Thermal responses and temperature tolerance of a dessert ant-lion larva

1. 1.Cueta trivirgata larvae construct pits in the dry Kuiseb River bed in the Namib Desert.

2. 2.An art, Ocymyrmex robustior comprises 65.4% of the biomass of prey consumed by the ant-lions.

3. 3.O. robustior is active between surface temperatures of 27–68°C.

4. 4.Ant-lions tolerate high body temperatures (LD₅₀ = 53.4°C).

5. 5.By exploiting the pit microclimate and by digging below the surface during extreme thermal loads, ant-lions can capture prey at surface temperatures of 13–63°C.

6. 6.These behavioural and physiological adaptations enable ant-lions to maximize the duration of vigilance and hence prey capture success.

A national survey of airborne pollen and grass flowering in New Zealand,with implications for respiratory disorder

Airborne pollen and spore levels were monitored at seven sites in New Zealand using the Intermittent Cycling Rotorod sampler during the summer of 1988/1989. Grasses formed the major component of atmospheric pollen levels during spring and summer at every locality. Peak levels of grass and total pollen occurred during December or late November, with a slight latitudinal lag apparent at the more southern sites. Highest levels were recorded at the smaller rural centres of Gore and Kaikohe and the lowest at the larger urban centres of Auckland, Christchurch and Wellington. We make a first approximation of the likely risk to hayfever and allergic asthma patients at each of the seven centres. For example, significantly higher grass pollen levels were experienced at Kaikohe on 44% and 65% of days during November and December, compared with just 15% and 8% at Auckland. By recording the flowering seasons of the principal allergenic grass species at each locality, we determined the potentially allergenic grasses contributing to peak pollen levels, the most ubiquitous being tall fescue (Festuca arundinacea Schreb.), ryegrass (Lolium perenne L.,L. multiflorum Lam.), cocksfoot (Dactylis glomerata L.), Yorkshire fog (Holcus lanatus L.) and sweet vernal (Anthoxanthum odoratum L.). Corresponding author. Deceased.     

An analysis of substrate binding interactions in the heme peroxidase enzymes: A structural perspective

The interactions of heme peroxidase enzymes with their substrates have been studied for many years, but only in the last decade or so has structural information begun to appear. This review looks at crystal structures for a number of heme peroxidases in complex with a number of (mainly organic) substrates. It examines the nature and location of the binding interaction, and explores functional similarities and differences across the family.     

Endothelin-3 reduces C-type natriuretic peptide-induced cyclic GMP formation in C6 glioma cells

The effect of endothelin-3 (ET-3) on C-type natriuretic peptide (CNP)-induced guanosine 3′,5′-cyclic monophosphate (cGMP) was examined in C6 glioma cells, CNP-induced cGMP formation was both time- and dose-dependent, with an EC₅₀ value of about 10 nM. While ET-3 and phorbol 12-myristate 13-acetate (PMA) had no effect on basal cGMP production, both compounds were potent inhibitors of CNP-induced cGMP formation, with IC₅₀ values of approximately 10 and 2 nM, respectively. Although protein kinase C (PKC) inhibitors had no effect on basal cGMP formation, Ro 31-8220, a PKC inhibitor, reversed the ET-3 inhibition on CNP-induced cGMP formation by 63% and that of PMA almost completely. Our findings suggest that stimulation of cGMP formation by CNP in C6 glioma cells is negatively modulated by PKC activation, and that the inhibitory action of ET-3 on CNP-stimulated cGMP formation is mediated partly by PKC.     

Assessing the status of the marsh fritillary butterfly (Eurodryas aurinia): an example from Glamorgan, UK

We surveyed populations of Eurodryas aurinia (a butterfly listed as Threatened in Europe) in Glamorgan (South Wales, UK). The survey may provide a model for similar work, which is urgently needed throughout the species' European range. For each colony, we established population size, vegetation types, and current management regimes. Populations were assessed using larval surveys, a method which has several advantages over conventional adult surveys. With approximately 35 local populations, Glamorgan is among the most important areas for E. aurinia in the UK, and is of importance in a European context. However, 15 local populations were under immediate threat from unfavourable management or industrial developments, and only seven populations were on Sites of Special Scientific Interest. Colonies showed a clustered pattern, and varied greatly in size: 50% supported 20 or fewer larval webs. Many of the small populations may be temporary offshoots of larger, more permanent populations nearby. The largest local populations occupied Molinia caerulea - Cirsium dissectum fen meadow habitats (National Vegetation Community M24), which were unmanaged, grazed by cattle, horses or ponies, or subject to periodic burning. Detailed local surveys such as this one, which assess the relative sizes of populations and the impact of current management practices, may be the best way to plan future conservation measures for E. aurinia.