Suitability of European climate for the Asian tiger mosquito Aedes albopictus: recent trends and future scenarios

The Asian tiger mosquito (Aedes albopictus) is an invasive species that has the potential to transmit infectious diseases such as dengue and chikungunya fever. Using high-resolution observations and regional climate model scenarios for the future, we investigated the suitability of Europe for A. albopictus using both recent climate and future climate conditions. The results show that southern France, northern Italy, the northern coast of Spain, the eastern coast of the Adriatic Sea and western Turkey were climatically suitable areas for the establishment of the mosquito during the 1960–1980s. Over the last two decades, climate conditions have become more suitable for the mosquito over central northwestern Europe (Benelux, western Germany) and the Balkans, while they have become less suitable over southern Spain. Similar trends are likely in the future, with an increased risk simulated over northern Europe and slightly decreased risk over southern Europe. These distribution shifts are related to wetter and warmer conditions favouring the overwintering of A. albopictus in the north, and drier and warmer summers that might limit its southward expansion.     

Short-term storage of cane toad (Bufo marinus) gametes

The responses of cane toad (Bufo marinus) gametes, used as a model for the development of assisted reproduction techniques for rare and endangered amphibians, to short-term storage at temperatures > 0 degrees C were studied. Whole excised testes were stored at 0 degrees or 4 degrees C for 15 days, and sperm motility was measured at excision and after storage for 2, 5, 7, 10, 12 and 15 days. Spermatozoa showed > 50% motility for 7 days at 0 degrees C and for 5 days at 4 degrees C. At 15 days, only spermatozoa stored at 0 degrees C still showed some motility (3%). Sperm suspensions were prepared at 5 day intervals over 30 days in simplified amphibian ringer (SAR) at dilutions of 1:1, 1:5 and 1:10 (w/v) testes:SAR. Aliquots from each dilution were stored at 0 degrees C in Eppendorf tubes opened at 5 day intervals of storage (aerated) or kept sealed (unaerated) (treatments: aerated or unaerated; 5, 10, 15, 20, 25 and 30 days storage). After 30 days, sperm motility and fertilizing capacity were determined. The optimal protocol for sperm storage up to 10 days, as assessed by the retention of fertilizing capacity, was as a 1:5 testis:SAR (w/v) suspension, whereas the longest absolute retention of both motility and fertilizing capacity was observed in concentrated (1:1 dilution), anaerobic suspensions (up to 25-30 days). Oviductal oocytes placed in SAR at 5, 10, 15, 20 and 25 degrees C immediately after ovulation lost viability when cooled rapidly to 5 degrees C and stored for 2 h. However, oocytes retained viability for up to 8 h at the optimum storage temperature of 15 degrees C. Thus, it is concluded that during short-term storage spermatozoa retain viability for longer than oocytes, and that spermatozoa in suspensions retain viability for longer than spermatozoa stored in situ in excised testes.     

Financing for wind energy

This paper outlines the method used in Northern Ireland to finance the generation of electricity from renewable sources in general and wind power in particular.     

Activation of platelets exposed to shear stress in the presence of smoke extracts of low-nicotine and zero-nicotine cigarettes: the protective effect of nicotine.

Mainstream and sidestream smoke extracts of both high-tar and low-tar cigarettes have been shown to increase platelet activation directly and to sensitize them to further activation by exposure to mechanical stimuli such as shear stress. However, nicotine has an inhibitory effect on platelet activation, opposite to that of whole cigarette smoke extracts. To distinguish between the nicotine-dependent and non-nicotine-dependent effects of smoke, platelets were exposed to mainstream and sidestream smoke extracts of low-nicotine and zero-nicotine cigarettes in vitro under flow conditions comparable with the normal circulation, and their activation state was measured using a modified prothrombinase-based assay. Both low-nicotine and zero-nicotine extracts caused increased platelet activation upon exposure to shear stress, and they caused significantly greater activation than extracts from ordinary high-tar, high-nicotine cigarettes. That nicotine was crucial was confirmed by adding 50 nM nicotine (comparable with the nicotine level in smokers' plasma) to zero-nicotine smoke extracts and demonstrating a reduction in the shear-dependent rate of platelet activation of more than 75%.     

23—THE TRANSMISSION OF HEAT THROUGH TEXTILE FABRICS. PART III. A NEW THERMAL-TRANSMISSION APPARATUS

Details are given of a new thermal-transmission apparatus which is automatic in operation, which does not depend on the measurement of a heat flux, and which requires no guard plates to eliminate edge heat losses.

The apparatus works on the principle that for conductors in series with respect to direction of heat flow, the ratio of the temperature drop across them equals the ratio of their thermal resistances, and the only measurements involved are those of temperature in the equilibrium state.

The apparatus is suitable for testing the thermal-transmission properties of textile materials up to at least 1 in. thick. Data are presented for the thermal-transmission properties of timber and of plate glass determined with the new apparatus.     

Local Settlement in Woodland Birds in Fragmented Habitat: Effects of Natal Territory Location and Timing of Fledging

Factors such as early fledging and natal territory location have been shown to influence dispersal and settlement success of woodland birds. Early fledging allows for earlier dispersal, increasing the chances of an individual locating good quality habitat. However, for birds in fragmented woodland, the advantages of early dispersal may be modified by natal territory location in relation to the availability of suitable habitat in the surrounding landscape. Connecting habitat corridors may promote dispersal, and connectivity in landscapes is usually considered as positive, but this may not always be the case. In landscapes where habitat is highly fragmented, corridors may promote departure, but leaves dispersers with little chance of success. An individual-based Spatially Explicit Population Model was used to investigate the effects of timing of fledging, natal territory location and proximity to potential dispersal corridors on local settlement rates. Modelling was based on both hypothetical and real woodlands and used marsh tit as an example woodland bird. For each modelled scenario, the number of young that settled was recorded for each territory, the overall results being expressed as the mean percentage settlement rate per territory. Territory location and edge effects were both found to influence dispersal and settlement rate. Fledging early clearly demonstrated a general advantage for local settlement success. However, territory location, in relation to the likelihood of dispersing out of the wood was found to interact with fledging order. Fledglings from internal territories had an advantage over those from edge territories and local settlement rate could be reduced by a location favourable to emigration. In general, the effect of exits was to reduce the settlement rate of early fledging young while that of later young tended to increase. In highly fragmented woodland, fledging late from a well-connected edge territory would appear to be the worst case scenario.