Effects of the Algal Toxin Microcystin on Fishes in the James River, Virginia

With the global rise in frequency of harmful algal blooms in estuarine environments comes an increase in prevalence of toxic metabolites, such as microcystin (MC), that some of the cyanobacteria involved will produce. At high concentrations, MC may accumulate in consumer tissues and have deleterious effects on organisms; however impacts of the toxin on aquatic living resources at ecologically relevant concentrations have not been widely documented. We analyzed the effects of MC on juveniles of five fish species from the James River, Virginia to determine if MC has the potential to impede growth. Using three separate experimental approaches, it was shown that exposure to concentrations of the toxin currently observed in the James River estuary do not appear to significantly impact the growth or survivorship of tested fish species. Extraneous factors in parts of the study led to an inability to draw clear conclusions on mortality or growth impacts; however it is evident from the experiments that at least some of the fish species have biological mechanisms in place that allow them to effectively eliminate the toxin from their systems. An ability to extricate the toxin suggests the possibility for fishes to withstand MC exposures and sustain few negative health impacts at low MC concentrations

Virtual manhood acts within social networks: The enactment of toxic masculinity on Reddit

Toxic masculinity (TM) has emerged as a label for the western hegemonic masculine ideal, which is generally defined by the pressure for boys and men to be aggressive and dominant, restrict emotional expression, and marginalize women and others that do not adhere to these values (Connell & Messerschmidt, 2005; Kupers, 2005). This phenomenon increases the risk for male identified individuals to engage in general acts of bigotry, especially gender-based violence (APA, 2018; Baugher & Gazmararian, 2015; FBI, 2007; Feder, Levant, & Dean, 2010). A contemporary touchpoint associated with proliferating TM ideologies is participation in online anonymous “toxic technoculture” social network communities (Massanari, 2017; Salter, 2018). A timely investigation was conducted by Moloney and Love (2018) that explored the enactments of masculinity in virtual online spaces. They subsequently introduced the concept of Virtual Manhood Acts (VMA) which provides a framework to understand how masculinity is observed online. VMA were characterized as behaviors enacted to maintain a heterosexist environment and to oppress women and others in virtual social spaces. Prior to this study there was limited empirical understanding of how problematic and toxic enactments of masculinity, evident in society, are also enacted in virtual spaces. This study addresses the call to investigate enactments of VMA on other online social platforms. This qualitative investigation of the enactment of VMA was conducted on Reddit, the most popular social network website and seventh most trafficked website in North America (Hardwick, 2020, May 9). Data was captured before and after two publicized mass femicide events from two Manosphere connected Reddit community forums (r/IncelsWithoutHate & r/MensRights). The identified forums have been implicated as featuring misogynistic and bigoted ideological posts. Data was analyzed utilizing the a priori concept of VMA and a modified constructivist grounded theory approach (Charmaz, 2014). This hybrid deductive and inductive approach allowed for identifiable, novel, and divergent themes of manhood enactments to emerge. The results and implications of this study are discussed with select psychological frameworks and other fields of study in mind

Topography data harmonisation and uncertainties applying SRTM, laser scanner and cartographic elevation models

International audienceOnly a few studies have attempted to quantify topography-depending water fluxes, to evaluate retention and reservoir capacities and surface run-off paths within large river basins because data availability and data quality are critical issues to face this objective. It becomes most relevant if water balance has to be calculated in large or transboundary river basins. The advance of space based earth observation data offers a solution to this information problem. Therefore, this paper mainly focuses on weaknesses and strengths analyzing topography with SRTM (Shuttle Radar Topography Mission) digital height data and thus provides techniques for their improved application in river network derivation, floodplain analysis, watershed hydrology in large as well as in large river basins (>1000 km2). In the analysis different types of digital elevation models (DEM), terrain models (DTM) and land cover classification data (biotope map, Corine Land Cover 1994) have been used. The DHMs are generated from Airborne Laser Scanning (0.5 m), topographic maps (10.0/50.0 m) and SRTM at 30.0 m and 90.0 m spatial resolution. SRTM digital height models are generated by Synthetic Aperture Radar (SAR) and show a high spatial variance in urban areas, regions of dense vegetation canopy, floodplains and water bodies. As study area serve the Elbe basin (Czech Republic, Germany) with its sub-basins and the Saale river basin (Germany, different federal countries Saxony-Anhalt, Saxony and Thuringia)

Actors and factors - bridging social science findings and urban land use change modeling

Recent uneven land use dynamics in urban areas resulting from demographic change, economic pressure and the cities’ mutual competition in a globalising world challenge both scientists and practitioners, among them social scientists, modellers and spatial planners. Processes of growth and decline specifically affect the urban environment, the requirements of the residents on social and natural resources. Social and environmental research is interested in a better understanding and ways of explaining the interactions between society and landscape in urban areas. And it is also needed for making life in cities attractive, secure and affordable within or despite of uneven dynamics.\ud The position paper upon “Actors and factors – bridging social science findings and urban land use change modeling” presents approaches and ideas on how social science findings on the interaction of the social system (actors) and the land use (factors) are taken up and formalised using modelling and gaming techniques. It should be understood as a first sketch compiling major challenges and proposing exemplary solutions in the field of interest

Shaping nanoparticle fingerprints at the interface of cholesteric droplets

The ordering of nanoparticles into predetermined configurations is of importance to the design of advanced technologies. In this work, we moderate the surface anchoring against the bulk elasticity of liquid crystals to dynamically shape nanoparticle assemblies at a fluid interface. By tuning the degree of nanoparticle hydrophobicity with surfactants that alter the molecular anchoring of liquid crystals, we pattern nanoparticles at the interface of cholesteric liquid crystal emulsions. Adjusting the particle hydrophobicity more finely further modifies the rigidity of assemblies. We establish that patterns are tunable by varying both surfactant and chiral dopant concentrations. Since particle assembly occurs at the interface with the desired structures exposed to the surrounding phase, we demonstrate that particles can be readily crosslinked and manipulated, forming structures that retain their shape under external perturbations. This study establishes the templating of nanomaterials into reconfigurable arrangements. Interfacial assembly is tempered by elastic patterns that arise from the geometric frustration of confined cholesterics. This work serves as a basis for creating materials with chemical heterogeneity and with linear, periodic structures, essential for optical and energy applications.Comment: 16 pages with 5 figures, 4 page supplementary with 5 supplementary figure

Guest Editorial: The Elderly Reader of the Future--Need We Be Concerned?

Letter from the editor

Homiletics

Homiletics