32151 research outputs found
Sort by
Dalit activists promote social change differently : challenges and opportunities of digital activism and social change in Indian society
Get PDFWhile the power of the internet is often assumed to be universally pervasive and inherently democratic, the unique challenges faced by disadvantaged groups in utilizing it within repressive socio-political contexts are less understood. We examine how Dalits, a historically marginalized group in India living under repressive conditions, engage in online political activism. Drawing upon semi-structured interviews with 20 Dalit activists (15 men and 5 women), we argue that online political activism enables Dalits to circumvent the constraints imposed by caste-biased traditional media. This empowerment and mobilization of the Dalit movement are achieved through identity consolidation, politicization, and the formation of strong solidarity networks. Using reflexive thematic analysis (Braun & Clarke, 2019), We developed three themes that explore Dalit activists’ strategic utilization of digital technology and the potential ways social identity processes unfold in a repressive environment. The first theme highlights the ways in which Dalit activists navigate their exclusion from the mainstream by using social media to emphasise their grievances, build pressure on authorities, and gain attention of the public. The second illustrates the strategies Dalit activists use to develop the social psychological resources needed for social change, through building online community and political solidarity. Finally, the third highlights Dalit activists' difficulties when interacting online, such as incurring state-sanctioned punitive actions, increasing hostility on digital media platforms, and costs to well-being. We discuss the implications of our study for understanding the political activism among marginalised groups and collective action under repressive contexts.Peer reviewe
Mixed-phase enabled high-rate copper niobate anodes for lithium-ion batteries
No full textFunding: The authors would like to acknowledge the funding through the Netherlands Organization for Scientific Research (NWO) under the NWA research programme ‘Research of Routes by Consortia (ORC)’: Next Generation Batteries based on Understanding Materials Interfaces' project (NWA.1389.20.089). J. W. G. Bos would like to acknowledge the Leverhulme Trust for an International Academic Fellowship award (IAF-2020-012). The authors thank the staff of the Balder beamline at the MAX IV synchrotron (Lund, Sweden) for support and access under proposal number 20230639.The advancement of rapid-response grid energy storage systems and the widespread adoption of electric vehicles are significantly hindered by the charging times and energy densities associated with current lithium-ion battery technology. In state-of-the-art lithium-ion batteries, graphite is employed as the standard negative electrode material. However, graphite suffers from polarization and deteriorating side-reactions at the high currents needed for fast charging. Transition metal-oxide anodes are attractive alternatives due to their enhanced power density. However, often these anodes make use of toxic or scarce elements, significantly limiting their future potential. In this work, we propose a new, facile solid-state synthesis method to obtain non-toxic, abundant, mixed-phase copper niobate (CuxNbyOz) anodes for lithium-ion batteries. The material consists of various phases working synergistically to deliver high electrochemical capacities at exceptional cycling rates (167 mA h g−1 at 1C, 95 mA h g−1 at 10C, 65 mA h g−1 at 60C and 37 mA h g−1 at 250C), large pseudocapacitive response (up to 90%), and high Li+ diffusion coefficient (1.8 × 10−12 cm2 s−1), at a stable capacity retention (99.98%) between cycles. Compared to graphite, at a comparable energy density (470 W h L−1), the composite material exhibits a 70 times higher power density (27 000 W L−1). These results provide a new perspective on the role of non-toxic and abundant elements for realizing ultrafast anode materials for future energy storage devices.Peer reviewe
Long-term interventions by conservation and development projects support successful recovery of tropical peatlands in Amazonia
