The importance of experience in the interpretation of conspecific chemical signals

Foraging bumblebees scent mark flowers with hydrocarbon secretions. Several studies have found these scent marks act as a repellent to bee foragers. This was thought to minimize the risk of visiting recently depleted flowers. Some studies, however, have found a reverse, attractive effect of scent marks left on flowers. Do bees mark flowers with different scents, or could the same scent be interpreted differently depending on the bees’ previous experience with reward levels in flowers? We use a simple experimental design to investigate if the scent marks can become attractive when bees forage on artificial flowers that remain rewarding upon the bees’ return after having depleted them. We contrast this with bees trained in the more natural scenario where revisits to recently emptied flowers are unrewarding. The bees’ association between scent mark and reward value was tested with flowers scent marked from the same source. We find that the bees’ experience with the level of reward determines how the scent mark is interpreted: the same scent can act as both an attractant and a repellent. How experience and learning influence the interpretation of the meaning of chemical signals deposited by animals for communication has rarely been investigated.     

The fate of sulfate in acidified pig slurry during storage and following application to cropped soil

Acidification of slurry with sulfuric acid is a recent agricultural practice that may serve a double purpose: reducing ammonia emission and ensuring crop sulfur sufficiency. We investigated S transformations in untreated and acidified pig slurry stored for up to 11 mo at 2, 10, or 20 degrees C. Furthermore, the fertilizer efficiency of sulfuric acid in acidified slurry was investigated in a pot experiment with spring barley. The sulfate content from acidification with sulfuric acid was relatively stable and even after 11 mo of storage the majority was in the plant-available sulfate form. Microbial sulfate reduction during storage of acidified pig slurry was limited, presumably due to initial pH effects and a limitation in the availability of easily degradable organic matter. Sulfide accumulation was observed during storage but the sulfide levels in acidified slurry did not exceed those of the untreated slurry for several months after addition. The S fertilizer value of the acidified slurry was considerable as a result of the stable sulfate pool during storage. The high content of inorganic S in the acidified slurry may potentially lead to development of odorous volatile sulfur-containing compounds and investigations are needed into the relationship between odor development and the C and S composition of the slurry.     

Objectively best or most acceptable? Expert and lay knowledge in Swedish wind power permit processes

This article analyses legal aspects of the Swedish wind power development, theoretically based on how different types of knowledge are represented in legal contexts, mainly in the courts. A sample of appealed wind power permits is analysed, a handful of relevant informants are interviewed – including two judges in the Land and Environment Court and the appeal court – and the legal setting is analysed. Of key interest here is the interplay between expert and lay statements in the court cases, which here is related to the concepts of calculating and communicative rationalities that are developed in the planning literature. The results indicate that the juridification – which takes place as a permit issue is appealed in the judiciary system – supports the calculating rationality more than the communicative, and that the plaintiffs often attempt to adapt in how they shape their argumentation.     

Experiences with unexpected structural chromosome aberrations in prenatal diagnosis in a danish series

The investigation of 5547 prenatal diagnoses showed 31 unexpected structural chromosome rearrangements. These included 3 Robertsonian translocations, 14 reciprocal translocations and 14 inversions. A11 were balanced, including 5 de novo rearrangements. In 3 of these cases an induced abortion was performed and in 2 cases children without detectable malformations were delivered.     

What have we learnt from the European Union's Emissions Trading System?

The EU Emissions Trading System (ETS) demonstrated the ability to design and launch a large-scale trading system in a short period of time. The path from initial reticence about emissions trading to implementation of the world's largest program is an important history. Three issues play a large role in the evaluation of the program to date and its on-going development: allocation plans, cost uncertainty, and leakage of emissions to abroad. Decisions in Phase I and II (2005-2012) were responsive to questions of political feasibility and implementation, but some of these decisions including allocation in particular will be substantially revised in Phase III (2013-2020).     

Socio-economic research in support of climate policy development: Mistra's Research Program Clipore

Mistra's Climate Policy Research Program, Clipore, is one of the largest research programs directed to support international climate policy development, involving research groups in Sweden, Norway, United States and India. It has been running from 2004 to 2011 with a budget of more than 100 MSEK (15?M USD). The paper briefly describes the program and its outcomes in relation to climate policy development. Discussion focuses on how the program has been able to be in the front of and include the development of emissions trading systems in Europe and the United States and how the program has been able to follow and produce inputs to the agenda of the United Nations Framework Convention on Climate Change (UNFCCC). The paper also discusses how the program has managed to present its outcomes and maintain an active dialogue with the various stakeholders. The paper emphasises options and obstacles in the communication between science and policy.     

