A numerical study of forced lithospheric thinning

Subsolidus lithospheric thinning by mantle plumes may be involved in the creation of swells, hotspots, and rifts. Among the major questions concerning this process are the timescale on which it occurs and the structure of the plumes. The lithosphere is known to have been substantially thinned in 10 Ma or less. Current studies are focused on the lithospheric thinning by time-dependent plumes hypothesized to have large temperature differences across them

Antimicrobial resistance in enteric bacteria: Current state and next-generation solutions

Antimicrobial resistance is one of the largest threats to global health and imposes substantial burdens in terms of morbidity, mortality, and economic costs. The gut is a key conduit for the genesis and spread of antimicrobial resistance in enteric bacterial pathogens. Distinct bacterial species that cause enteric disease can exist as invasive enteropathogens that immediately evoke gastrointestinal distress, or pathobionts that can arise from established bacterial commensals to inflict dysbiosis and disease. Furthermore, various environmental reservoirs and stressors facilitate the evolution and transmission of resistance. In this review, we present a comprehensive discussion on circulating resistance profiles and gene mobilization strategies of the most problematic species of enteric bacterial pathogens. Importantly, we present emerging approaches toward surveillance of pathogens and their resistance elements as well as promising treatment strategies that can circumvent common resistance mechanisms

Previous Experiences with Epilepsy and Effectiveness of Information to Change Public Perception of Epilepsy

Differences with regard to the effectiveness of health information and attitude change are suggested between people with direct, behavioral experiences with a health topic and people with indirect, nonbehavioral experiences. The effects of three different methods of health education about epilepsy, frequently used in health education practice, are assessed in a pretest posttest design with control groups, controlling for experiences with epilepsy. Subjects were 132 students from teacher-training colleges. After all treatments, attitudes, and knowledge about epilepsy were changed in a positive way. Treatments were found to be equally effective. Before treatment, direct behavioral experiences were related to knowledge and a more positive attitude towards epilepsy. After treatment, subjects with direct behavioral experiences with epilepsy showed less change of attitude and knowledge as compared with subjects with indirect experiences. Direct experiences appear to restrain the processing of new information and attitude change

Impact of irreversibility and uncertainty on the timing of infrastructure projects

This paper argues that because of the irreversibility and uncertainty associated with Build - Operate - Transfer (BOT) infrastructure projects, their financial evaluation should also routinely include the determination of the value of the option to defer the construction start-up. This ensures that project viability is comprehensively assessed before any revenue or loan guarantees are considered by project sponsors to support the project. This paper shows that the framework can be used even in the context of the intuitive binomial lattice model. This requires estimating volatility directly from the evolution of the net operating income while accounting for the correlation between the revenue and costs functions. This approach ensures that the uncertainties usually associated with toll revenues, in particular, are thoroughly investigated and their impact on project viability is thoroughly assessed. This paper illustrates the usefulness of the framework with data from an actual (BOT) toll road project. The results show that by postponing the project for a couple of years the project turns out to be viable, whereas it was not without the deferral. The evaluation approach proposed therefore provides a better framework for determining when and the extent of government financial support, if any, that may be needed to support a BOT project on the basis of project economics. The analysis may also be applicable to private sector investment projects, which are characterized by irreversibility and a high rate of uncertainty

Screencasts: how effective are they and how do students engage with them?

The use of screencasts as an instructional technology is increasing rapidly in higher education. While there appears to be a consensus around students’ satisfaction with the provision of technology enhanced tools, there is limited evidence revolving around their impact in terms of knowledge acquisition. Moreover, the reasons why students choose to engage (or not) with these resources remain largely unreported. The study assessed the effect of using screencasts on undergraduate students’ understanding and engagement with learning material in one of their modules. Customised screencasts were used as optional additional learning and teaching resources. Grades obtained in a test module (with screencasts) and a control module (without screencasts) were compared to gauge the impact of screencasts on knowledge acquisition. Furthermore, the reasons for students’ engagement (or lack thereof) with the screencasts were explored using questionnaires. A modest but significant impact of screencasts on knowledge acquisition was found and students’ perception of the screencasts was overwhelmingly positive. Students suggested that screencasts should be kept short to summarise lectures or delve in-depth into complex concepts but should not replace whole lectures. Reasons for not using screencasts revolved around a lack of understanding of what the resources were but also a reported lack of fit between the nature of the tool and self-assessed learning style

Screencasts: how effective are they and how do students engage with them?

The use of screencasts as an instructional technology is increasing rapidly in higher education. While there appears to be a consensus around students’ satisfaction with the provision of technology enhanced tools, there is limited evidence revolving around their impact in terms of knowledge acquisition. Moreover, the reasons why students choose to engage (or not) with these resources remain largely unreported. The study assessed the effect of using screencasts on undergraduate students’ understanding and engagement with learning material in one of their modules. Customised screencasts were used as optional additional learning and teaching resources. Grades obtained in a test module (with screencasts) and a control module (without screencasts) were compared to gauge the impact of screencasts on knowledge acquisition. Furthermore, the reasons for students’ engagement (or lack thereof) with the screencasts were explored using questionnaires. A modest but significant impact of screencasts on knowledge acquisition was found and students’ perception of the screencasts was overwhelmingly positive. Students suggested that screencasts should be kept short to summarise lectures or delve in-depth into complex concepts but should not replace whole lectures. Reasons for not using screencasts revolved around a lack of understanding of what the resources were but also a reported lack of fit between the nature of the tool and self-assessed learning style

Genetically stable CRISPR-based kill switches for engineered microbes

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Genetically stable CRISPR-based kill switches for engineered microbes

Microbial biocontainment is an essential goal for engineering safe, next-generation living therapeutics. However, the genetic stability of biocontainment circuits, including kill switches, is a challenge that must be addressed. Kill switches are among the most difficult circuits to maintain due to the strong selection pressure they impart, leading to high potential for evolution of escape mutant populations. Here we engineer two CRISPR-based kill switches in the probiotic Escherichia coli Nissle 1917, a single-input chemical-responsive switch and a 2-input chemical- and temperature-responsive switch. We employ parallel strategies to address kill switch stability, including functional redundancy within the circuit, modulation of the SOS response, antibiotic-independent plasmid maintenance, and provision of intra-niche competition by a closely related strain. We demonstrate that strains harboring either kill switch can be selectively and efficiently killed inside the murine gut, while strains harboring the 2-input switch are additionally killed upon excretion. Leveraging redundant strategies, we demonstrate robust biocontainment of our kill switch strains and provide a template for future kill switch development

Thrilled to have “bagged a bargain” or “bitter” and “very frustrating”? Exploring consumer attitudes to value and deals in tourism

Similar to most global tourism markets, UK consumers adjusted their behavior during the global financial crisis, emphasizing value for money in travel choices. However, there is little evidence concerning consumers’ value-seeking behavior and especially how deals, discounts, and other sales promotions influence tourist decision making. This project explores concepts of value consciousness and deal proneness to shed light on attitudes toward monetary value in travel purchases. Using focus groups, the study found that deals and discounts frequently underpin some tourist choices, but that value consciousness is related to deal proneness, and interactions between the two could result in negative, positive, or mixed emotions. This relationship was captured through a dynamic categorization of tourists’ attitudes and behavior into four approaches to deals and value, namely, deals (1) as a way of life, (2) as a bonus, (3) as a problem, and (4) as toxic. The categories were dynamic in that individuals could move across them. The implications for tourism marketers are outlined