Recognizing and mainstreaming pertinent walkability elements into the university campus planning is crucial to materialise green mandates of the campus, while enhancing social and economic sustainability. In one of such attempts, this transverse study investigated the walking motivations, built environment factors associated with campus walkability and the relative importance of the studied built environment factors in reference to the sociodemographic attributes from the viewpoint of the campus community in a tropical university campus in Kuala Lumpur, Malaysia. An online survey using a structured questionnaire was conducted between May and September 2019. The built environment factors associated with campus walkability were expressed and ranked as adjusted scores (AS). Meanwhile, multivariable logistic regression was deployed to examine the relative importance of the studied built environment factors in reference to the sociodemographic attributes of the campus community. Among 504 total responses acquired, proximity between complementary land uses (90.7%) was reported as the main motivation for walking. On the other hand, street connectivity and accessibility (AS 97.62%) was described as the most opted built environment factor, followed by land use (AS 96.76%), pedestrian infrastructure (AS 94.25%), walking experience (AS 87.07%), traffic safety (AS 85.28%) and campus neighbourhood (AS 59.62%), respectively. Among the sociodemographic attributes, no regular monthly income (OR = 3.162; 95% CI = 1.165-8.379; p less then 0.05) and willingness to walk more than 60 min inside the campus per day (OR = 0.418; 95% CI = 0.243-0.720; p less then 0.05) were significantly associated with the expression of higher importance towards the reported built environment factors in the multivariate analysis. In brief, the findings of this study were envisaged to elicit valuable empirical evidence for informed interventions and strengthening campus sustainable mobility policies.A novel method based on relational analysis is presented for assessing the performance of conventional oil exploitation and its environmental implications, with a focus on the energy-water nexus. It considers the energy system as a metabolic network and integrates various factors relevant for technical, economic and environmental processes, thus avoiding some of the simplifications inherent in conventional approaches to the assessment of primary resource quality, such as economic cost-benefit analysis (CBA) and the energy return on investment (EROI). Relational analysis distinguishes between functional (notional) and structural (tangible) elements in the metabolic network, which allows a simultaneous characterization and geo-localization of the exploitation process across different scales and dimensions of analysis. Key aspects of the approach are illustrated with data from the Ecuadorian oil sector spanning the period 1972-2018. It is shown that by establishing a relation among the characteristics of the exploited oil fields (oil typology, age of field) and those of the exploitation process (requirement of energy carriers, labor, freshwater and power capacity and generation of greenhouse gases and oil-produced water), changes in the performance and environmental implications of the oil extraction system can be characterized at different points in space and time.Clostridium tyrobutyricum is a promising microbial cell factory to produce biofuels. In this study, an uptake hydrogenase (hyd2293) from Ethanoligenens harbinense was overexpressed in C. tyrobutyricum and significantly affected the redox reactions and metabolic profiles. Compared to the parental strain (Ct-WT), the mutant strain Ct-Hyd2293 produced ~34% less butyrate, ~148% more acetate, and ~11% less hydrogen, accompanied by the emerging genesis of butanol. Comparative transcriptome analysis revealed that 666 genes were significantly differentially expressed after the overexpression of hyd2293, including 82 up-regulated genes and 584 down-regulated genes. The up-regulated genes were mainly involved in carbohydrate and energy metabolisms while the down-regulated genes were distributed in nearly all pathways. Genes involved in glucose transportation, glycolysis, different fermentation pathways and hydrogen metabolism were studied and the gene expression changes showed the mechanism of the metabolic flux redistribution in Ct-Hyd2293. The overexpression of uptake hydrogenase redirected electrons from hydrogen and butyrate to butanol. The key enzymes participating in the energy conservation and sporulation were also identified and their transcription levels were generally reduced. This study demonstrated the transcriptomic responses of C. tyrobutyricum to the expression of a heterologous uptake hydrogenase, which provided a better understanding of the metabolic characteristics of C. tyrobutyricum and demonstrated the potential role of redox manipulation in metabolic engineering for biofuel productions.Modelling of partial nitrification process is affected by several factors such as selection of true substrates, FA and FNA inhibition, and pH effect on growth rate. Among these factors, the selection of true substrates is very critical as it affects the structure of the model. https://www.selleckchem.com/products/tacrine-hcl.html In the present work, a new model adopting free ammonia (FA) and free nitrous acids (FNA) as the true substrate for ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) was proposed. Then the proposed model was compared with two reported models which adopted ammonium and nitrite, and FA and nitrite as the true substrate for AOB and NOB, respectively. The three mathematical models were compared in terms of predicted minimum dissolved oxygen (DO) in response to varied solids retention time (SRT) (10-30 d), pH (7-8.5), and temperature (10-35 °C). The input kinetic values were justified and updated based on statistical analysis of literature data. Adopting FA as the true substrate increased the minimum DO for AOB. Further, experimental data from different literature studies were taken for model simulation and comparison. Inconsistency was observed between the model prediction and literature data for all three models. The model that adopted ammonium and nitrite as the true substrate for AOB and NOB had better consistency with literature data than other two models. The affecting factors for the model prediction was classified into three levels and discussed in detail. Future work was proposed. The results of this study provide valuable information for the design and modelling of partial nitrification process.