Get PDFFunding: This work was supported by the NERC Knowledge Exchange Fellowships (grant no. NE/V018760/1 and NE/V018760/2); Gordon and Betty Moore Foundation (Grant #5439, MonANPeru network); Concytec/British Council/Embajada Británica Lima/Newton Fund (Grant ref. 220-2018); Concytec/NERC/Embajada Británica Lima/Newton Fund (Grant ref. 001-2019); and Wildlife Conservation Society. The research permit that included access to the protected area was granted by SERNANP (RJ-RNPS No. 028-2022-SERNANP-JEF).1. Rural communities in Amazonia rely on harvesting Mauritia flexuosa fruit, a dominant peatland palm, for their subsistence and income. However, these palms are felled to harvest the fruits, which has led to reduced resource availability due to the pressure exerted by the increasing fruit demand. As a result, climbing has been proposed as a means to harvest the fruits sustainably. However, the long-term ecological and socio-economic impacts of climbing, rather than felling, palms remain unknown. 2. We evaluate whether M. flexuosa populations and fruit production in managed peatland palm swamps have recovered within two rural communities in Peru where climbing to harvest palm fruits was adopted between 1999 and 2002. Since then, these communities have been supported by conservation and development projects. 3. We conducted interviews with community members to assess perceptions of change since the introduction of climbing and carried out forest inventories to estimate changes in two socio-economic indicators (volume of harvested M. flexuosa fruits and income) and three ecological indicators (pole stem density of M. flexuosa, seedling and sapling density, and the sex ratio of adult palms). 4. Our results reveal that the adoption of climbing has improved the health of the forest stands and incomes in both rural communities. Recovery of M. flexuosa populations was supported by local perceptions of increases in stand productivity, improved values of most indicators within managed stands compared to reference data from unmanaged stands in the region, and continuous recovery of degraded stands over time following the adoption of climbing by both communities. 5. Synthesis and applications. We demonstrate how long-term conservation and development initiatives can lead to successful outcomes for rural communities and peatland ecosystems. However, urgent adoption of sustainable harvesting techniques, such as the palm climbing in our study, is needed across Amazonia to safeguard the ecological integrity of peatlands, below carbon storage, and livelihoods. This transition will require long-term collaboration among different stakeholders, affordable management plans, and fair prices for sustainable management for peatland resources.Peer reviewe
Phenotypic and genotypic characterization of multidrug resistant and extended-spectrum β-lactamase-producing Enterobacterales isolated from clinical samples in the western region in Cameroon
Get PDFFunding: Raspail Carrel Founou received funding from the Mérieux Institute, Lyon France for the CAREFOOD project. CAREFOOD project had supported all the molecular aspect of this study. This work was also supported by the Research Institute of Centre of Expertise and Biological Diagnostic of Cameroon (CEDBCAM-RI).Background The 2017 World Health Organization (WHO) report has listed extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon. Methods A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value < 0.05 was considered statistically significant. Results A total of 152 Enterobacterales were isolated among 597 clinical samples including urine, blood, cervico-vaginal, urethral swabs and wound samples. The overall prevalence of ESBL-Enterobacterales was 29.61% (45/152). The most represented ESBL species were Escherichia coli (n = 23; 51.11%), Klebsiella pneumoniae (n = 8; 17.78%) and Citrobacter freundii (n = 6; 13.33%).Peer reviewe
Dynamics of many-body open quantum systems with structured environments
Get PDFIn condensed matter theory the many-body problem holds centre stage and in equilibrium a large number of techniques have been developed. These include path integration, mean-field theory and renormalisation group and have explained a wide variety of phenomena like phase transitions and transport effects such as superconductivity.
There are not nearly as many methods for out-of-equilibrium many-body systems as there are for equilibrium problems. There are a number of reasons for this. Analytically, there is no non-equilibrium analogue of the free energy which is minimised in equilibrium, rather, non-equilibrium steady states are determined dynamically. In terms of numerical approaches there are two main issues. One is the exponential scaling of the size of the Hilbert space making simulation of collective quantum particles intractable. The other is that one needs to derive the proper dissipation operators, which requires knowledge of the eigenstates. This is made even more important when the environment itself has a non-trivial density of states, said to be structured.
