The activity and distribution of wheat bulb fly (Delia coarctata) (Diptera:Anthomyiidae) in cereal crops and over fallow land

The flight activity and local distribution of adult D. coarctata were studied on Rothamsted Farm during 1970-5 using several trapping methods. Changes in the activity and distribution of the flies were followed as the population aged, and in females these changes were associated with maturation of their eggs. Most females appeared to stay at their emergence sites in winter wheat until egg-laying started about 1 month later. They then dispersed and both sexes were found in previously uninfested cereals and grass as well as on fallow land where the eggs are laid. Flight occurred chiefly in the late afternoon and evening. The concentration of flies at their emergence sites for several weeks before egg laying could facilitate chemical control, provided the practical difficulties of application can be overcome.     

Brachiopod Shell Proteins: Their Functions and Taxonomic Significance

The calcareous shell of the Brachiopoda is interspersed withorganic material, chiefly protein and polysaccharide. The aminoacid compositions of these proteins reflect their geneticallycoded biosynthesis and are phylogenetically and taxonomicallyinformative. The taxonomic scheme based on protein data agreeswith the scheme based on morphological and anatomical criteria.These findings indicate Crania occupies an anomolous position. Brachiopoda exhibit two main types of calcification, carbonateand phosphate. The hydroxyproline found in phosphatic inarticulateshell protein suggests an analogy with bone collagen, but theglycine content is too low to allow triple-helix formation. The number and nature of polypeptide chains making up the shellproteins have been determined by amino and carboxy end-groupanalysis as well as disc electrophoresis with SDS. In the nativestate the shell proteins are molecular aggregates and are dissolvedby 8 M urea, suggesting that the inter-chain links are largelyH–bonds. Articulate shell protein probably serves as a resilient cushioningbetween calcite fibers to protect against mechanical shock.This would be permitted by the amorphous flexible characterof the polypeptide chain. The shell proteins of the Inarticulataare different,their chitin-protein laminated shell is more sheet-likeand its structure requires less cushioning. Study of fossil protein can shed further light on shell proteinancestry and hence on brachiopod phylogeny.     

FINDING AUTONOMY IN BIRTH

Over the last several years, as cesarean deliveries have grown increasingly common, there has been a great deal of public and professional interest in the phenomenon of women 'choosing' to deliver by cesarean section in the absence of any specific medical indication. The issue has sparked intense conversation, as it raises questions about the nature of autonomy in birth. Whereas mainstream bioethical discourse is used to associating autonomy with having a large array of choices, this conception of autonomy does not seem adequate to capture concerns and intuitions that have a strong grip outside this discourse. An empirical and conceptual exploration of how delivery decisions ought to be negotiated must be guided by a rich understanding of women's agency and its placement within a complicated set of cultural meanings and pressures surrounding birth. It is too early to be 'for' or 'against' women's access to cesarean delivery in the absence of traditional medical indications – and indeed, a simple pro- or con- position is never going to do justice to the subtlety of the issue. The right question is not whether women ought to be allowed to choose their delivery approach but, rather, taking the value of women's autonomy in decision-making around birth as a given, what sorts of guidelines, practices, and social conditions will best promote and protect women's full inclusion in a safe and positive birth process.     

Nuclear sequences reveal mid-range isolation of an imperilled deep-water coral population

The mitochondrial DNA of corals and their anthozoan kin evolves slowly, with substitution rates about two orders of magnitude lower than in typical bilateral animals. This has impeded the delineation of closely related species and isolated populations in corals, compounding problems caused by high morphological plasticity. Here we characterize rates of divergence and levels of variation for three nuclear gene regions, then use these nuclear sequences as markers to test for population structure in Oculina , a taxonomically confused genus of corals. Rates of sequence divergence (obtained by comparison to Solenastrea hyades ) were at least five (and sometimes over 10) times faster for the three nuclear markers than for a mitochondrial reference sequence. Nuclear sequence variation was also high within populations, although it tended to decline north of Cape Canaveral. Significant subdivision was evident among samples from 10 locations from between North Carolina and the Florida Panhandle, but neither nominal species designation nor population depth explained much of this variation. Instead, a single population from the unique deep (> 70 m) water reefs at the Oculina Banks off central Florida was a strong genetic outlier: all pairwise measures of subdivision involving this population were greater than those involving all other populations, and multilocus clustering recognized the Oculina Banks as distinct from other populations, despite its close proximity (≤ 36 km) to populations from shallower waters nearby and its location at the centre of the sampled range. Genetic isolation of the Oculina Banks population suggests that focused efforts will be needed to conserve the foundation species of these monotypic reefs and that depth may play a role in isolating marine populations and perhaps facilitating initial steps towards speciation.     

Hydra size and budding rate: influence of feeding

Summary

In the present study of Dugesia tigrina, the development of the nervous system is followed and compared during regeneration after fission and after decapitation. Immunocytochemistry was used, with antisera raised against the biogenic mine, 5-hydroxyhyptamine (5-HT) and the two neuropeptides, neuropeptide F (NPF), and FMRFamide. The results indicate that two processes are involved in the formation of the new cerebral ganglion. First, new processes sprouting from the original main longitudinal nerve cords bend transversely, indicating the position of the developing horseshoe-shaped anterior cerebral commissure. Then new nerve cells in front of the commissure differentiate from neoblasts and their growth cones fasciculate with the fibres from the old main longitudinal nerve cords. In the cerebral ganglion, 5-HT-IR cells appear before NPF-IR cells, in contrast to the pharynx where NPF-IR cells differentiate before the 5-HT-IR cells. In the peripheral nervous system, NPF-IR fibres and cells appear at a very early stage and dominate the whole regeneration process. A role for the PNS in early pattern formation is suggested.