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ¹⁵N and δ¹³C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000 ± 8600 ng g⁻¹ lw in liver of California sea lion, 14000 ± 5600 ng g⁻¹ lw in liver of harbor porpoise, 138000 ± 55000 ng g⁻¹ lw in liver of sea otters, 15700 ± 3600 ng g⁻¹ lw in liver of seabirds, 36100 ± 6100 ng g⁻¹ lw in arrow goby fish, 62800 ± 28400 ng g⁻¹ lw in oysters, and 12700 ± 1300 ng g⁻¹ lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100 ± 3800 ng g⁻¹ lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000 ± 900 ng g⁻¹ lw, mussel: 6100 ± 700 ng g⁻¹ lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42 ± 0.16 μg L⁻¹) and sediment (53 ± 14 ng g⁻¹ dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna.     

Polychlorinated biphenyls (PCBs) in indoor air originating from sealants in contaminated and uncontaminated apartments within the same housing estate

Twenty-four congeners of polychlorinated biphenyls (PCBs) were measured in 83 air samples and 20 elastic sealants samples of apartments with PCB-containing sealants. In addition, PCBs were measured in 21 air samples from reference apartments located in an uncontaminated section of the same estate. The PCB_tot levels in the air of the contaminated section were 168-3843 ng m⁻³ (mean: 1030 ng m⁻³), while the mean levels in the reference apartments were 6.03 ng m⁻³. The sum of the 24 measured PCB congeners in sealants from the contaminated section was 187-221 680 mg kg⁻¹. Principal component analysis revealed four groups among the sealant samples with different congener compositions, only two of which were clearly similar to known PCB mixtures, while two were not. Significant correlations and intercorrelations were observed between the lower chlorinated congeners in air and sealant, e.g. for PCB 28_air and 28_seal (p = 0.04) and for PCB 28_air and 52_air, 52_seal. However, no correlation was observed between the lower chlorinated congeners and the sums of PCB (∑PCB₆ or ∑PCB₂₄) or the higher chlorinated congeners. Analysis of air concentrations in relation to questionnaire data indicated that the indoor air levels could be reduced by increased cleaning and airing frequencies.     

Modeling riverine nutrient transport to the Baltic Sea: a large-scale approach

We developed for the first time a catchment model simulating simultaneously the nutrient land-sea fluxes from all 105 major watersheds within the Baltic Sea drainage area. A consistent modeling approach to all these major watersheds, i.e., a consistent handling of water fluxes (hydrological simulations) and loading functions (emission data), will facilitate a comparison of riverine nutrient transport between Baltic Sea subbasins that differ substantially. Hot spots of riverine emissions, such as from the rivers Vistula, Oder, and Daugava or from the Danish coast, can be easily demonstrated and the comparison between these hot spots, and the relatively unperturbed rivers in the northern catchments show decisionmakers where remedial actions are most effective to improve the environmental state of the Baltic Sea, and, secondly, what percentage reduction of riverine nutrient loads is possible. The relative difference between measured and simulated fluxes during the validation period was generally small. The cumulative deviation (i.e., relative bias) [Sigma(Simulated - Measured)/Sigma Measured x 100 (%)] from monitored water and nutrient fluxes amounted to +8.2% for runoff, to -2.4% for dissolved inorganic nitrogen, to +5.1% for total nitrogen, to +13% for dissolved inorganic phosphorus and to +19% for total phosphorus. Moreover, the model suggests that point sources for total phosphorus compiled by existing pollution load compilations are underestimated because of inconsistencies in calculating effluent loads from municipalities.     

A New Phosphorus Paradigm for the Baltic Proper

The external phosphorus (P) loading has been halved, but the P content in the water column and the area of anoxic bottoms in Baltic proper has increased during the last 30 years. This can be explained by a temporary internal source of dissolved inorganic phosphorus (DIP) that is turned on when the water above the bottom sediment becomes anoxic. A load-response model, explaining the evolution from 1980 to 2005, suggests that the average specific DIP flux from anoxic bottoms in the Baltic proper is about 2.3 g P m⁻² year⁻¹. This is commensurable with fluxes estimated in situ from anoxic bottoms in the open Baltic proper and from hydrographic data in the deep part of Bornholm Basin. Oxygenation of anoxic bottoms, natural or manmade, may quickly turn off the internal P source from anoxic bottoms. This new P-paradigm should have far-reaching implications for abatement of eutrophication in the Baltic proper.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-013-0441-3) contains supplementary material, which is available to authorized users.