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The increase in the temperature of surface waters has been studied for many decades, and various methods have been used to predict the most probable scenarios. The present study was undertaken to test the following research hypothesis: the warming of surface waters in winter (caused by the inflow of geothermal water) significantly modifies the dynamics, significance and type of relationships in zooplankton communities colonizing mine pit reservoirs. These relationships were examined with the use of network graph analysis for three thermal variants: warm winters (WW), moderate winters (MW), and cold winters (CW). The CW network was most cohesive, and it was controlled by eutrophic Rotifera (Trichocerca pusilla, Pompholyx sulcata, Keratella tecta) and Copepoda, with an equivalent number of positive and negative interspecific relationships. An increase in water temperature in winter led to a decrease in primary production, a decrease in the values of centrality attributes in MW and WW networks, and an increase in the significance of species that communicated with the highest number of species across sub-networks. Moderate winters increased the role of ecologically and functionally diverse species, which contributed to the heterogeneity of the MW network. The WW network was least cohesive, and it was controlled by small-sized psammophilous and phytophilous rotifers (Monommata maculata, Cephalodella spp.) and littoral cladocerans Alona spp. Adults Copepoda were not identified in the network, and the significance of antagonistic relationships decreased, which indicates that the WW network structure was weak and unstable. The results of the impact of warm winters and the flattening of the annual water temperature amplitude on the zooplankton network may be a projection of the expected global changes. These effects are particularly important in water reservoirs exposed to anthropogenic pressure and where changes in the thermal regime can influence future ecosystem services.

Zooplankton are an important link between trophic levels in aquatic ecosystems, and their response to organic carbon is likely to have broad implications for lake food webs. The main objective of t...

Lakes provide different ecosystem services, including those related to tourism and recreation. Sustainable development principles should be respected in lake tourism planning. The aim of this study was to assess the impact of tourism on the lakeshore zone in a typical post-glacial Lakeland in Northern Poland (Central Europe). An explanatory analysis of the distribution of individual spatial factor values was performed using the SHapley Additive exPlanations algorithm (SHAP). In a first step, the aim was to select a Machine Learning model for modelling based on Shapley values. The greater or lesser influence of a given factor on the tourism function was measured for individual lakes. The final results of ensemble modelling and SHAP were obtained by averaging the results of five random repetitions of the execution of these models. The impact of tourism on the lakeshore zone can be much more accurately determined using an indirect method, by analysing the tourism and recreational infrastructure constantly present there. The values of the indices proposed in the study provide indirect information on the number of tourists using the tourist and recreational facilities and are a measure of the impact of tourism on the lakeshore zone. The developed methodology can be applied to the majority of post-glacial lakes in Europe and other regions of the world in order to monitor the threats resulting from shore zone exploitation. Such studies can be an appropriate tool for management and planning by the relevant authorities.

The authors acknowledge COST Action ES 1105 "CYANOCOST Cyanobacterial blooms and toxins in water resources: Occurrence impacts and management" and COST Action Global Change Biology ES 1201 NETLAKE -Networking Lake Observatories in Europe" for contributing to this study through networking and knowledge sharing with European experts in the field. We acknowledge the members of the Global Lake Ecological Observatory Network (GLEON) for their collaborative spirit and enthusiasm that inspired the grassroots effort of the EMLS. E.M. was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation to Bas Ibelings and by supplementary funding from University of Geneva. We thank Wendy Beekman for the nutrient analysis. We thank Pieter Slot for assisting with the pigment analysis. We thank Dr. Ian Jones for valuable feedback on an earlier version of the manuscript. We thank the Leibniz Institute of Freshwater Ecology and the Aquatic Microbial Ecology Group for logistic and technical support of J. Fonvielle and H.-P. Grossart, and the Leibniz Association for financial support. H.P. was supported by the US National Science Foundation (1840715, 1831096). A.C.'s work was funded by the Spanish Agencia Estatal de Investigacion and EU funds through the project CLIMAWET (CGL2015-69557-R). The collection of data for Lough Erne and Lough Neagh were funded by the Department of Agriculture, Environment and Rural Affairs, Northern Ireland. We are grateful to Kristiina Vuorio from the Freshwater Centre of the Finnish Environment institute for her help in organizing, collecting and analysing samples by the University of Jyvaskyla and to Gerald Dorflinger from the Water Development Department of Cyprus for his assistance with the sampling in Cyprus and for granting the CUT team permission to use WDD's equipment. Finally, we would like to thank the numerous other assistants that helped realizing each local survey. Open access funding provided by Universite de Geneve., To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature., European Cooperation in Science and Technology (COST) ES 1105 ES 1201, Swiss State Secretariat for Education, Research and Innovation, University of Geneva, Leibniz Association, National Science Foundation (NSF) 1840715 1831096, Spanish Agencia Estatal de Investigacion, European Commission CGL2015-69557-R, Department of Agriculture, Environment and Rural Affairs, Northern Ireland

