No clear response in the stormwater phytoplankton community to biocide contamination

This study investigated the responses of natural phytoplankton communities of an urban stormwater pond to biocide contamination. The biocides carbendazim, terbutryn, diuron, and irgarol 1051, and their mixture, were used in two laboratory microcosm and one outdoor mesocosm studies at concentrations of 10, 100, and 1000 ng L−1. The water samples were collected in a pond receiving significant biocide contamination. The mesocosm study was carried out in the same pond. The phytoplankton community response was evaluated after 10–15 days of exposure, with respect to its taxonomic composition, abundance and biovolume. No significant changes were observed in any of the experiments. Only at the highest applied terbutryn concentration were lower numbers of taxa identified in both microcosm and mesocosm experiments. Additionally, increases in Chlorophyta abundance and biovolume, along with an increase in irgarol concentration, were observed throughout the three experiments. Nevertheless, the statistical analysis did not confirm any significant differences among the biocide treatments. These results suggest that the biocide concentrations probably were below the harmful or toxic threshold to the stormwater pond phytoplankton. On the other hand, as the investigated pond phytoplankton taxa face biocide inputs throughout the year, they could have already adapted to the tested biocide contamination

Relationship between Polycyclic Aromatic Hydrocarbons in Sediments and Invertebrates of Natural and Artificial Stormwater Retention Ponds

Sediments and invertebrates were sampled from 9 stormwater retention ponds (SWRPs) and 11 natural, shallow lakes in Denmark. Samples were analyzed for 13 polycyclic aromatic hydrocarbons (PAHs). The SWRPs received urban and highway runoff from various types of drainage areas and the lakes were located in areas of various land uses. Comparing PAHs in the sediments of the SWRPs and the lakes, it was found that levels of total PAH were similar in the two aquatic systems, with median values of 0.94 and 0.63 mg·(kg·DM)−1 in sediments of SWRPs and lakes, respectively. However, the SWRP sediments tended to have higher concentrations of high-molecular-weight PAHs than the lakes. A similar pattern was seen for PAHs accumulated in invertebrates where the median of total PAH was 2.8 and 2.1 mg·(kg·DM)−1 for SWRPs and lakes, respectively. Principal component analysis on the PAH distribution in the sediments and invertebrates showed that ponds receiving highway runoff clustered with lakes in forests and farmland. The same was the case for some of the ponds receiving runoff from residential areas. Overall, results showed that sediment PAH levels in all SWRPs receiving runoff from highways were similar to the levels found in some of the investigated natural, shallow lakes, as were the sediment PAH levels from some of the residential SWRPs. Furthermore, there was no systematic trend that one type of water body exceeded environmental quality standards (EQS) values more often than others. Together this indicates that at least some SWRPs can sustain an invertebrate ecosystem without the organisms experiencing higher bioaccumulation of PAHs then what is the case in shallow lakes of the same region

A setup for studies of photoelectron circular dichroism from chiral molecules in aqueous solution

We present a unique experimental design that enables the measurement of photoelectron circular dichroism (PECD) from chiral molecules in aqueous solution. The effect is revealed from the intensity difference of photoelectron emission into a backward-scattering angle relative to the photon propagation direction when ionizing with circularly polarized light of different helicity. This leads to asymmetries (normalized intensity differences) that depend on the handedness of the chiral sample and exceed the ones in conventional dichroic mechanisms by orders of magnitude. The asymmetry is largest for photon energies within several electron volts above the ionization threshold. A primary aim is to explore the effect of hydration on PECD. The modular and flexible design of our experimental setup EASI (Electronic structure from Aqueous Solutions and Interfaces) also allows for detection of more common photoelectron angular distributions, requiring distinctively different detection geometries and typically using linearly polarized light. A microjet is used for liquid-sample delivery. We describe EASI’s technical features and present two selected experimental results, one based on synchrotron-light measurements and the other performed in the laboratory, using monochromatized He-II α radiation. The former demonstrates the principal effectiveness of PECD detection, illustrated for prototypic gas-phase fenchone. We also discuss the first data from liquid fenchone. In the second example, we present valence photoelectron spectra from liquid water and NaI aqueous solution, here obtained from a planar-surface microjet (flatjet). This new development features a more favorable symmetry for angle-dependent photoelectron measurements

Conceptualizing a distributed, multi-scalar global public sphere through activist communication practices in the World Social Forum

This article contributes to debate about how to conceptualize the global public sphere. Drawing on media practice theory and ethnographic research on media activism in the World Social Forum, it shows how ‘global publics’ can be constituted through a diverse range of activist communication practices that complicate both conventional hierarchies of scale and contemporary theorizations of publics as personalized networks. It develops an understanding of the global public sphere as an emergent formation made up of multiple, interlinked publics at different scales and emphasizes the significance of collective communication spaces for actors at the margins of the global network society

