161 research outputs found
Recommended from our members
Disclosure of Positive and Negative Experiences as Social Utility
We propose that disclosing oneâs positive and negative experiences carries social utility for both senders and recipients. We show that consumers consider this utility when deciding whether to disclose their experiences with others. In three preregistered studies, consumers respond in kind to the disclosures of positive and negative experiences by others
A retrospective time trend study of firearm and nonfirearm homicide in Cape Town from 1994 to 2013
Background. Gunshot injuries from interpersonal violence are a major cause of mortality. In South Africa (SA), the Firearms Control Act of 2000 sought to address firearm violence by removing illegally owned firearms from circulation, stricter regulation of legally owned firearms, and stricter licensing requirements. Over the last few years, varied implementation of the Act and police corruption have increased firearm availability.Objectives. To investigate whether changes in firearm availability in SA were associated with changes in firearm homicide rates.Methods. This was a retrospective time trend study (1994 - 2013) using postmortem data. Time trends of firearm and non-firearm homicide rates were analysed with generalised linear models. Distinct time periods for temporal trends were assigned based on a priori assumptions regarding changes in the availability of firearms.Results. Firearm and non-firearm homicide rates adjusted for age, sex and race exhibited different temporal trends. Non-firearm homicide rates either decreased or remained stable over the entire period. Firearm homicide increased at 13% annually from 1994 through 2000, and decreased by 15% from 2003 through 2006, corresponding with changes in firearm availability in 2001, 2003, 2007 and 2011. A 21% annual increase in firearm homicide after 2010 coincided with police fast-tracking new firearm licence applications. Cape Townâs coloured population experienced a significantly greater increase than other population groups following additional exposure to illegal firearms from 2007.Conclusions. The strong association between firearm availability and homicide, and the reversal of a decreasing firearm homicide trend during a period of lax enforcement, provide further support for the association between reduced firearm homicide and stricter regulation
Analysis of the galactomannan binding ability of β-mannosidases, BtMan2A and CmMan5A, regarding their activity and synergism with a β-mannanase
Both β-mannanases and β-mannosidases are required for mannan-backbone degradation into mannose. In this study, two β-mannosidases of glycoside hydrolase (GH) families 2 (BtMan2A) and 5 (CmMan5A) were evaluated for their substrate specificities and galactomannan binding ability. BtMan2A preferred short manno-oligomers, while CmMan5A preferred longer ones; DP >2, and galactomannans. BtMan2A displayed irreversible galactomannan binding, which was pH-dependent, with higher binding observed at low pH, while CmMan5A had limited binding. Docking and molecular dynamics (MD) simulations showed that BtMan2A galactomannan binding was stronger under acidic conditions (-8.4 kcal/mol) than in a neutral environment (-7.6 kcal/mol), and the galactomannan ligand was more unstable under neutral conditions than acidic conditions. Qualitative surface plasmon resonance (SPR) experimentally confirmed the reduced binding capacity of BtMan2A at pH 7. Finally, synergistic β-mannanase to β-mannosidase (BtMan2A or CmMan5A) ratios required for maximal galactomannan hydrolysis were determined. All CcManA to CmMan5A combinations were synergistic (â1.2-fold), while combinations of CcManA with BtMan2A (â1.0-fold) yielded no hydrolysis improvement. In conclusion, the low specific activity of BtMan2A towards long and galactose-containing oligomers and its non-catalytic galactomannan binding ability led to no synergy with the mannanase, making GH2 mannosidases ineffective for use in cocktails for mannan degradation.The National Research Foundation (NRF) of South Africa, Rhodes University and the University of Pretoria.http://www.elsevier.com/locate/csbjhj2023BiochemistryGeneticsMicrobiology and Plant Patholog
A note on the universality of the Hagedorn behavior of pp-wave strings
Following on from recent studies of string theory on a one-parameter family
of integrable deformations of proposed by Lunin and
Maldacena, we carry out a systematic analysis of the high temperature
properties of type IIB strings on the associated pp-wave geometries. In
particular, through the computation of the thermal partition function and free
energy we find that not only does the theory exhibit a Hagedorn transition in
both the and class of pp-waves, but that the Hagedorn
temperature is insensitive to the deformation suggesting an interesting
universality in the high temperature behaviour of the pp-wave string theory. We
comment also on the implications of this universality on the
confinement/deconfinement transition in the dual
Leigh-Strassler deformation of Yang-Mills theory.Comment: 25 pages; fixed minor typo; added reference
A Comparative Study of National Infrastructures for Digital (Open) Educational Resources in Higher Education