Our study aims to elucidate how decreases in peatland above-ground net primary production (AG-NPP) might be explained by a network of relationships between some nutritive elements and the N:P ratios in different plant groups. We focused on three functional groups of peatland plants with different growth form: Sphagnum mosses, shrubs, and non-woody vascular plants (NW-VP) in an ombrotrophic peatland in northeastern Poland affected by moderate N deposition. We measured AG-NPP and elemental stoichiometry (C, N, P, Ca, Fe) in different plant species belonging to these functional plant groups, and growing within different microhabitats: Sphagnum bog hummocks and hollows, and Sphagnum mat. The functional groups significantly differed only in AG-NPP, but not in nutrient contents within the study sites. Sphagnum mosses had the highest mean production (247.6 g/m2), while it was lower in NW-VP (71.7 g/m2) and shrubs (49.4 g/m2). The plant groups had a comparable N:P ratio. The N:P ratio was correlated with K, Ca, and Fe, but not with N in Sphagnum mosses. In NW-VP and shrubs, we observed an increased N:P ratio with increasing plant N content. However, increased N:P ratio was only negatively correlated with C content in Sphagnum mosses. Based on these data, we performed an analysis of elemental and production relations in peatland vegetation at the ecosystem level. Structural equation modelling (SEM) suggests that an increase of the N:P ratio in the vegetation, induced by higher N concentration, plus indirect effects of Fe, might explain a lower carbon concentration in plant production. As an outcome of this network of interactions, the AG-NPP of the entire peatland vegetation might be reduced.

This study aims to demonstrate that factors associated with climate dynamics, such as temperature and wind, affect the ecosystem of the shallow Vistula Lagoon in the southern Baltic and cause nutrient forms phytoplankton interactions: the growth of biomass and constraints of it. This occurs through a network of direct and indirect relationships between environmental and phytoplankton factors, including interactions of positive and negative feedback loops. Path analysis supported by structural equation modeling (SEM) was used to test hypotheses regarding the impact of climate factors on algal assemblages. Increased phytoplankton biomass was affected directly by water temperature and salinity, while the wind speed effect was indirect as it resulted in increased concentrations of suspended solids (SS) in the water column. Simultaneously, the concentration of SS in the water was positively correlated with particulate organic carbon (POC), particulate nitrogen (PN), and particulate phosphorus (PP), and was negatively correlated with the total nitrogen to phosphorus (N:P) ratio. Particulate forms of C, N, and phosphorus (P), concentrations of soluble reactive phosphorus (SRP) and nitrate and nitrite nitrogen (NO3-N + NO2-N), and ratios of the total N:P and DIN:SRP, all indirectly effected Cyanobacteria C concentrations. These processes influence other phytoplankton groups (Chlorophyta, Bacillariophyceae and the picophytoplankton fraction). Increased levels of SRP associated with organic matter (POC), which stemmed from reduced DIN:SRP ratios, contributed to increased Cyanoprokaryota and picophytoplankton C concentrations, which created a positive feedback loop. However, a simultaneous reduction in the total N:P ratio could have inhibited increases in the biomass of these assemblages by limiting N, which likely formed a negative feedback loop. The study indicates that the nutrients-phytoplankton feedback loop phenomenon can intensify eutrophication in a temperate lagoon, including increases of the biomass of Cyanobacteria and picophytoplankton. However, it can also constrain this increase.

