A decision support system for wet soil cleaning

Newly developed software can predict the essential characteristics of the sand product resulting from the ex-situ washing of contaminated soil, dredging sludge or breaker sand. The system was designed for the Dutch situation and it works on the basis of readily available information. The primary output of the system is an assessment of the reusability of the sand product, which is obtained by comparing the prediction of the residual contamination and engineering quality with accepted levels and standards for building materials. The system also provides a ranking of potential applications for the sand with respect to treatment cost, the amount of recycled material or the environmental quality of the product. The software integrates soil cleaning expertise and unit process modelling in a way that allows varying levels of refinement of input data, ranging from a simple identification of the pollution source to a detailed particle size distribution of the contaminated soil. Tests on a database containing information on 117 processed batches of soil, dredging sludge and breaker sand show an 80% success rate in predicting cleanability, even though the input contamination levels were predominantly taken from (relatively inaccurate) in-situ data.     

Analysis of volatile organic compounds, using the purge and trap injector coupled to a gas chromatograph/ion-trap mass spectrometer: review of the results in Dutch surface water of the Rhine, Meuse, Northern Delta Area and Westerscheldt, over the period 1992-1997

Volatile organic compounds are widely introduced into the Dutch aquatic environment. Liquid-liquid extraction and isolation by means of resins give poor recoveries for volatiles. In this study, a method has been developed to analyse these compounds with a purge and trap injection (PTI) coupled to a chromatograph/ion trap mass spectrometer. Volatile compounds are "purged" from the sample by carrier gas flow and transported through a condenser to a cooled trap. The bulk of liquid matrix is condensed in the condenser, while volatile compounds are left unaffected. The compounds of interest are trapped at a low temperature, by liquid nitrogen in the cooled trap of fused silica. Injection takes place by flash heating of the trap. The detection limits of the volatile compounds are in the range of 0.001-0.04 microgram l-1, in full spectrum mode. In this paper a review of the results in Dutch surface water of the Rhine, Meuse, Northern Delta Area and Westerscheldt, over the period 1992-1997, is presented. For calamities causing high levels of volatiles, the method is very useful. The compounds can be monitored over a certain period. In the Meuse, high levels of volatile organic compounds are observed. Diisopropyl ether at a maximum of 592 micrograms l-1.     

Sperm limitation and the evolution of extreme polyandry in honeybees (Apis mellifera L.)

Honeybee queens (Apis mellifera) show extreme levels of polyandry, but the evolutionary mechanisms underlying this behaviour are still unclear. The sperm-limitation hypothesis, which assumes that high levels of polyandry are essential to get a lifetime sperm supply for large and long-lived colonies, has been widely disregarded for honeybees because the semen of a single male is, in principle, sufficient to fill the spermatheca of a queen. However, the inefficient post-mating sperm transfer from the queens lateral oviducts into the spermatheca requires multiple matings to ensure an adequate spermatheca filling. Males of the African honeybee subspecies A. m. capensis have fewer sperm than males of the European subspecies A. m. carnica. Thus, given that sperm limitation is a cause for the evolution of multiple mating in A. mellifera, we would expect A. m. capensis queens to have higher mating frequencies than A. m. carnica. Here we show that A. m. capensis queens indeed exhibit significantly higher mating frequencies than queens of A. m. carnica, both in their native ranges and in an experiment on a North Sea island under the same environmental conditions. We conclude that honeybee queens try to achieve a minimum number of matings on their mating flights to ensure a sufficient lifetime sperm supply. It thus seems premature to reject the sperm-limitation hypothesis as a concept explaining the evolution of extreme polyandry in honeybees.Communicated by R.E. Page     

The Journal of Coastal Conservation, 1995–2004

This paper concludes the publication of theJournal of Coastal Conservation from 1995–2004 after the European Coastal Union and the Publishers decided to terminate the production of the journal. We look back at the 206 research papers published in this period while concentrating on Geographical and ecological variation, Focuses and trends, and Progress in European coastal conservation and management. Three indices are added: (1) a list of the 206 papers; (2) an Author Index; and (3) a Subject Index based on the titles, keywords and some additional important subjects found in the tables and figures.     

Why do Varroa mites invade worker brood cells of the honey bee despite lower reproductive success?

