Production and transmission of honey bee queen (Apis mellifera L.) mandibular gland pheromone

Summary The social cohesiveness of eusocial insect colonies is maintained primarily through the utilization of pheromones. In this study we quantitatively elucidated the production, secretion, and transmission of 9-keto2(E)-decenoic acid (9-ODA), one of the components of the mandibular gland pheromone of the honey bee queen Apis mellifera; this is the only identified primer pheromone complex in the eusocial insects. Mated queens produce 12–400 g of 9-ODA/day, or between 10% and 170% the average amount found in the glands at any one time. Approximately 0.5 g of 9-ODA is maintained on the body surface of queens by an equilibrium between exudation, internalization, tracking on the comb, and removal by workers. Retinue bees, attending the queen, remove the greatest amount, although the role of the wax as both a sink and a medium for pheromone transfer has been previously underestimated. Only about 1 in 10 retinue workers pick up substantial quantities of pheromone while attending the queen and, within seconds, most of the acquired 9-ODA is found externally on the abdomen, or in the gut. These attendants, also called messenger bees, transfer 9-ODA to other workers, mostly through direct contacts, but also via the wax. A model evaluating the pathways and relative quantities of 9-ODA transferred throughout the nest is presented. As well as being important for a basic understanding of the system, the results have implications for the proper design and use of pheromones in bee management.Offprint requests to: K. Naumann     

Simultaneous nitrification-denitrification and clarification in a pseudoliquified activated sludge system.

This paper describes results from a pilot study of a novel wastewater treatment technology, which incorporates nutrient removal and solids separation to a single step. The pseudoliquified activated sludge process pilot system was tested on grit removal effluent at flowrates of 29.4 to 54.7 m3/d, three different solid residence times (SRT) (15, 37, and 57 days), and over a temperature range of 12 to 28 degrees C. Despite wide fluctuations in the influent characteristics, the system performed reliably and consistently with respect to organics and total suspended solids (TSS) removals, achieving biochemical oxygen demand (BOD) and TSS reductions of > 96% and approximately 90%, respectively, with BOD5 and TSS concentrations as low as 3 mg/L. Although the system achieved average effluent ammonia concentrations of 2.7 to 3.2 mg/L, nitrification efficiency appeared to be hampered at low temperatures (< 15 degrees C). The system achieved tertiary effluent quality with denitrification efficiencies of 90 and 91% total nitrogen removal efficiency at a total hydraulic retention time of 4.8 hours and an SRT of 12 to 17 days. With ferric chloride addition, effluent phosphorous concentrations of 0.5 to 0.8 mg/L were achieved. Furthermore, because of operation at high biomass concentrations and relatively long biological SRTs, sludge yields were over 50% below typical values for activated sludge plants. The process was modeled using activated sludge model No. 2, as a two-stage system comprised an aerobic activated sludge system followed by an anoxic system. Model predictions for soluble BOD, ammonia, nitrates, and orthophosphates agreed well with experimental data.     

Detection of indoor PCB contamination by thermal desorption of dust. A rapid screening method?

Although PCB in caulking materials has been forbidden for many years in most of Europe, including Denmark, there has been continued interest to measure PCB levels in the air of contaminated buildings and blood of the occupants (Mengon and Schlatter 1993, Fromme et al. 1996, Ewers et al. 1998, Currado and Harrad 1998, Gabrio et al. 2000). The relatively low priority for investigations of this contamination is probably due to the small quantities inhaled compared to exposure via food, and the rapid metabolism of the most volatile congeners demonstrated by low concentrations of all congeners in the blood of exposed persons (Ewers et al. 1998, Gabrio et al. 2000). There is, however, evidence that PCB containing caulking materials have been used even during the '90s (Fromme et al. 1996). In Denmark, it is estimated that 75 t PCB is still in buildings (Organization of Sealant Branch's Manufacturers and Distributors 2000). During an investigation of dust from buildings with excessive microbial growth (including 35 rooms from 9 buildings), the analysis of semivolatile compounds by thermal desorption-GC/MS of samples from a single building surprisingly revealed large amounts of PCBs containing 3, 4 and 5 chlorine atoms, 10-20 times the amounts found in samples from other buildings. Extraction of the dust by SFE followed by GC/ECD analysis for 12 PCB congeners showed that there was approximately 20 times the total PCB concentrations in dust from the polluted building compared to the levels in the other buildings. Subsequent headspace analysis of caulking material from the polluted building revealed this to be the source. Shelf dust functions as a passive sampling medium and, thus, can be used as a screening method to detect PCB and other semivolatile pollution indoors.     

Homogeneous degradation of 1,2,9,10-tetrachlorodecane in aqueous solutions using hydrogen peroxide, iron and UV light

The homogeneous degradation of the polychlorinated n-alkane, 1,2,9,10-tetrachlorodecane (T4C10), was studied in aqueous solutions of hydrogen peroxide, including Fenton and photo-Fenton reaction conditions. All solutions were adjusted to a pH of 2.8 and an ionic strength of 0.1 M NaClO4 prior to photolysis. T4C10 (2 x 10(-6) M) was substantially degraded by the H2O2/UV system (1.0 x 10(-2) M H2O2), with 60% disappearance in 20 min of irradiation in a photoreactor equipped with 300 nm lamps of light intensity 3.6 x 10(-5) Ein L(-1) min(-1) (established by ferrioxalate actinometry). The reaction produced stoichiometric amounts of chloride ion indicating complete dechlorination of the chlorinated n-alkane. T4C10 degraded very slowly under Fenton (Fe2+/H2O2/dark) and Fenton-like (Fe3+/H2O2/dark) conditions. However, when the same solutions were irradiated, T4C10 degraded more rapidly than in the H2O2/UV system, with 61% disappearance in 10 min of exposure. The rapid degradation is related to the enhanced degradation of hydrogen peroxide to oxidizing *OH radicals under photo-Fenton conditions. Degradation was inhibited in both the H2O2/UV and photo-Fenton systems by the addition of KI and tert-butyl alcohol due to *OH scavenging.     

