111 research outputs found
A model for the effects of germanium on silica biomineralization in choanoflagellates.
Silica biomineralization is a widespread phenomenon of major biotechnological interest. Modifying biosilica with substances like germanium (Ge) can confer useful new properties, although exposure to high levels of Ge disrupts normal biosilicification. No clear mechanism explains why this disruption occurs. Here, we study the effect of Ge on loricate choanoflagellates, a group of protists that construct a species-specific extracellular lorica from multiple siliceous costal strips. High Ge exposures were toxic, whereas lower Ge exposures produced cells with incomplete or absent loricae. These effects can be ameliorated by restoring the germanium : silicon ratio, as observed in other biosilicifying organisms. We developed simulations of how Ge interacts with polymerizing silica. In our models, Ge is readily incorporated at the ends of silica forming from silicic acid condensation, but this prevents further silica polymerization. Our 'Ge-capping' model is supported by observations from loricate choanoflagellates. Ge exposure terminates costal strip synthesis and lorica formation, resulting in disruption to cytokinesis and fatal build-up of silicic acid. Applying the Ge-capping model to other siliceous organisms explains the general toxicity of Ge and identifies potential protective responses in metalloid uptake and sensing. This can improve the design of new silica biomaterials, and further our understanding of silicon metabolism.Higher Education Funding Council for England (Strategic Research Infrastructure Funding), Science and Technology Facilities Council, European Research Council (Advanced Investigator Grant ID: 247333), Wellcome Trust (Senior Investigator Award), Medical Research Council (Grant ID: U105960399, MRC-HNR Career Development Fellowship), European Research Council (Starting Grant ID: 282101 under the European Unionâs Seventh Framework Programme (FP7/2007-2013))This is the final version of the article. It first appeared from Royal Society Publishing via http://dx.doi.org/10.1098/rsif.2016.048
Use of Mobile Telemedicine for Cervical Cancer Screening
Visual inspection of the cervix with application of 4% acetic acid (VIA) is an inexpensive alternative to cytology-based screening in areas where resources are limited, such as in many developing countries. We have examined the diagnostic agreement between off-site (remote) expert diagnosis using photographs of the cervix (photographic inspection with acetic acid, PIA) and in-person VIA. The images for remote evaluation were taken with a mobile phone and transmitted by MMS. The study population consisted of 95 HIV-positive women in Gaborone, Botswana. An expert gynaecologist made a definitive positive or negative reading on the PIA results of 64 out of the 95 women whose PIA images were also read by the nurse midwives. The remaining 31 PIA images were deemed insufficient in quality for a reading by the expert gynaecologist. The positive nurse PIA readings were concordant with the positive expert PIA readings in 82% of cases, and the negative PIA readings between the two groups were fully concordant in 89% of cases. These results suggest that mobile telemedicine may be useful to improve access of women in remote areas to cervical cancer screening utilizing the VIA `see-andtreat\u27 method
Double jeopardy: the influence of excessive daytime sleepiness and impaired cognition on healthârelated quality of life in adults with heart failure
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106066/1/ejhfhfs054.pd
Future teleworking inclinations post-COVID-19: examining the role of teleworking conditions and perceived productivity
Organisations have implemented intensive home-based teleworking in response to global COVID-19 lockdowns and other pandemic-related restrictions. Financial pressures are driving organisations to continue intensive teleworking after the pandemic. Understanding employeesâ teleworking inclinations post COVID-19, and how these inclinations are influenced by different factors, is important to ensure any future, more permanent changes to teleworking policies are sustainable for both employees and organisations. This study, therefore, investigated the relationships between the context of home-based teleworking during the pandemic (pandemic-teleworking conditions), productivity perceptions during home-based teleworking, and employeesâ future teleworking inclinations (FTI) beyond the pandemic. Specifically, the study examined whether pandemic-teleworking conditions related to the job, and the physical and social environments at home, influenced employeesâ FTI, and if perceptions of improved or reduced productivity mediated these relationships. Data were collected during April and May 2020 with a