Varroa jacobsoni reproduces both in drone and worker brood cells of honey bees, but in drone cells reproductive success is higher than in worker cells. A simple model using clonal population growth as a fitness measure has been developed to study the circumstances under which specialization on drone brood would be a better strategy than reproduction in both types of cell. For European Apis mellifera, the model suggests that if mites have to wait less than 7 days on average before they can invade a drone cell, specialization on drone brood would be a better strategy. This is close to the estimated waiting time of 6 days. Hence, small differences in reproductive success in drone and worker cells and in the rate of mortality may determine whether specialization on drone brood will be promoted or not. In European A. mellifera colonies, Varroa mites invade both drone and worker cells, but specialization on drone brood cells seems to occur to some extent because drone cells are more frequently invaded than worker cells. In the parasite-host association of V. jacobsoni with African or Africanized A. mellifera or with A. cerana, the mites also invade both drone and worker cells, but the mites specialize on drone brood for reproduction since a large percentage of the mites in worker brood do not reproduce. Only in the parasite-host association of Euvarroa sinhai, a mite closely resembling V. jacobsoni, and A. forea is specialization complete, because these mites only invade drone brood.     

Biotechnological intervention for societal development (BioSangam 2020)

Environmental Science and Pollution Research -     

A synthesis of the arctic terrestrial and marine carbon cycles under pressure from a dwindling cryosphere

The current downturn of the arctic cryosphere, such as the strong loss of sea ice, melting of ice sheets and glaciers, and permafrost thaw, affects the marine and terrestrial carbon cycles in numerous interconnected ways. Nonetheless, processes in the ocean and on land have been too often considered in isolation while it has become increasingly clear that the two environments are strongly connected: Sea ice decline is one of the main causes of the rapid warming of the Arctic, and the flow of carbon from rivers into the Arctic Ocean affects marine processes and the air–sea exchange of CO₂. This review, therefore, provides an overview of the current state of knowledge of the arctic terrestrial and marine carbon cycle, connections in between, and how this complex system is affected by climate change and a declining cryosphere. Ultimately, better knowledge of biogeochemical processes combined with improved model representations of ocean–land interactions are essential to accurately predict the development of arctic ecosystems and associated climate feedbacks.     

Life cycle energy use,costs, and greenhouse gas emission of broiler farms in different production systems in Iran—a case study of Alborz province

In order to achieve sustainable development in agriculture, it is necessary to quantify and compare the energy, economic, and environmental aspects of products. This paper studied the energy, economic, and greenhouse gas (GHG) emission patterns in broiler chicken farms in the Alborz province of Iran. We studied the effect of the broiler farm size as different production systems on the energy, economic, and environmental indices. Energy use efficiency (EUE) and benefit-cost ratio (BCR) were 0.16 and 1.11, respectively. Diesel fuel and feed contributed the most in total energy inputs, while feed and chicks were the most important inputs in economic analysis. GHG emission calculations showed that production of 1000 birds produces 19.13 t CO_2-eq and feed had the highest share in total GHG emission. Total GHG emissions based on different functional units were 8.5 t CO_2-eq per t of carcass and 6.83 kg CO_2-eq per kg live weight. Results of farm size effect on EUE revealed that large farms had better energy management. For BCR, there was no significant difference between farms. Lower total GHG emissions were reported for large farms, caused by better management of inputs and fewer bird losses. Large farms with more investment had more efficient equipment, resulting in a decrease of the input consumption. In view of our study, it is recommended to support the small-scale broiler industry by providing subsidies to promote the use of high-efficiency equipment. To decrease the amount of energy usage and GHG emissions, replacing heaters (which use diesel fuel) with natural gas heaters can be considered. In addition to the above recommendations, the use of energy saving light bulbs may reduce broiler farm electricity consumption.     

Gender in integrated water management: an analysis of variation

Gender is an important variable in water use, policy, and intervention. This article explores this variation and its policy implications. Concepts are applied in several case studies to draw generic conclusions. Variation is related to the purpose of water use (consumptive or productive) and to the local, culture-specific patterns of the intra-household organization of consumption for family welfare (which includes domestic water provision) and income-generation (for which water is an input, especially in rural areas). For domestic water use, the intra-household sharing of unpaid domestic responsibilities is a key gender issue. Water for productive use, on the other hand, is embedded in the gendered organization of household economic activity, as elaborated for smallholder-irrigated agriculture. In female-managed and dual farming systems, where a high proportion of farm decision-makers are women, irrigation agencies need to better target their support. In male-managed farming systems, however, the majority of women lack their own farm enterprise in which water is an input. Women's access to land, markets and credits besides access to water, is at stake. To conclude, given the strong variation in water use along gender lines, gender analysis is indispensable for any concrete water policy and intervention.