Detection of ciliostatic activity in fungal growth on building materials

Varying ciliostatic activity was found in extracts of biomass from building materials inoculated with pure isolates of some molds previously isolated from buildings. Extracts from growth on materials composed of finely divided cellulose (plaster board and construction cardboard) were more active than those from growth on Rockwool. Extracts of biomass from all three materials demonstrated an activity greater than control samples. Based on the activity observed here, it is conceivable that the measurement of ciliostatic activity of biomass scraped from contaminated building materials could be useful for planning removal strategies.     

Non-breeding habitat preference affects ecological speciation in migratory waders

Models of ecological speciation predict that certain types of habitat should be more conducive to species diversification than others. In this study, I test this hypothesis in waders of the sub-order Charadrii using the number of morphological sub-species per species as an index of diversity. I classified all members of this clade as spending the non-breeding season either coastally or inland and argue that these represent fundamentally different environments. Coastal mudflats are characterised by high predictability and patchy worldwide distribution, whilst inland wetlands are widespread but unpredictable. The results show that migratory species that winter coastally are sub-divided into more sub-species than those that winter inland. This was not the case for non-migratory species. I argue that coastal environments select for more rigid migratory pathways, whilst inland wetlands favour more flexible movement patterns. Population sub-division could then result from the passive segregation of breeding sites or from the active selection for assortative mating of ecomorphs.     

The influence of science on Canada's foreign policy on persistent organic pollutants (1985–2001)

The role of science in environmental foreign policymaking has received little attention in the international environmental politics literature, and systematic, in-depth case studies of the influence of science on environmental foreign policy with respect to persistent organic pollutants (POPs) are entirely missing. We present a case study of the influence of science on Canada's foreign policy on POPs from the discovery of the transboundary nature of the POPs problem around 1985 to the signing of the United Nations Stockholm Convention on Persistent Organic Pollutants in 2001. Influence was analyzed in terms of a knowledge–action methodology that focused on the types of scientific knowledge and the actions taken by scientists that were influential. Data were collected through interviews and extensive document analysis. We conclude that, while individual knowledge types and actions were influential during various periods (single-factor explanations), it was an increasingly layered and integrated “package” of knowledge types and actions, with human health impacts as its touchstone and partnering between scientists and non-scientists as its watchword, that propelled and sustained Canada's foreign policy on the POPs issue.     

A sustainability assessment framework for regional-scale Integrated Coastal Zone Management (ICZM) incorporating Inclusive Wealth,Satoumi, and ecosystem services science

Sustainability has become an increasingly important concept in the last few decades; however, its operational usefulness has not always been clear. In other words, some sustainability assessments may not provide decision makers with the practical information necessary to perform the assessment. This study proposes a novel operational sustainable assessment framework for Integrated Coastal Zone Management (ICZM) on a regional-scale based on a feasibility study in the Seto Inland Sea in Japan. The framework draws upon three separately developed concepts: Inclusive Wealth as the technical framework for the sustainability indicators; Satoumi (a traditional Japanese multifaceted coastal zone concept); and ecosystem services science. These three concepts complement each other when seeking to corroborate an assessment framework. Indicators based on the framework and relevant to the case study site were identified. Although Satoumi is a traditional Japanese knowledge, it is believed that its application may be instructive for other areas, as similar concepts can be found and utilized for the conduct of ICZM sustainability assessments.     

Climate change adaptation and mitigation in smallholder crop–livestock systems in sub-Saharan Africa: a call for integrated impact assessments

African mixed crop–livestock systems are vulnerable to climate change and need to adapt in order to improve productivity and sustain people’s livelihoods. These smallholder systems are characterized by high greenhouse gas emission rates, but could play a role in their mitigation. Although the impact of climate change is projected to be large, many uncertainties persist, in particular with respect to impacts on livestock and grazing components, whole-farm dynamics and heterogeneous farm populations. We summarize the current understanding on impacts and vulnerability and highlight key knowledge gaps for the separate system components and the mixed farming systems as a whole. Numerous adaptation and mitigation options exist for crop–livestock systems. We provide an overview by distinguishing risk management, diversification and sustainable intensification strategies, and by focusing on the contribution to the three pillars of climate-smart agriculture. Despite the potential solutions, smallholders face major constraints at various scales, including small farm sizes, the lack of response to the proposed measures and the multi-functionality of the livestock herd. Major institutional barriers include poor access to markets and relevant knowledge, land tenure insecurity and the common property status of most grazing resources. These limit the adoption potential and hence the potential impact on resilience and mitigation. In order to effectively inform decision-making, we therefore call for integrated, system-oriented impact assessments and a realistic consideration of the adoption constraints in smallholder systems. Building on agricultural system model development, integrated impact assessments and scenario analyses can inform the co-design and implementation of adaptation and mitigation strategies.F