The extent of changes at the ecosystem level due to external dynamics from year to year of meteorological conditions is one of the basic determinants of climate change. The object of the study is the sensitivity of a set of environmental and planktonic factors shaping the ecosystem of a temperate shallow lagoon (the Vistula Lagoon, South Baltic) to weather fluctuations from year to year. The specific question concerned the short-term advantage of the sequence of environmental changes related to the impact of wind or those caused by the air temperature. The average speed in the prevailing westerly winds in the first summer research season was 3.05 m/s, while in the second it was 3.84 m/s. Simultaneously, the air temperature changed on average from 16.8 to 17.3 °C. The accuracy of the division of the two-year data set of ecosystemic parameters into the first colder and less windy and the second, warmer and windier summer was analyzed. For this purpose, several machine learning models were used. Next, the model with the highest accuracy was selected for the explanatory modelling based on game theory metrics Shapley Value. The analysis based on the interactions among ecological factors shows that the dynamics of the climate on a year-to-year scale can bring significantly more environmental changes in the shallow lagoon by an increase in wind speed rather than by an increase in air temperature. More windy weather in the summer in the subsequent year caused higher wind action, suspended solids, silicates and diatoms concentration. Simultaneously, the same conditions resulted in lower concentrations of dissolved organic carbon and nitrogen forms in water, accompanied by a reduction of Cyanobacteria biomass. The procedure presented in the study can be used for environmental prognostics of the environmental effects of climate change.

In the article the rebuilding process of sport in polish education after the Second World War and the formation of a new model of school sports in the years 1945–1953 were presented. It was a special period of raising the country from the ravages of war. A new political system was introduced that had a significant impact on the development of education and a new organization of school sports. In the first years after the war the dynamic development of vocational education was particularly observed. New types of vocational schools were created. Many sport disciplines were promoted in schools. Additionally, new forms of sport competitions were introduced. In 1950 the Minister of Education published regulation that included school sports in the framework of education. The school sports groups organized in 1950 in all secondary schools, pedagogical high schools and higher organized primary schools gave students opportunity to do sport in additional time. The article is based on the existing literature and on the preserved archival sources and press materials.

Corporate social responsibility has been widely discussed and analyzed from the business perspective for several decades. The changes and challenges that universities have had to face during this time made them begin to undertake, with varying degrees of awareness, socially responsible actions. The aim of the paper is to present the issue of university social responsibility and attempt to evaluate whether the activities undertaken by the Faculty of Economics and Management at the University of Bialystok can be regarded as socially responsible ones. The analysis of the actions taken by this institution leads to the conclusion that despite the lack of a formally developed concept of social responsibility, the Faculty engages in a number of pro-social activities.

Using an input-output ecosystem model, it was demonstrated that wetlands of the various stages of anthropogenic transformations typical for the postglacial landscape of N-E Poland vary in nitrogen (N) and phosphorus (P) forms retention. It concerned particularly nitrates (NO3-N) and phosphates (PO4-P), the most responsible for eutrophication effect. The calculation of retention effectiveness for studied wetland ecosystems showed that undrained minerotrophic peatland and transition bog retained about 70–85% of total N, including 95% of nitrates, but at the same time, they lost more than 50% of incoming phosphates. Wetlands with a shallow lake or transition bog crossed by a watercourse were considered as typical through-flowing systems with at most a moderate tendency to retained phosphates. Drained peatlands were considered dangerous in exporting N and P forms into recipient lakes and rivers. A directly drained minerotrophic fen lost even 70% of nitrates in the first year after melioration. Formerly drained peatlands can also lose nitrates, but first of all, they lost even 80–100% of total phosphorus input. All drained peatlands examined did not retain or lose total nitrogen and phosphates.

The aim of the study was to create a procedure and test it in a case study that would permit forming a predicted depiction of the cause-and-effect network of connections in the lagoon ecosystem. We propose the novelty procedure as a tool for predicting transformations in the structure of links within ecosystems and forecasting changes in the impact some ecological factors have on others. An attempt was made to combine the Structural Equation Modeling (SEM) and Artificial Neural Network (ANN) tools to obtain the most reliable model of the dependency structure among variables that would be based on prediction data from the initial structural model and processed with a backpropagation algorithm. The subject of the explanatory-predictive analysis in this work was the Vistula Lagoon (southern Baltic) ecosystem network: physical-chemical factors – zooplankton – phytoplankton – organic carbon forms. The SEM-ANN-SEMpredict modeling sequence produced satisfactory adjustment rates of the ANN models for training and validation trials for the majority of the organic parameters analyzed. Higher matching rates and a higher number of relationships were obtained with the SEMpredict model than with the SEM model based on observed data. The role of physical factors changed in the predictive model compared to the explanatory model. Wind speed changed the direction of the impact on the picophytoplankton from a negative to one that facilitated growth and influenced on the cyanobacteria biomass increase. The role of salinity in promoting the growth of phytoplankton groups in relation to the impact of basin depth was more prominent. The analysis of both the new predictive network of direct links and the total effect of these relationships permitted us to extend our knowledge about potential phenomena that can occur in the ecosystem studied. Innovative methodology combined SEM and ANN network models to analyze the structure and prediction of ecosystem network indicated important potential properties of ecological systems.

