137Cs and 40K in the terrestrial vegetation of the Yenisey Estuary: landscape, soil and plant relationships

Plant species, forming important components of Arctic food chains and of interest from a monitoring perspective, were studied at 36 plots representing flood plain and terrace landscapes of the Yenisey River and Estuary from its upper delta to the gulf. (137)Cs contamination densities at the plots varied from 0.35kBq/m(2) (central delta, sandy riverside plot) to 88kBq/m(2) (the upper delta plot) indicating both global and regional sources of anthropogenic pollution. Cs-137 levels in plants were within the range expected from global fallout inputs and varied from 31 to 140Bq/kg d.w. increasing in dominant groups in the order: grasses相似文献   

Cs-137 in Arctic foxes (Alopex lagopus) on Svalbard

This study presents 137Cs muscle activity concentrations in Arctic foxes (Alopex lagopus) from Svalbard over a period of several years and discusses the transfer of 137Cs to Arctic foxes through likely predator--prey relationships. Mean 137Cs activity concentrations and 137Cs Tag values (per trapping season) ranged from 0.51+/-2.76 to 1.32+/-2.89 Bq/kg (w.w.) and 5.1 x 10(-4) to 1.3 x 10(-3)m(2)/kg, respectively. Mean concentration ratios of 137Cs in Arctic foxes compared to probable prey ranged from 1.0 to 7.9. On Svalbard, transfer of 137Cs to Arctic foxes is likely to occur via both marine and terrestrial food chains. The relative contribution of marine and terrestrial food sources to the diet of Arctic foxes may vary by location and by season and may lead to either an increase or decrease in the trophic transfer of 137Cs to Arctic foxes compared to transfer resulting from terrestrial only diets.     

Delineating protected wildlife corridors with multi‐objective programming

Protected wildlife corridors can help counteract habitat fragmentation and link isolated reserve “islands” into connected reserve systems. The need for wildlife corridors will grow as expanding human populations place increasing pressure on remaining undeveloped land. A two‐objective zero–one programming model is formulated for the problem of selecting land for a system of wildlife corridors that must connect a known set of existing reserves or critical habitat areas. This problem is modeled as a network Steiner tree problem, under the objectives of minimizing corridor land costs and minimizing the amount of unsuitable land within the corridor system. Linear programming is used to find exact solutions with little or no branching and bounding, and the multi‐objective weighting method is used to generate non‐inferior alternatives. Two hypothetical examples demonstrate the model and solution procedure. Results can help inform planning and decision making for protected area land acquisition and habitat restoration.     

Pilot see,pilot do: Examining the predictors of pilots’ risk management behaviour

Decision-making under uncertainty, known as risk management, is common in many professions including medicine and the military. Within general aviation, it is a skill that pilots are largely expected to acquire through experience. This study sought to determine if there are known markers (i.e., attitude and risk perception) and or personal characteristics (i.e., flight experience and age) that predict the acquisition and utilization of this skill. Fifty-six participants were presented with a risky flight which involved searching for a wayward parachutist with minimal fuel on board their aircraft. A clear distinction in terms of ‘risk perception’ was evident between those pilots who elected to undertake the risky flight (36 participants) and those pilots who did not (20 participants). There was also evidence of attitudinal and demographic differences between the two groups. The results have implications for the selection and training of pilots.