncus) (3900 m). Two taxa (Ilyocryptus cf. gouldeni, A. sphagnophila n.sp.) are restricted to Carex/Sphagnum bogs surrounding lakes in the afroalpine zone. Pigmented populations of Chydorus cf. sphaericus occur in all the sites. It is the only cladoceran species surviving the extreme alpine and nival conditions in the Rwenzori. The species is joined by A. guttata at locations at lower altitudes (ca. 3000–4000 m), present in about half of the sites. The Rwenzori Cladocera fauna is characterized by a strong extratropical temperate component and a low level of speciation/endemism. Harboring an impoverished boreal cladoceran community, Lake Mahoma is given closer attention. At 2990 m, the lake is a cold-temperate aquatic island in the tropics and may function as a stepping stone for Palaearctic taxa. We introduce a new term for high-altitude, cold-water habitats in the tropics, which act as climatic islands for extratropical freshwater faunas, Löffler Islands, in honor of Dr Heinz Löffler. In comparison to surveys in 1961, we list five new records in Lake Mahoma, which could indicate cladoceran community changes over the past few decades at ca. 3000 m in the Rwenzori. Since the species distributions correlate to temperature and catchment properties of the lakes, the Rwenzori cladoceran fauna can be expected as sensitive indicators for local changes.     

The twenty-fifth anniversary of the Limnological Institute,The Netherlands (1957–1982)

This paper marks the silver jubilee in 1982 of the Limnological Institute, The Netherlands. It describes the history, present research programme and organisation of the Institute, as well as its cooperative studies with other institutes and its training facilities.Some remarks about its future plans of work are made.     

The presence of N(ε)-(Carboxymethyl) lysine in the human epidermis

It is well known that advanced glycation end products (AGEs) are formed in long-lived dermal proteins such as collagen, and that their formation is related to skin aging. To examine the distribution of AGEs in skin tissue, we performed immunofluorescence studies on the human skin using an anti-AGEs antibody. Interestingly, AGEs signals were observed not only in the dermis but also in the epidermis. The objectives of this study were to confirm the presence of N(ε)-(Carboxymethyl) lysine (CML), an AGE structure, in the epidermis and to characterize the CML-modified proteins. The presence of CML in the stratum corneum (SC) was examined using liquid chromatography-electrospray ionization time-of-flight mass spectrometry. Concordance between the retention times of a compound in the SC hydrolysate and authentic CML, as well as with the specific mass transition of CML, was detected. This result showed that CML is present in the epidermis. In order to characterize the CML-modified proteins in the epidermis, protein samples extracted from the SC were analyzed using two-dimensional electrophoresis followed by an amino acid sequence analysis. The clarified peptide sequences covered approximately 27% of the amino acid sequences of cytokeratin 10 (K10). In the immunoblotting experiment following the two-dimensional electrophoresis, where protein samples extracted from whole epidermis were used, the position of the major CML-positive spots corresponded to those of K10. Taken together these results showed that CML is present in the human epidermis, and suggest that K10 is one of the target molecules for CML modification in the epidermis.     

Animal evolution. The end of the intermediate taxa?

Contrary to general belief, there has not been a reliable, global phylogeny of animals at hand within the past few decades. Recent progress in molecular phylogeny is rapidly changing the situation and has provided trees that constitute a reference frame for discussing the still controversial evolution of body plans. These trees, once purged of their possible artefacts, have already yielded confirmation of traditional, anatomically based, phylogenies as well as several new and quite significant results. Of these, one of the most striking is the disappearance of two superphyla (acoelomates such as flatworms, pseudocoelomates such as nematodes) previously thought to represent grades of intermediate complexity between diploblasts (organisms with two germ layers) and triploblasts (organisms with three germ layers). The overall image now emerging is of a fairly simple global tree of metazoans, comprising only a small number of major branches. The topology nicely accounts for the striking conservation of developmental genes in all bilaterians and suggests a new interpretation of the 'Cambrian explosion' of animal diversity.     

The growth of the grass pollen tube: 1. Characteristics of the polysaccharide particles (“P-particles”) associated with apical growth

Summary Numerous polysaccharide-rich particles (P-particles) occur in the tip region of growing grass pollen tubes, where they apparently contribute to the extending wall. In other families the corresponding bodies have been shown to originate from dictyosome activity during pollen tube growth. However, in the grasses the main synthesis precedes anthesis; the P-particles represent up to 30% of the reserves of the vegetative cell of the dormant grain, numbering over one million in the pollen grain of rye. Their membranes are incomplete. The polysaccharide content, which is initially coarsely granular but becomes microfibrillar with hydration, is readily extracted with ammonium oxalate, and is probably pectic in nature. Simple methods for isolating the particles in relatively pure populations are described. Hydrolysis yields principally galactose, arabinose, glucose, and rhamnose. Apart from proteins derived from the original bounding membranes, a protein fraction is tenaciously bound to the polysaccharide. Isolated P-particles move anodically in an electrical field, and the possibility that their movement from the grain to the tube tip during growth depends on a potential gradient, already demonstrated for lily pollen tubes, is considered.     

The morphology and fine structure of the colourless colonial flagellate Anthophysa vegetans (O. F. Müller) Stein

A strain of Anthophysa vegetans (O. F. Müller) Stein (Chrysophyceae or Chrysomonadida) was grown in culture and examined in detail by light and electron microscopy. It was shown to be a typical, though apochlorotic, member of its class; features of interest include a well-developed leucoplast and a starch-like reserve product. Aspects of the largely inorganic stalk are also discussed.     

Method of fixing the heterotic effect—implementation on plants (on the hundredth anniversary of the birth of V.A. Strunnikov)

The article is devoted to the 100th anniversary of the outstanding world-renown Russian scientist Vladimir Alexandrovich Strunnikov, Academician, Professor, Head of Group of Developmental Cytology and Sex Regulation at Koltzov Institute of Developmental Biology and Head of genetic studies on silkworms in a number of sericulture institutes in CIS. Laureate of the State Prize of the USSR (1981), Hero of Socialist Labor (1990), awarded the I.I. Mechnikov Gold Medal, Academy of Sciences of the USSR (1981), founder of the theory explaining the origin of heterosis. One of his most significant achievements is the “Methods of Fixing the Heterosis Effect,” which makes it possible to abandon the production of hybrid seed and increase the yield of many crops by 20–50%. Fixing the gene complexes that determine the heterosis effect will become the “springboard” that will allow obtaining even more productive heterotic hybrids on the basis of new-generation varieties. The efficiency of this method in plant objects at the organismal and molecular levels was shown in the All-Russia Research Institute of Rice. A modification of this method reducing its laboriousness and increasing its efficiency was developed.