Fertile diploid males in the ant Cataglyphis cursor: a potential cost of thelytoky?

Under the hymenopteran single-locus complementary sex-determination system, production of diploid males results from homozygosity at the sex-determiner locus. This arises when both parents transmit identical alleles at the locus to the offspring. In species reproducing asexually through thelytokous parthenogenesis, production of diploid males may also occur when the sex locus undergoes recombination and becomes homozygous in the offspring. Diploid males represent a substantial genetic load in hymenopteran populations because they often produce unviable sperm or sire sterile triploid female offspring. In the Mediterranean ant Cataglyphis cursor, the queen and workers can produce female offspring through automictic thelytokous parthenogenesis with central fusion, a mode of parthenogenesis that increases homozygosity. We report, for the first time, the presence of about 39 % of colonies producing adult diploid males (seven colonies out of 18). Overall, 8 % of adult males were diploid (12 diploid males out of the 146 males genotyped). Genotyping workers from the seven colonies producing diploid males showed that three diploid males were sons of queens and produced by thelytoky, six were probably sons of workers also produced by thelytoky and three were non-natal. Furthermore, the mating of a diploid male with two virgin queens in the laboratory led to the production of sterile triploid workers, which shows that diploid males in C. cursor are fertile, mate successfully and produce viable and functional but probably sterile female offspring. Because diploid males originate from thelytokous reproduction, they are only produced during sexual production and hence do not impair colony growth, which could explain why they are not removed at early brood stages.     

Reproductive periodicity of the scleractinian coral Lophelia pertusa from the Trondheim Fjord, Norway

Between 2002 and 2008, samples of the cold-water scleractinian coral Lophelia pertusa were collected from the Trondheim Fjord in Norway to examine reproductive periodicity. Collections were made from three locations: Tautra, (63°35.36′N, 10°31.23′E at 40–70 m), Stokkbergneset (63°28.18′N, 09°54.73′E at 110–500 m), and Røberg (63°28.88′N, 09°59.50′E at 250 m). Populations of L. pertusa from the Trondheim Fjord initiated oogenesis in January and spawning occurred from late January to early March the following year. Gametogenic cycles of the female L. pertusa samples overlapped by approximately 2 months, with oogonia visible in January, but this was not evident in the males. This paper provides the most complete gametogenic cycle to date and spawning observations for this important structure-forming species. The results from fjord populations are compared with published and preliminary data from other regions and are discussed in the context of regional differences in physical and biological variables, particularly food supply. Differences in gametogenic cycles within a single species provide a rare opportunity (especially in deep-sea species) to examine potential drivers of reproduction.     

A guide to qualitative attribution methods for evaluation in conservation

Knowledge of what conservation interventions improve biodiversity outcomes, and in which circumstances, is imperative. Experimental and quasi-experimental methods are increasingly used to establish causal inference and build the evidence base on the effectiveness of interventions, but their ability to provide insight into how and under what conditions an intervention should be implemented to improve biodiversity outcomes faces limitations. A suite of attribution methods that leverage qualitative methods for causal inference is available but underutilized in conversation impact evaluation. This article provides a guide to 5 such qualitative attribution methods: contribution analysis, process tracing, realist evaluation, qualitative comparative analysis, and most significant change. It defines and introduces each method and then illustrates how they could be applied through a case study of community conservancies in Namibia. This guide provides examples of how qualitative attribution methods can advance knowledge of what works, in which contexts, and why in biodiversity conservation.     

How unnecessarily high abatement costs and unresolved distributional issues undermine nutrient reductions to the Baltic Sea

This paper systematically reviews the literature on how to reduce nutrient emissions to the Baltic Sea cost-effectively and considerations for allocating these costs fairly among countries. The literature shows conclusively that the reduction targets of the Baltic Sea Action Plan (BSAP) could be achieved at considerably lower cost, if countries would cooperate to implement the least costly abatement plan. Focusing on phosphorus abatement could be prudent as the often recommended measures—wastewater treatment and wetlands—abate nitrogen too. An implication of our review is that the potential for restoring the Baltic Sea to good health is undermined by an abatement strategy that is more costly than necessary and likely to be perceived as unfair by several countries. Neither the BSAP nor the cost-effective solution meet the surveyed criteria for fairness, implying a need for side-payments.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01580-4.     

Sorption of thallium(I) onto geological materials: influence of pH and humic matter

The sorption behaviour of the severely toxic heavy metal thallium (Tl) as a monovalent cation onto three representative materials (goethite, pyrolusite and a natural sediment sampled from a field site) was examined as a function of pH in the absence and presence of two natural humic acids (HAs), using ²⁰⁴Tl(I) as a radiotracer. In order to obtain a basic understanding of trends in the pH dependence of Tl(I) sorption with and without HA, sorption of HAs and humate complexation of Tl(I) as a function of pH were investigated as well. In spite of the low complexation between Tl(I) and HAs, the presence of HAs results in obvious alterations of Tl(I) sorption onto pyrolusite and sediment. An influence on Tl(I) sorption onto goethite was not observed. Predictions of K_d (distribution coefficient) for Tl(I) on goethite in the presence of HAs, based on a linear additive model, agree well with the experimental data, while a notable disagreement occurs for the pyrolusite and sediment systems. Accordingly, it is suggested that HAs and goethite may act as a non-interacting sorbent mixture under the given conditions, but more complex interactions may take place between the HAs and the mineral phases of pyrolusite or sediment.     

Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.     

Role of sea-ice biota in nutrient and organic material cycles in the northern Baltic Sea

This paper compiles biological and chemical sea-ice data from three areas of the Baltic Sea: the Bothnian Bay (Hailuoto, Finland), the Bothnian Sea (Norrby, Sweden), and the Gulf of Finland (Tv?rminne, Finland). The data consist mainly of field measurements and experiments conducted during the BIREME project from 2003 to 2006, supplemented with relevant published data. Our main focus was to analyze whether the biological activity in Baltic Sea sea-ice shows clear regional variability. Sea-ice in the Bothnian Bay has low chlorophyll a concentrations, and the bacterial turnover rates are low. However, we have sampled mainly land-fast level first-year sea-ice and apparently missed the most active biological system, which may reside in deformed ice (such as ice ridges). Our limited data set shows high concentrations of algae in keel blocks and keel block interstitial water under the consolidated layer of the pressure ridges in the northernmost part of the Baltic Sea. In land-fast level sea-ice in the Bothnian Sea and the Gulf of Finland, the lowermost layer appears to be the center of biological activity, though elevated biomasses can also be found occasionally in the top and interior parts of the ice. Ice algae are light limited during periods of snow cover, and phosphate is generally the limiting nutrient for ice bottom algae. Bacterial growth is evidently controlled by the production of labile dissolved organic matter by algae because low growth rates were recorded in the Bothnian Bay with high concentrations of allochthonous dissolved organic matter. Bacterial communities in the Bothnian Sea and the Gulf of Finland show high turnover rates, and activities comparable with those of open water communities during plankton blooms, which implies that sea-ice bacterial communities have high capacity to process matter during the winter period.     

Statistical matching for conservation science

The awareness of the need for robust impact evaluations in conservation is growing and statistical matching techniques are increasingly being used to assess the impacts of conservation interventions. Used appropriately matching approaches are powerful tools, but they also pose potential pitfalls. We outlined important considerations and best practice when using matching in conservation science. We identified 3 steps in a matching analysis. First, develop a clear theory of change to inform selection of treatment and controls and that accounts for real-world complexities and potential spillover effects. Second, select the appropriate covariates and matching approach. Third, assess the quality of the matching by carrying out a series of checks. The second and third steps can be repeated and should be finalized before outcomes are explored. Future conservation impact evaluations could be improved by increased planning of evaluations alongside the intervention, better integration of qualitative methods, considering spillover effects at larger spatial scales, and more publication of preanalysis plans. Implementing these improvements will require more serious engagement of conservation scientists, practitioners, and funders to mainstream robust impact evaluations into conservation. We hope this article will improve the quality of evaluations and help direct future research to continue to improve the approaches on offer.     

Uncertainty analysis in integrated assessment: the users’ perspective

Integrated Assessment (IA) models aim at providing information- and decision-support to complex problems. This paper argues that uncertainty analysis in IA models should be user-driven in order to strengthen science–policy interaction. We suggest an approach to uncertainty analysis that starts with investigating model users’ demands for uncertainty information. These demands are called “uncertainty information needs”. Identifying model users’ uncertainty information needs allows focusing the analysis on those uncertainties which users consider relevant and meaningful. As an illustrative example, we discuss the case of examining users’ uncertainty information needs in the SEAMLESS Integrated Framework (SEAMLESS-IF), an IA model chain for assessing and comparing alternative agricultural and environmental policy options. The most important user group of SEAMLESS-IF are policy experts at the European and national level. Uncertainty information needs of this user group were examined in an interactive process during the development of SEAMLESS-IF and by using a questionnaire. Results indicate that users’ information requirements differed from the uncertainty categories considered most relevant by model developers. In particular, policy experts called for addressing a broader set of uncertainty sources (e.g. model structure and technical model setup). The findings highlight that investigating users’ uncertainty information needs is an essential step towards creating confidence in an IA model and its outcomes. This alone, however, may not be sufficient for effectively implementing a user-oriented uncertainty analysis in such models. As the case study illustrates, it requires to include uncertainty analysis into user participation from the outset of the IA modelling process.     

Calf circumferences in fetuses and neonates with and without talipes equinovares. A prospective cohort study

Objective

Children and adults with talipes equinovarus (TEV) have smaller calves and shorter feet compared to non-affected controls. Do these changes have a prenatal onset?

Methods

A prospective cohort study (January 2020–July 2021) was conducted with serial ultrasonographic measurements at 20 and 28 weeks gestation and measurements directly and 6 weeks after birth. Calf circumference and width, foot length and length of humerus, ulna, radius, femur, tibia and fibula were measured in TEV and were compared to a control population. Calculated sample size necessitated a minimal population of 10 cases with TEV and 50 controls.

Results

Twenty cases with TEV and 62 controls were included. Fetal calf circumference (p < 0.001) and width (p < 0.001) were smaller in the TEV group in comparison to the control group, which persisted after birth. Growth in foot length (p < 0.001) and calf width (p 0.003) declined prenatally over time. The bone lengths and upper leg circumference were not smaller or shorter in TEV compared to controls.

Conclusion

This prospective cohort study demonstrated the prenatal onset of reduced calf and foot size in fetuses with TEV from 20 weeks and onwards, which persists directly after birth. To investigate whether reduction in circumference initiates TEV or is caused by TEV, further examination is needed.