Facilitated transport of diuron and glyphosate in high copper vineyard soils

The fate of organic herbicides applied to agricultural fields may be affected by other soil amendments, such as copper applied as a fungicide. The effect of copper on the leaching of diuron and glyphosate through a granitic and a calcareous soil was studied in the laboratory using sieved-soil columns. Each soil was enriched with copper sulfate to obtain soil copper concentrations of 125, 250, 500, and 1000 mg kg(-1). Glyphosate leaching was influenced by soil pH and copper concentration, whereas diuron leaching was not. In the calcareous soil, glyphosate leaching decreased as copper levels increased from 17 mg kg(-1) (background) to 500 mg kg(-1). In the granitic soil, glyphosate leaching increased as copper levels increased from 34 mg kg(-1) (background) to 500 mg kg(-1). The shapes of the copper elution curves in presence of glyphosate were similar to shapes of the glyphosate curves, suggesting the formation of Cu-glyphosate complexes that leach through the soil. Soil copper concentration does not influence diuron leaching. In contrast, increasing copper concentrations reduces glyphosate leaching through calcareous soils, and conversely, increases glyphosate leaching through granitic soils. Our findings suggest that the risk of groundwater contamination by glyphosate increases in granitic soils with elevated copper concentrations.     

Controlling Enzymatic Activity by Modulating the Oligomerization State via Chemical Rescue and Optical Control

Selective switching of enzymatic activity has been a longstanding goal in synthetic biology. Drastic changes in activity upon mutational manipulation of the oligomerization state of enzymes have frequently been reported in the literature, but scarcely exploited for switching. Using geranylgeranylglyceryl phosphate synthase as a model, we demonstrate that catalytic activity can be efficiently controlled by exogenous modulation of the association state. We introduced a lysine-to-cysteine mutation, leading to the breakdown of the active hexamer into dimers with impaired catalytic efficiency. Addition of bromoethylamine chemically rescued the enzyme by restoring hexamerization and activity. As an alternative method, we incorporated the photosensitive unnatural amino acid o-nitrobenzyl-O-tyrosine (ONBY) into the hexamerization interface. This again led to inactive dimers, but the hexameric state and activity could be recovered by UV-light induced cleavage of ONBY. For both approaches, we obtained switching factors greater than 350-fold, which compares favorably with previously reported activity changes that were caused by site-directed mutagenesis.     

Video connecting families and social robots: from ideas to practices putting technology to work

Technology use is a socially embedded process, especially when it comes to older adults and care. However, the restrictions associated with the COVID-19 pandemic have limited social contact to protect vulnerable groups in care homes, and even if technology use has increased in other areas, there is little known about the potential uptake of communication technology and changes in social interaction in the care context during a lasting crisis. This paper explores changes in communication technology use triggered by the pandemic at two care homes, using a qualitative diary study, online interviews and observations, and in-situ interviews within the care home with residents and workers. Our findings point to increasing use of tablets and video conference software triggered by COVID-related experiences, with implications for living and working in care homes. We also characterise the isolation experience of the residents, the workers’ concerns about the residents and changes in social interaction. We observed new areas of technology usage, associated changing work practices, technical affinity issues and context-specific attitudes towards future technologies. While the pandemic has triggered the use of communication technology in care homes on a small scale, this has also caused increasing workload and in particular articulation work, which requires support structures and the re-definition of work roles.

     

Assembling three one-camera images for three-camera intersection classification

Determining whether an autonomous self-driving agent is in the middle of an intersection can be extremely difficult when relying on visual input taken from a single camera. In such a problem setting, a wider range of views is essential, which drives us to use three cameras positioned in the front, left, and right of an agent for better intersection recognition. However, collecting adequate training data with three cameras poses several practical difficulties; hence, we propose using data collected from one camera to train a three-camera model, which would enable us to more easily compile a variety of training data to endow our model with improved generalizability. In this work, we provide three separate fusion methods (feature, early, and late) of combining the information from three cameras. Extensive pedestrian-view intersection classification experiments show that our feature fusion model provides an area under the curve and F1-score of 82.00 and 46.48, respectively, which considerably outperforms contemporary three- and one-camera models.     

Oligomer Dynamics of LL-37 Truncated Fragments Probed by α-Hemolysin Pore and Molecular Simulations

Oligomerization of antimicrobial peptides (AMPs) is critical in their effects on pathogens. LL-37 and its truncated fragments are widely investigated regarding their structures, antimicrobial activities, and application, such as developing new antibiotics. Due to the small size and weak intermolecular interactions of LL-37 fragments, it is still elusive to establish the relationship between oligomeric states and antimicrobial activities. Here, an α-hemolysin nanopore, mass spectrometry (MS), and molecular dynamic (MD) simulations are used to characterize the oligomeric states of two LL-37 fragments. Nanopore studies provide evidence of trapping events related to the oligomer formation and provide further details on their stabilities, which are confirmed by MS and MD simulations. Furthermore, simulation results reveal the molecular basis of oligomer dynamics and states of LL-37 fragments. This work provides unique insights into the relationship between the oligomer dynamics of AMPs and their antimicrobial activities at the single-molecule level. The study demonstrates how integrating methods allows deciphering single molecule level understanding from nanopore sensing approaches.