Structural and functional properties of irradiated nuclear membranes at the air-water phase interface

The monolayer technique, the methods of electron microscopy and IR-spectroscopy were used to study isolated nuclear membranes of calf thymus cells. The data obtained permitted to study the relationship between structural disorders induced by irradiation of membranes, the changes in their functional status, and the role played by a lipid component of membranes in these processes.     

A new species of Dyrosaurus (Crocodylomorpha, Dyrosauridae) from the early Eocene of Morocco: phylogenetic implications

A new dyrosaurid is described from the Ypresian of the phosphatic deposits of the Oulad Abdoun Basin of Morocco. It is based on numerous cranial and postcranial remains, allowing an almost complete reconstruction. This new Dyrosaurus species, Dyrosaurus maghribensis sp. nov. , is currently only known from Morocco. It differs from D. phosphaticus , present in contemporaneous levels of Algeria and Tunisia, by several autapomorpies, including a smooth dorsal margin of the parietal and widely opened choanae. A phylogenetic analysis, using 47 taxa and 234 morphological characters, shows the dyrosaurids as the sister taxon of pholidosaurids, which include Elosuchus , Sarcosuchus , Terminonaris and Pholidosaurus , and the thalattosuchians. Goniopholididae is a non-monophyletic group; however, if dyrosaurids are not included in the analysis, the result differs and the goniopholidids form a distinct clade. If Thalattosuchia is excluded, both Goniopholididae and Pholidosauridae become paraphyletic assemblages. Thus, phylogenetic problems remain with respect to longirostrine clade, and more attention should be paid to resolving their evolutionary relationships amongst the crocodyliforms.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 603–656.     

The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) Prisons Project Study: protocol for a randomised controlled trial comparing methadone and buprenorphine for opiate detoxification

Many research-funding agencies now require open access to the results of research they have funded, and some also require that researchers make available the raw data generated from that research. Similarly, the journal Trials aims to address inadequate reporting in randomised controlled trials, and in order to fulfil this objective, the journal is working with the scientific and publishing communities to try to establish best practice for publishing raw data from clinical trials in peer-reviewed biomedical journals. Common issues encountered when considering raw data for publication include patient privacy – unless explicit consent for publication is obtained – and ownership, but agreed-upon policies for tackling these concerns do not appear to be addressed in the guidance or mandates currently established. Potential next steps for journal editors and publishers, ethics committees, research-funding agencies, and researchers are proposed, and alternatives to journal publication, such as restricted access repositories, are outlined.     

Sediment accumulation predicts the distribution of a unionid mussel (Elliptio complanata) in nearshore areas of a Canadian Shield lake

1. The importance of native freshwater mussels for ecosystem processes depends on their density, size distribution and activity. In lakes, many of the factors that affect mussels (fish hosts, habitat, food) could be directly or indirectly related to wind‐driven physical processes. 2. We tested whether the abundance and size of Elliptio complanata in the shallow, nearshore areas of a medium‐sized lake were related to site exposure, substratum type and fish distribution. To disentangle some of the correlated variables known to affect mussel distribution, we used paired exposed and sheltered sampling sites along the 7‐km fetch of the lake basin. 3. The distribution of sediment characteristics in nearshore areas was highly predictable. The mean depth of accumulated soft sediments decreased with increasing fetch at wind‐exposed sites, but increased with increasing fetch at sheltered sites. Sediments were deeper along the main shoreline than around islands. Deeper sediments tended to be finer and higher in silt content and organic fraction. 4. The density and proportion of juvenile mussels along the main shoreline varied in a unimodal way with sediment depth. These results suggest that wind‐driven physical forces affect the transport of young juveniles to sediment depositional areas and create sediment conditions that influence their growth and survival. In contrast, the proportion of juvenile mussels around islands was not related to sediment characteristics, but decreased with remoteness of the island, suggesting that the distribution of juvenile mussels may be limited by fish movements. These results are tentative since they do not include buried juvenile mussels. 5. We also found a unimodal relationship between total mussel density (juveniles and adults) and sediment depth but, in contrast to the relationship for juveniles only, it applied to all sites with soft sediments, including islands. We conclude that factors related to sediment depth affect the growth and survival of adult mussels around islands and that these factors are strong enough to modify the pattern of distribution established via dispersal during earlier life stages. 6. The mean shell length of adults at different sites within the lake basin ranged from 60 to 85 mm. Mussel shell length decreased with increasing fetch at sites exposed to the prevalent winds, but was relatively constant on the sheltered side of peninsulas and islands. The size of unionid mussels in different parts of the lake seems to be determined both by their exposure to physical forces and by sediments. 7. The local distribution of E. complanata is determined, directly and indirectly, by wind‐driven forces. These processes are likely to be important for other benthic organisms affected by similar habitat conditions (e.g. sediment characteristics, physical disturbance).     

Role of Aromatic Amino-acid Residues in the Binding of Enzymes and Proteins to Nucleic Acids

MANY studies have been made of the specificity of interaction between nucleic acids and polypeptides, proteins and enzymes^1,2. Electrostatic forces between basic amino-acids and phosphate groups contribute to the stability of the complexes, but selective recognition requires more specific interactions which are not yet understood. The recognition of a specific region of a nucleic acid could be explained if this region has some particular conformation or if there are specific interactions between a few amino-acid residues and the bases of this region. We wish to report results which show that the aromatic amino-acids tryptophan and tyrosine can interact with nucleic acid bases in double stranded nucleic acids. They suggest that aromatic amino-acid residues of enzymes and proteins could participate in the binding to nucleic acids by intercalating between the bases and thus constraining the nucleic acid molecule to adopt a definite position with respect to the protein molecule.     

Ultrastructural changes in the dendrites during aging

Dendrite ultrastructure was studied in different brain areas of old rats, aged 28-30 months. Different ultrastructural forms of the reactive and destructive processes in the dendrites, irregularity of their pathomorphological changes with ageing and greater destruction of large dendrites, as compared to small ones are demonstrated.     

Développement de la partie antérieure de la mandibule de Salmo trutta fario L. (Pisces, Teleostei, Salmonidae)

A study of the origin and development of the bony complex ("dentaire" s.l.) later forming the anterior part of the mandible of Salmo fario leads to the following conclusions: (1) various modes of ossifications occur in the ontogeny of this bony complex, (2) the main component is the dermal (dento-splénial) whereas the enchondral one (mentomeckelien) is much reduced, (3) the proposed term "dento-splénio-mentomeckelien" focuses attention, at the same time, on the order of appearance and relative importance of the two components.