In this Thesis we use Redfield theory to derive microscopic dissipation processes in two prominent multi-particle models. Redfield theory gives a recipe for deriving the correct dissipative master equation from first principles by expressing the system-bath interaction in terms of the collective modes of the many-body system. First we study a model of two coupled bosonic particles and show that the true Rabi splitting deviates from the standard textbook formula. Instead we find a strong dependence on Lamb shifts, which are important in structured environ- ments. Then we study the dynamics of the driven transverse-field anisotropic XY model and investigate its non-equilibrium properties when structured dissipation is present. We discuss how structure can lead to heating or cooling depending on the detuning of the spectral peak of the density of states relative to the system eigenfrequencies
African women in science and development, bridging the gender gap
Get PDFScience and technology play a fundamental role in driving social progress and economic growth in today’s rapidly evolving world. Yet, despite considerable advancements, the gender gap in science remains a harsh reality, particularly for African women. This inequality directly impedes their invaluable perspectives and contributions to scientific advancements and innovations. Africa’s development requires significant investment in science, technology, engineering, and mathematics (STEM) fields and leadership. This opinion piece delves into the gender disparity prevailing in STEM, emphasizes the challenges that African women experience, highlights the immense potential that African women possess, and finally advocates for immediate efforts to bridge this gap.Peer reviewe
Increased SARS-CoV-2 IgG4 has variable consequences dependent upon Fc function, Fc receptor polymorphism, and viral variant
Get PDFFunding: this study is supported by the Medical Research Future Fund (MRFF) GNT #2016062 to J.A.J., J.A.T., T.H.N., K.K., A.K.W., S.J.K., and A.W.c. and an NHMRC investigator grant#2008093 to A.W.c. J.A.J. is supported by a Sylvia and Chatles Viertel Senior Medical Research Fellowships. W.S.l., J.A.J., t.h.n., K.K., A.K.W., and S.J.K. are also supported by NHMRC investigator grants.Repeated mRNA COVID-19 vaccination increases spike-specific immunoglobulin G4 (IgG4) titers. Here, we characterized the influence of increased IgG4 titers on a range of Fc-mediated responses. Elevated spike-specific IgG4 reduced binding to FcγRIIIa and decreased antibody-dependent cellular cytotoxicity. However, in individuals with lower total spike-specific IgG, IgG4 acted in synergy with other IgG subclasses to improve FcγRI and FcγRIIa binding and consequently antibody-dependent cellular phagocytosis. Furthermore, this trend was more pronounced with more recent SARS-CoV-2 variants where vaccination induced comparably lower total spike-specific titers. These observations were further confirmed by in silico modeling where antibody subclass concentrations and FcγR polymorphisms were modulated. Collectively, we illustrate that the impact of elevated IgG4 titers upon Fc functions is dependent on multiple interconnected antibody and antigen factors, which should be taken into consideration when dissecting the mechanisms driving an effective Fc-mediated response following vaccination.Peer reviewe
Expression profile of human cytomegalovirus UL111A cmvIL-10 and LAcmvIL-10 transcripts in primary cells and cells from renal transplant recipients
Get PDFFunding: This study was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil (FAPESP) (Grant number: 2020/08527-1) awarded to MCCS and by the UKRI MRC grant (grant Grant number: MR/Z504361/1) awarded to E.P.Human cytomegalovirus (HCMV) is a high-risk pathogen in immunocompromised individuals, especially in transplant recipients. HCMV viremia must be monitored, and frequently, patients are treated with antiviral agents. HCMV has a variety of strategies to modulate host antiviral responses, and one important player is a viral homolog of the cellular interleukin-10 (cIL-10). The viral UL111A gene produces several HCMV IL-10 transcripts and protein isoforms through alternative splicing. The cmvIL-10 (isoform A) has similar properties to cIL-10, while LAcmvIL-10 (isoform B) has more restricted biological properties. Other isoforms are produced (C to H) but have unknown functions. Here, we investigated the expression of the most abundant