From TgO/GABA-AT, GABA, and T-263 mutant to conception of Toxoplasma

Toxoplasma gondii causes morbidity, mortality, and disseminates widely via cat sexual stages. Here, we find T. gondii ornithine aminotransferase (OAT) is conserved across phyla. We solve TgO/GABA-AT structures with bound inactivators at 1.55 Å and identify an inactivator selective for TgO/GABA-AT over human OAT and GABA-AT. However, abrogating TgO/GABA-AT genetically does not diminish replication, virulence, cyst-formation, or eliminate cat’s oocyst shedding. Increased sporozoite/merozoite TgO/GABA-AT expression led to our study of a mutagenized clone with oocyst formation blocked, arresting after forming male and female gametes, with “Rosetta stone”-like mutations in genes expressed in merozoites. Mutations are similar to those in organisms from plants to mammals, causing defects in conception and zygote formation, affecting merozoite capacitation, pH/ionicity/sodium-GABA concentrations, drawing attention to cyclic AMP/PKA, and genes enhancing energy or substrate formation in TgO/GABA-AT-related-pathways. These candidates potentially influence merozoite’s capacity to make gametes that fuse to become zygotes, thereby contaminating environments and causing disease

Designing fixed-bed adsorbers to remove mixtures of organics

A liquid-phase granular activated carbon (GAC) pilot plant and a full-scale GAC adsorber were designed, built, and operated in order to evaluate their performance for treating a groundwater contaminated with several volatile and synthetic organic chemicals. Several empty bed contact times (EBCTs) ranging from 1 to 30 min were used during the pilot-plant study, and a simple method for evaluating the GAC use rate as a function of EBCT was developed and demonstrated for dichloroethene and trichloroethene (TCE). Pilot-plant data were compared with the pore surface diffusion model, which considers external and internal mass transfer mechanisms of pore and surface diffusion. Natural organic matter in the water was found to decrease GAC capacity and kinetics for TCE

Purchasing products with sustainable palm oil: designing and evaluating an online intervention for Australian consumers

Widespread tropical deforestation and biodiversity loss in Southeast Asia due to the oil palm industry can be addressed by encouraging consumers to purchase sustainable palm oil (SPO). An online experiment was conducted to assess whether addressing barriers relating to education, motivation and product availability would increase purchasing of SPO. Australian adults (n = 628) were randomly assigned to either: (1) a newly developed interactive educational website on palm oil and SPO; (2) an existing educational video on SPO; or (3) an interactive website on differentiating between real and fake news (an attentional control condition). All participants completed pre-intervention and immediate post-intervention measures. Most participants (n = 403) completed follow-up measures two weeks later. Multivariate analysis revealed that the interactive website and educational video increased both knowledge and the intention to purchase SPO (compared to the attentional control), but neither significantly impacted follow-up self-reported SPO purchasing behaviour. Low perceived product availability might help explain the intention–behaviour gap. Our results suggest that, in addition to increasing consumer knowledge and motivation, promoting sustainable consumption requires creating opportunities for people to engage in the desired behaviour