This paper reports on the first stage of an international comparative study for the project âDigital educational
architectures: Open learning resources in distributed learning infrastructuresâEduArcâ, funded by the German
Federal Ministry of Education and Research. This study reviews the situation of digital educational resources
(or (O)ER) framed within the digital transformation of ten different Higher Education (HE) systems (Australia,
Canada, China, Germany, Japan, South Africa, South Korea, Spain, Turkey and the United States). Following
a comparative case study approach, we investigated issues related to the existence of policies, quality
assurance mechanisms and measures for the promotion of change in supporting infrastructure development
for (O)ER at the national level in HE in the different countries. The results of this mainly documentary research
highlight differences and similarities, which are largely due to variations in these countriesâ political structure
organisation. The discussion and conclusion point at the importance of understanding each countryâs context
and culture, in order to understand the differences between them, as well as the challenges they face
A Comparative Study of National Infrastructures for Digital (Open) Educational Resources in Higher Education
This paper reports on the first stage of an international comparative study for the project âDigital educational architectures: Open learning resources in distributed learning infrastructuresâEduArcâ, funded by the German Federal Ministry of Education and Research. This study reviews the situation of digital educational resources (or (O)ER) framed within the digital transformation of ten different Higher Education (HE) systems (Australia, Canada, China, Germany, Japan, South Africa, South Korea, Spain, Turkey and the United States). Following a comparative case study approach, we investigated issues related to the existence of policies, quality assurance mechanisms and measures for the promotion of change in supporting infrastructure development for (O)ER at the national level in HE in the different countries. The results of this mainly documentary research highlight differences and similarities, which are largely due to variations in these countriesâ political structure organisation. The discussion and conclusion point at the importance of understanding each countryâs context and culture, in order to understand the differences between them, as well as the challenges they face
Matter, Literacy, and English Language Teaching in an Underprivileged School in Spain
This article analyzes the processes and findings of a collaborative action research (CAR) project that aimed to analyze the potential of materiality to radically transform the way English was taught and learned in an underprivileged public school in Spain. The CAR drew on new materialisms and new literacy studies to explore the relationship between matter and English language teaching from socioeconomic, sociocultural, and technological perspectives. The main pedagogical strategy consisted of widening the quantity and quality of the material resources in the English classroom, precisely to draw a material link between the English classroom and the students' homes, communities, and the informal literacies they enacted in them. Through two cycles of inquiry, the CAR team put into practice two multimodal and artifactual workshops with a group of nine children from underprivileged, minority backgrounds. A variety of qualitative strategies were used (including classroom recordings, student interviews, and photographs) to confirm that the insights from new materialisms and new literacy studies had generated opportunities for meaningful English learning within a culturally sustaining pedagogy
Ontological transparency, (in)visibility, and hidden curricula:Critical pedagogy and contentious edtech
AbstractThe steady migration of higher education online has accelerated in the wake of Covid-19. The implications of this migration on critical praxisâthe theory-in-practice of pedagogyâdeserve further scrutiny. This paper explores how teacher and student-led educational technology research and development can help rethink online critical praxis. The paper is based on a recent research project at the University of Edinburgh that speculatively explored the potential for automation in teaching, which generated insights into current and future pedagogical practice among both teachers and students. From this project emerged a series of pedagogical positions that were centred around visions of the future of teaching in response to automation: the pedagogical potential of visibility and invisibility online, transparency, and interrogating the hidden curricula of both higher education and educational technology itself. Through the surfacing of these pedagogical positions, this paper explores how critical pedagogy can be built into the broader teacher function and begins to identify the institutional structures that could potentially impede or accelerate that process.</jats:p
Popular pedagogy and the changing political landscape: a case study of a women's housing movement in South Africa
- âŚ