transcripts, cmvIL-10 and LAcmvIL-10, in productively and latently infected cells and in peripheral blood mononuclear cells from renal transplant recipients up to 60 days post-transplantation. This study investigated HCMV cmvIL-10 and LAcmvIL-10 transcription profiles in vitro, in productive and latent infection, and in vivo, in peripheral blood mononuclear cells (PBMCs) of renal transplant patients. In vitro, both cmvIL-10 and LAcmvIL-10 transcripts were detected in both types at high levels and low levels in MRC-5 and latent infected (CD14+). When PBMCs from transplant patients were analyzed, LAcmvIL-10 was detected mostly sporadically and in only a few patients, while cmvIL-10 was found in all patients at all time points. Furthermore, it was observed in PBMCs that expression of cmvIL-10 was positively associated with an increase in viral DNA detection in the subsequently collected sample, indicating that expression of cmvIL-10 might precede viral DNA replication. These results contribute to the understanding of HCMV biology in different phases of infection. In addition, our initial analysis suggests that monitoring cmvIL-10, along with viral DNA, could improve early detection of HCMV reactivation in transplant recipients.Peer reviewe
Genomic surveillance of invasive meningococcal disease during a national MenW outbreak in Australia, 2017-2018
Get PDFFunding: This work was supported by a National Health and Medical Research Council grant (APP1149991) and investigator grant to B. P. H. (APP1196103).Background. In Australia, invasive meningococcal disease (IMD) incidence rapidly increased between 2014 and 2017 due to rising serogroup W (MenW) and MenY infections. We aimed to better understand the genetic diversity of IMD during 2017 and 2018 using whole genome sequencing data. Methods. Whole genome sequencing data from 440 Australian IMD isolates collected during 2017 and 2018 and 1737 international MenW:CC11 isolates collected in Europe, Africa, Asia, North America, and South America between 1974 and 2020 were used in phylogenetic analyses; genetic relatedness was determined from single-nucleotide polymorphisms. Results. Australian isolates were as follows: 181 MenW (41%), 144 MenB (33%), 88 MenY (20%), 16 MenC (4%), 1 MenW/Y (0.2%), and 10 nongenogroupable (2%). Eighteen clonal complexes (CCs) were identified, and 3 (CC11, CC23, CC41/44) accounted for 78% of isolates (343/440). These CCs were associated with specific serogroups: CC11 (n = 199) predominated among MenW (n = 181) and MenC (n = 15), CC23 (n = 80) among MenY (n = 78), and CC41/44 (n = 64) among MenB (n = 64). MenB isolates were highly diverse, MenY were intermediately diverse, and MenW and MenC isolates demonstrated the least genetic diversity. Thirty serogroup and CC-specific genomic clusters were identified. International CC11 comparison revealed diversification of MenW in Australia. Conclusions. Whole genome sequencing comprehensively characterized Australian IMD isolates, indexed their genetic variability, provided increased within-CC resolution, and elucidated the evolution of CC11 in Australia.Peer reviewe
Competitive accretion and the baryonic fraction in galaxies
Get PDFThe baryonic fraction of galaxies is observed to vary with the mass of their dark matter (DM) halo. Low-mass galaxies have low baryonic fractions that increase to a maximum for masses near 1012 M☉, and decrease thereafter with increasing galaxy mass. This trend is generally attributed to the action of feedback from star formation at the low end and of active galactic nuclei at the high-mass end. An alternative is that the baryonic fraction is at least partially due to the ability of galaxies to competitively accrete gas in a group or clustered environment. Most galaxies in a group including those of lower masses orbit the cluster centre at significant speeds and hence their accretion is limited by a Bondi–Hoyle-type process, M˙acc ∝ MDM2. In contrast, the few high-mass galaxies reside in the core of the cluster and accrete in a tidal accretion process, M˙acc ∝ MDM2/3. These two mechanisms result in a baryonic mass fraction that increases as MDM at low masses and decreases as MDM-1/3 at high masses. This model predicts that lower mass haloes in small-N groups should have higher baryonic fractions relative to those in large clusters. Peer reviewe
Access Repository Dashboard
Do you manage St Andrews Research Repository? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!