Reduction of acute respiratory infections in day-care by non-pharmaceutical interventions: a narrative review

ObjectiveChildren who start in day-care have 2–4 times as many respiratory infections compared to children who are cared for at home, and day-care staff are among the employees with the highest absenteeism. The extensive new knowledge that has been generated in the COVID-19 era should be used in the prevention measures we prioritize. The purpose of this narrative review is to answer the questions: Which respiratory viruses are the most significant in day-care centers and similar indoor environments? What do we know about the transmission route of these viruses? What evidence is there for the effectiveness of different non-pharmaceutical prevention measures?DesignLiterature searches with different terms related to respiratory infections in humans, mitigation strategies, viral transmission mechanisms, and with special focus on day-care, kindergarten or child nurseries, were conducted in PubMed database and Web of Science. Searches with each of the main viruses in combination with transmission, infectivity, and infectious spread were conducted separately supplemented through the references of articles that were retrieved.ResultsFive viruses were found to be responsible for ≈95% of respiratory infections: rhinovirus, (RV), influenza virus (IV), respiratory syncytial virus (RSV), coronavirus (CoV), and adenovirus (AdV). Novel research, emerged during the COVID-19 pandemic, suggests that most respiratory viruses are primarily transmitted in an airborne manner carried by aerosols (microdroplets).ConclusionSince airborne transmission is dominant for the most common respiratory viruses, the most important preventive measures consist of better indoor air quality that reduces viral concentrations and viability by appropriate ventilation strategies. Furthermore, control of the relative humidity and temperature, which ensures optimal respiratory functionality and, together with low resident density (or mask use) and increased time outdoors, can reduce the occurrence of respiratory infections

Understanding micro-processes of community building and mutual learning on Twitter: a ‘small data’ approach

This article contributes to an emerging field of ‘small data’ research on Twitter by presenting a case study of how teachers and students at a sixth-form college in the north of England used this social media platform to help construct a ‘community of practice’ that enabled micro-processes of recognition and mutual learning. Conducted as part of a broader action research project that focused on the ‘digital story circle’ as a site of, and for, narrative exchange and knowledge production, this study takes the form of a detailed analysis of a departmental Twitter account, combining basic quantitative metrics, close reading of selected Twitter data and qualitative interviews with teachers and students. Working with (and sometimes against) Twitter's platform architecture, teachers and students constructed, through distinct patterns of use, a shared space for dialogue that facilitated community building within the department. On the whole, they were able to overcome justified anxieties about professionalism and privacy; this was achieved by building on high levels of pre-existing trust among staff and by performing that mutual trust online through personal modes of communication. Through micro-processes of recognition and a breaking down of conventional hierarchies that affirmed students' agency as knowledge producers, the departmental Twitter account enabled mutual learning beyond curriculum and classroom. The significance of such micro-processes could only have been uncovered through the detailed scrutiny that a ‘small data’ approach to Twitter, in supplement to some obvious virtues of Big Data approaches, is particularly well placed to provide

Estimation of genetic parameters for feed efficiency traits using random regression models in dairy cattle.

Feed efficiency has become an increasingly important research topic in recent years. As feed costs rise and the environmental impacts of agriculture become more apparent, improving the efficiency with which dairy cows convert feed to milk is increasingly important. However, feed intake is expensive to measure accurately on large populations, making the inclusion of this trait in breeding programs difficult. Understanding how the genetic parameters of feed efficiency and traits related to feed efficiency vary throughout the lactation period is valuable to gain understanding into the genetic nature of feed efficiency. This study used 121,226 dry matter intake (DMI) records, 120,500 energy corrected milk (ECM) records, and 98,975 metabolic body weight (MBW) records, collected on 7,440 first lactation Holstein cows from 6 countries (Canada, Denmark, Germany, Spain, Switzerland, and United States of America), from January 2003 to February 2022. Genetic parameters were estimated using a multiple-trait random regression model with a fourth order Legendre polynomial for all traits. Weekly phenotypes for DMI were re-parameterized using linear regressions of DMI on ECM and MBW, creating a measure of feed efficiency that was genetically corrected for ECM and MBW, referred to as genomic residual feed intake (gRFI). Heritability (SE) estimates varied from 0.15 (0.03) to 0.29 (0.02) for DMI, 0.24 (0.01) to 0.29 (0.03) for ECM, 0.55 (0.03) to 0.83 (0.05) for MBW, and 0.12 (0.03) to 0.22 (0.06) for gRFI. In general, heritability estimates were lower in the first stage of lactation compared with the later stages of lactation. Additive genetic correlations between weeks of lactation varied, with stronger correlations between weeks of lactation that were close together. The results of this study contribute to a better understanding of the change in genetic parameters across the first lactation, providing insight into potential selection strategies to include feed efficiency in breeding programs