The aim of the study was to investigate the biocenotic structure of relations among zooplankton and phytoplankton taxa using the innovative approach combining graph theory and structural equation modeling (SEM). The analysis focused on the biocenosis of the Vistula Lagoon (southern Baltic) that included 32 zooplankton species and eight phytoplankton associations. It was presented as a graph model in which negative interactions were designated that indicate feeding and predatory trophic relations and also competition among species and taxonomic groups. Based on the analysis of the graph attributes, the phytoplankton groups (picophytoplankton and diatoms), among which communication in the biocenosis proceeds mainly through the zooplankton species that feed on them, had the highest closeness centrality indicators. High values of this indicator were also noted for the Copepoda species Eurytemora affinis, because of its numerous relations with predation and competition. The relation between the Cladocera genus Ceriodaphnia sp. and the phytoplankton groups of Dinoflagellata and Cryptophytes, as measured with the edge betweenness indicator, had the greatest impact on biocenotic network cohesion, and this revealed the role of rare taxa in the biocenosis. Data from the SEM graph model that was obtained based on regression analysis indicated the domination of co-occurring taxa when the algal food base was abundant and the negative dependence of zooplankton species feeding on the main groups of phytoplankton. The dominating crustacean in the model was Calanoida nauplii, which initiated a few relational sequences in this trophic system. Among the Rotifera, the dominating species in this instance was Keratella c. cochlearis. The innovative complementary use of modeling based on graph theory and SEM to characterize the ecological systems appeared to be an effective tool with significant research and practical potential.

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains. © 2018 by the authors. Licensee MDPI, Basel, Switzerland., The authors acknowledge COST Action ES 1105 “CYANOCOST—Cyanobacterial blooms and toxins in water resources: Occurrence impacts and management” and COST Action ES 1201 “NETLAKE—Networking Lake Observatories in Europe” for contributing to this study through networking and knowledge sharing with European experts in the field. Evanthia Mantzouki was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation (SERI) to Bas Ibelings and by supplementary funding from the University of Geneva. We thank Clare Ahnlund, Ena Suarez and Irene Gallego for helping out with the Swiss survey. We thank Wendy Beekman and Els J. Faassen for the nutrient and toxin analysis.

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment., The authors acknowledge COST Action ES 1105 “CYANOCOST – Cyanobacterial blooms and toxins in water resources: Occurrence impacts and management” and COST Action ES 1201 “NETLAKE – Networking Lake Observatories in Europe” for contributing to this study through networking and knowledge sharing with European experts in the field. Evanthia Mantzouki was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation (SERI) to Bas Ibelings and by supplementary funding from University of Geneva. We thank Wendy Beekman for the nutrient analysis and the University of Wageningen for covering the costs of this analysis from the personal funding of dr. Miquel Lürling. We thank Pieter Slot for assisting with the pigment analysis and the University of Amsterdam for covering the costs of the analysis through funding from the group of Prof. Jef Huisman and dr. Petra Visser (IBED). We would like to thank the Environmental Data Initiative for covering the cost of archiving the EMLS dataset. We would like to thank the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Dept. of Experimental Limnology and the Aquatic Microbial Ecology Group for logistic and technical support of J. Fonvielle and H.-P. Grossart; and the Leibniz Association for financial support. The collection of data for Lough Erne and Lough Neagh were funded by the Department of Agriculture, Environment and Rural Affairs, Northern Ireland.

The aim of the study was to investigate variation in the structure of a population of Matteuccia struthiopteris (L.) Tod. in N–E Poland depending on its location in a river valley and light availability under tree canopies. Ordination statistical methods and structural equation modeling were used to identify ecological relationships in the population. The analysis showed that optimum growth conditions of M. struthiopteris depend on the canopy cover. As the shading increased, the size of trophophyllous leaves and the production of sporophylls decreased. The relationship between the canopy cover and the optimum growth conditions was best expressed by rootstock diameter and, to a lesser extent, by the number and height of trophophylls. An indirect relationship between the number and height of sporophylls and the canopy cover, by rootstock size and trophophyll quantity, was also identified. This relationship may be caused by the predominance of vegetative forms of reproduction. Based on the correlations between the landscape position vs. rootstock diameter and trophophyll height, a difference in the habitat colonization potential of M. struthiopteris could be detected. Three spatial clusters of M. struthiopteris in the river valley were identified: river bank, river terrace, river valley slopes. These relationships and the distribution of other herbaceous plant species occurring at the plots indicate that the distribution pattern of M. struthiopteris in the study area is determined by diverse environmental conditions, however mainly by light conditions.

