Sex differences in the consequences of maternal loss in a long-lived mammal, the red deer (Cervus elaphus)

In several primates, the presence of mothers affects the growth, survival and reproduction of their offspring, but similar effects have not yet been demonstrated in ungulates. Here, we investigate the effects of the mother’s presence in a population of red deer (Cervus elaphus) on the Isle of Rum, Scotland, which is the subject of a long-term, individual-based study. We compared measures of performance including antler growth in young males and age at first reproduction in females and survival of deer with mothers still alive against those that have lost their mothers (orphans). We show that orphaning both before and after weaning increases the risk of a natural death for both sexes. For males, no maternal benefit was detectable past 24 months of age while, for females, post-weaning benefits continued throughout life. Orphaning resulted in compromised male physical condition as measured by a reduced probability of growing antlers by 16 months of age while no evidence for compromised reproduction was found in females. These results support assertions that post-weaning maternal associations affect the development and survival of offspring.     

The demographic consequences of the cost of reproduction in ungulates

The cost of reproduction can generate covariation between demographic rates that can potentially influence demography and population dynamics in long-lived iteroparous species. However, there has been relatively little work linking the survival cost of reproduction and population dynamics. The apparent scarcity of information on this important link is potentially due to covariation between vital rates, which can substantially influence fluctuations in population size. In this paper we examine the opportunity for survival costs of reproduction to leave a dynamic signature using a simulation model based broadly on an ungulate life history. We find that an increase in the cost delays the onset of reproduction and reduces reproductive rates of young, but not of prime-age, females. Accordingly, the number of offspring produced declines and the interval between reproductive events increases among young females experiencing high cost. These effects are translated to an age structure skewed toward young ages and reduced population density. These results suggest that, by delaying reproduction when conditions deteriorate, females protect their survival during the critical first three years of life, after which the negative effect of reproduction on survival declines. Unless conditions for reproduction are severe, it is not profitable to delay reproduction beyond age 3 years due to the high risk of death before having a chance to reproduce. We also demonstrate that lack of adjustment of reproductive strategies to elevated levels of the cost of reproduction, for example due to rapid changes in environmental conditions, results in lower average density and longevity compared to females that have sufficient time to adjust to changes in the cost. This suggests that even moderate costs of reproduction may have a major negative effect on population dynamics of ungulates.     

Sorption of iron-cyanide complexes on goethite in the presence of sulfate and desorption with phosphate and chloride

Soils are contaminated with potentially toxic iron-cyanide complexes by some industrial activities. The influence of sulfate on the sorption of the iron-cyanide complexes ferricyanide, [Fe(CN)6]3-, and ferrocyanide, [Fe(CN)6]4-, on goethite was investigated in batch experiments. The experiments were conducted as influenced by pH and varying sulfate/iron-cyanide complex concentration ratios. Furthermore, the desorption of iron-cyanide complexes sorbed on goethite was studied using phosphate and chloride solutions as influenced by pH and anion concentration. Over the whole pH range (pH 3.5 to 8), ferricyanide and sulfate showed similar affinities for the goethite surface. The extent of ferricyanide sorption strongly depended on sulfate concentrations and vice versa. In contrast, ferrocyanide sorption was only decreased (approximately 12%) by sulfate additions at pH 3.5. Ferricyanide was completely desorbed by 1 M chloride, ferrocyanide not at all. Unbuffered phosphate solutions (pH 8.3) desorbed both iron-cyanide complexes completely. Even in 70-fold excess, pH-adjusted phosphate solutions could not desorb ferrocyanide completely at pH 3.5. For ferricyanide we propose a sorption mechanism that is similar to the sulfate sorption mechanism, including outer-sphere and weak inner-sphere surface complexes on goethite. Ferrocyanide appears to form inner-sphere surface complexes. Additionally, we assume that ferrocyanide precipitates probably as a Berlin Blue-like phase at pH 3.5. Hence, ferrocyanide should be less mobile in the soil environment than ferricyanide or sulfate.     

A technical and economic comparison of biofiltration and wet chemical oxidation (scrubbing) for odor control at wastewater treatment plants

An economic and technical comparison of two odor control systems, a biofilter and a chemical wet scrubber, was conducted over a 1-year time period at a large municipal wastewater treatment plant. The biofilter system was designed to remove hydrogen sulfide gas and other oxidizable sewage odors from four covered gravity sludge thickeners, a gravity sludge thickener effluent channel and an influent splitter box for the gravity sludge thickeners. The sodium hypochlorite/sodium hydroxide wet scrubber was designed to control hydrogen sulfide gas and other oxidizable sewage odors from the covered primary settling tanks, influent distribution channels and effluent channel, and the mixing tank effluent channel. The technical comparison comprised their overall removal rates and efficiencies based on inlet H₂S concentrations and other operating variables. The economic comparison was designed to provide the cost per cubic meter of H₂S removed for each system. Influent and effluent gas samples were collected on a weekly basis. H₂S concentration levels were determined through the use of gas chromatography with a flame photometric detector. The results showed that the H₂S inlet gas concentration has a seasonal change with a maximum value occurring in August and September. The effluent H₂S concentration was lower than 2 ppm_v for both systems for most of the samples. The efficiency for both the biofilter and wet scrubber was above 95%, and was related to the operating and ambient conditions. The economic comparison revealed that the actual unit cost for the biofilter was higher than for the wet scrubber (U.S.160 /m < SUP > 3 < /SUP > H < SUB > 2 < /SUB > S removed versus U.S.160 /m³ H₂S removed versus U.S.131 /m³ H₂S removed). For both the biofilter and the wet scrubber, the investment costs are affected by the size/scale of the system, the design flow and other factors. For these systems, the mulch change costs, chemical usage costs, maintenance costs and power usage costs were mainly dependent on the actual odor gas loadings which showed substantial seasonal fluctuations as a function of the seasonal temperature. The worst case conditions reported here indicate that the H₂S concentrations generated during the summer months should be used to determine the design load.     

Non‐statutory sites of importance for nature conservation in the West Midlands

Many counties in England have systems of non‐statutory sites of importance for nature conservation in addition to the statutory National Nature Reserves, Sites of Special Scientific Interest and Local Nature Reserves. The paper describes the evolution of such a system over the past 20 years in the metropolitan county of the West Midlands. The system has been recognized by the local planning authorities who have included appropriate policies for the conservation of these sites in statutory development plans. The authority of such a system derives from the use of published criteria for the selection of sites, consensus over the application of these criteria, and consultation with the owners and occupiers of the sites.     

Sustainable procurement in practice: Lessons from local government

By committing to green procurement, the UK government has taken a key initial step towards sustainable development. But can this be put into practice? This policy analysis explores the background to green procurement in English local government through desk research and data collection, including interviews with five local authorities. It finds that green procurement has been encouraged through legislation, providing information and dismantling barriers, but momentum was lost following the Gershon review. Implementation of the new action plan would ensure green procurement becomes embedded within government procurement. New information to link up green procurement with organisational goals would also expand the horizons of green procurement.     

Incentives to diffuse advanced abatement technology under environmental liability law

Polluting firms with advanced abatement technology at their disposal have incentives or disincentives to share this technology with other polluting firms. The ‘direction’ and extent of those incentives depends on the liability rule applicable and the way technical change impacts marginal abatement costs. We establish that incentives for diffusion are socially optimal under strict liability and socially suboptimal under negligence if technical change lowers marginal abatement costs for all levels of abatement. Negligence may, however, induce better diffusion incentives than strict liability if technical change decreases (increases) marginal abatement costs for low (high) levels of abatement.