Are two resources really better than one? Some unexpected results of the availability of substitutes

The possibility of exploiting multiple resources is usually regarded as positive from both the economic and the environmental point of view. However, resource switching may also lead to unsustainable growth and, ultimately, to an equilibrium condition which is worse than the one that could have been achieved with a single resource. We developed a dynamic model where users exploit multiple resources and have different levels of preference among them. In this setting, exploiting multiple resources leads to worse outcomes in both economic and ecological terms than the single resource case under a wide range of parameter configurations. Our arguments are illustrated using two empirical situations, namely oil drilling in the North Sea and whale hunting in the Antarctic.     

Aptamers are an innovative and promising tool for phytoplankton taxonomy and biodiversity research

Nucleic acid aptamers are small-size ligands that selectively bind to molecular segments even when they protrude from cell surfaces. Due to their high specificity, aptamers are widely used in biomedical research and as probes for different applications. Here, we tested whether aptamers can also discriminate among phytoplankton cells. As a proof of concept we focused on the widespread centric diatom Leptocylindrus danicus and generated two aptamers that selectively bind to its cell surface. The aptamers did not bind to other diatoms tested, which included both pennate (Pseudo-nitzschia multistriata) and centric (Skeletonema marinoi, Chaetoceros socialis) species. They also showed negative binding to closely related species (Tenuicylindrus belgicus, Leptocylindrus aporus, Leptocylindrus convexus), which are hardly recognizable with microscopy techniques. In addition, aptamers discriminated also among cells of the same clone, suggesting a potential use of aptamers as clone-specific/stage-specific probes to track phytoplankton life stages in their natural environment. While the method still needs to be tested with natural algal samples, it can complement in a unique way the existing approaches to discriminate among species and possibly life stages of marine phytoplankton. The method can find useful application in taxonomic and ecological studies as well as in environmental monitoring including early warning strategies.     

Governing water in federal river basins

Regional Environmental Change -     

The effect of landscape type and landscape elements on public visual preferences: ways to use knowledge in the context of landscape planning

This study deals with an assessment of the visual quality of landscapes, and specifically with the perception of selected elements in the landscape. The aim of the study was to find out how particular elements are perceived in various landscape types, whether this perception is affected by the landscape type in which the elements are placed, and to what extent the respondents’ characteristics affect the assessment. The study was carried out with a sample of respondents of various ages, educational levels and types of employment. The respondents came from Slovakia and the Czech Republic. The preferences of the respondents were determined using an online questionnaire, in which they rated landscape photographs on a 21 point rating scale with a range from ?10 to +10 points. Using generalised linear mixed effect models, it was found that the perception of an element is most affected by the landscape type, since the same element was assessed differently according to the landscape in which it was situated. The results confirmed that selected elements which do not disturb the harmony of the landscape are generally positively perceived, and the selected elements of a technical character are generally negatively perceived. Among the characteristics of the respondents, only gender and the respondent's current place of residence have an effect on their visual preferences.     

Developing strategies for managing construction and demolition wastes in Malaysia based on the concept of circular economy

Construction and demolition (C&D) waste is a pressing issue not only in Malaysia, but it is also a worldwide concern including the developed countries as well. C&D waste should be managed throughout the construction cycle. The concept of circular economy (CE) is an emerging notion that has the potential to be utilized as waste minimization approach. This paper aims to assess the potentials of incorporating the CE concept as an approach to minimizing C&D wastes, by developing a CE-based theoretical framework for C&D waste management in Malaysia. In line with this objective, a systematic review has been conducted to determine how CE can be operationalised as a strategy to minimize wastes, while considering it as a key factor for mitigating the environmental impacts. Based on the literature review, a CE-based theoretical framework has been proposed using Malaysia as a case study. The framework has been developed following a three-layer approach namely micro-, meso-, and macro-levels. Waste minimization strategies have been identified for each level taking into account the main stages in the construction industry, i.e., planning, designing, procurement, construction, and demolition. The different stakeholders involved at each stage and their interactions in the stages have also been identified.     

Domestic violence shapes Colombian women’s partner choices

Behavioral Ecology and Sociobiology - Honey bee colonies require adequate pollen for maintenance and growth. Pollens vary in nutritional value, and a balanced diet is achieved by mixing pollens...     

Preliminary study on persistence in soil and residues in maize of imidacloprid

The aim of this work was to study the distribution of imidacloprid in soil and its translocation to roots and aerial parts of maize plant. The main objective was to assess imidacloprid residues in field environment, in order to provide data on honeybees exposure level to such an active substance. Imidacloprid has been detected and quantified by Triple Quadrupole HPLC-MS-MS. Pesticide persistence in the soil and its residues in pollen and in maize plants have been evaluated during the growing of maize plants developed from seeds dressed with Gaucho 350 FS (imidacloprid: 1.0 mg/seed). The sowing has been performed by means of a pneumatic precision drill. Samples have been collected at 30, 45, 60, 80, 130 days after the sowing, as pollen samples have been collected at the tasseling. Imidacloprid presence in aerial part of maize plant declined to 2-3 μg/kg 80 days after the sowing, while concentration in kernel at harvest was <1 μg/kg. Maize pollen represents an important part of protein supply of beehives, and it is of critical importance to bee foraging. The values detected (imidacloprid residues <1 μg/kg) showed that maize pollen source should not be relevant for acute toxicity impact on honey bees.