The Vistula Lagoon, an estuarine system exposed to both continental and marine impacts, is marked by rapid changes in local environmental conditions, including salinity levels, water transparency, temperature, pH, dissolved oxygen concentrations, trophic state and wind speed. Here, the effect of environmental factors on the abundance and horizontal distribution of zooplankton was analysed. A higher number of taxa were noted in the saltwater intrusion section of the Vistula Lagoon (Central Basin) compared to the area of freshwater inflow (Western Basin). The average density of the analysed zooplankton in the western section of the Vistula Lagoon reached 654 indiv. dm−3, three-fold higher than in the central section (224 indiv. dm−3). Differences in zooplankton biomass were even more pronounced (13.43 mg dm−3 vs. 2.33 mg dm−3). The Central Basin of the Vistula Lagoon was dominated by Copepoda (approx. 50% total abundance), mostly Calanoida (genus Acartia) typically found in brackish waters. Marine species, including Acartia bifilosa and Acartia tonsa, were also reported. Species of freshwater Cladocera predominated in the Western Basin (over 50% total abundance, mostly the eutrophic species Chydorus sphaericus) where Copepoda were represented by a single cyclopoid species, Cyclops vicinus. The saline and freshwater environments of the Vistula Lagoon differed significantly (p

The study was conducted in a small (7.4 ha) peatland system with a humic lake concentrically surrounded by Sphagnum mat (Caricetum limosae) and Sphagnum bog (Ledo-Sphagnetum) in the Mazurian Lakeland in North-Eastern Poland. The peatland was situated in a forested catchment with a total area of 16.25 ha, and was influenced by surface drainage, artificially designed for forestry purposes. The content of zinc (Zn), cadmium (Cd), lead (Pb), copper (Cu) and hydrogen (H) ions was analysed in waters from precipitation, humic lake, mat, bog and surface outflow. The yearly budget of these ions, expressed as difference between atmospheric inflow and surface outflow, for the whole catchment was presented. The drainage of the peatland system over three years was accompanied by an increase in pH of lake, mat and bog waters. The whole catchment retention of H+ and trace metals studied decreased yearly in absolute values under these conditions. The peatland system began to leach Pb into surface waters and lost its ability to intercept Cd. These effects could be caused by intensity of outflow of water and sulphates and lowering of water storage. However, the potential to retain Zn and Cu ions was preserved.

The influence of land-use patterns on rotifer communities of streams in Masurian Lake District, Poland, was examined. Four streams in a forest-marsh area, two in forest-meadows, and two streams in agricultural areas were sampled monthly from March 1995 to October 1996. In all 41 genera and 139 species (i.e. ca. 30% of all rotifer species reported in Poland) were collected and identified, four of these are new to Poland.

Summary The aim of this work was to find out whether the difference between the central Vistula Lagoon (the southern Baltic Sea) and the western lagoon was reflected in the relationships between nutrients and phytoplankton during one-day hot summer conditions when the water temperature exceeded 20°C. Significant differences in Soluble Reactive Phosphorus (SRP) and Dissolved Inorganic Nitrogen (DIN) concentrations, and also in the biomass of the dominant phytoplankton assemblage of Cyanoprokaryota, were noted in the studied parts of the lagoon. No such differences were found for the nitrogen to phosphorus ratio (N:P) or for the biomasses of Bacillariophyta and Chlorophyta. The very low values of N:P (on average 2.8 and 3.4) indicated strong nitrogen limitation. The Correspondence Canonical Analysis (CCA) showed that the central part of the lagoon could be defined as positively related to DIN and to N:P, and western part could be characterized by correlation with temperature, dissolved oxygen and SRP concentrations. Competition for the limited resources of Dissolved Inorganic Nitrogen in the western, shallower part of the lagoon was in favour of Cyanoprokaryota, to the detriment of other phytoplankton assemblages. In contrast, the Cyanoprokaryota biomass in the central part of the lagoon, where DIN concentrations were increased, was lower, and Bacillariophyta in particular prospered at their expense. Here, the competition for Soluble Reactive Phosphorus was not so clear-cut.