cross-sectional online survey of teleworkers (n = 184) in Germany, Switzerland, the United Kingdom, and other countries during the first COVID-19 lockdowns. Reported FTI were mixed. Most participants (61%) reported wanting to telework more post-pandemic compared to before the pandemic; however, 18% wanted to telework less. Hierarchical multiple regression analysis revealed that some teleworking conditions (job demands and work privacy fit) were positively associated with FTI. Other teleworking conditions (specifically, job change, job control, home office adequacy, and childcare) were not associated with FTI. Perceived changes in productivity mediated the relationship between work privacy fit and FTI. Findings highlight the role of work privacy fit and job demands in influencing pandemic productivity perceptions and teleworking inclinations post-pandemic. Results raise questions about the suitability and sustainability of home-based teleworking for all staff. As organisations plan to increase the proportion of teleworking post-pandemic, this study suggests there is a need to support employees who perceived their productivity to be poor while home-working during the pandemic
Labour market experiences of young UK Bangladeshi men: Identity, inclusion and exclusion in inner-city London
Detailed qualitative data are used to explore the processes perpetuatinglabour market disadvantage among young UK-Bangladeshi men living in central London. Strong forces of inclusion within the Bangladeshi community are found to interact with forces of exclusion from âmainstreamâ
society to constrain aspirations and limit opportunities. Though diverse forms of young Bangladeshi masculinity are found, a common pattern is heavy dependency on intra-ethnic networks. Negative experiences of and isolation from âmainstreamâ society further reinforce reliance
on âour own peopleâ. However, acute ambivalence towards belonging to a dense Bangladeshi community exists, exemplified in the widespread denigration of the restaurant trade. Many respondents express the desire to âbreak outâ and access new experiences. The findings support current
policy emphasis on âconnecting people to workâ but highlight the more fundamental need to connect people across ethnic boundaries. The paper urges researchers to âunpackâ ethnicity to consider carefully what ethnic
identity implies in terms of access to resources and opportunities for different individuals in different contexts in order better to understand the diversity of labour market outcomes and the persistence of disadvantage
Optimal translational termination requires C4 lysyl hydroxylation of eRF1
Efficient stop codon recognition and peptidyl-tRNA hydrolysis are essential in order to terminate translational elongation and maintain protein sequence fidelity. Eukaryotic translational termination is mediated by a release factor complex that includes eukaryotic release factor 1 (eRF1) and eRF3. The N terminus of eRF1 contains highly conserved sequence motifs that couple stop codon recognition at the ribosomal A site to peptidyl-tRNA hydrolysis. We reveal that Jumonji domain-containing 4 (Jmjd4), a 2-oxoglutarate- and Fe(II)-dependent oxygenase, catalyzes carbon 4 (C4) lysyl hydroxylation of eRF1. This posttranslational modification takes place at an invariant lysine within the eRF1 NIKS motif and is required for optimal translational termination efficiency. These findings further highlight the role of 2-oxoglutarate/Fe(II) oxygenases in fundamental cellular processes and provide additional evidence that ensuring fidelity of protein translation is a major role of hydroxylation
IL-13 is a driver of COVID-19 severity
Immune dysregulation is characteristic of the more severe stages of SARS-CoV-2 infection. Understanding the mechanisms by which the immune system contributes to COVID-19 severity may open new avenues to treatment. Here, we report that elevated IL-13 was associated with the need for mechanical ventilation in 2 independent patient cohorts. In addition, patients who acquired COVID-19 while prescribed Dupilumab, a mAb that blocks IL-13 and IL-4 signaling, had less severe disease. In SARS-CoV-2âinfected mice, IL-13 neutralization reduced death and disease severity without affecting viral load, demonstrating an immunopathogenic role for this cytokine. Following antiâIL-13 treatment in infected mice, hyaluronan synthase 1 (Has1) was the most downregulated gene, and accumulation of the hyaluronan (HA) polysaccharide was decreased in the lung. In patients with COVID-19, HA was increased in the lungs and plasma. Blockade of the HA receptor, CD44, reduced mortality in infected mice, supporting the importance of HA as a pathogenic mediator. Finally, HA was directly induced in the lungs of mice by administration of IL-13, indicating a new role for IL-13 in lung disease. Understanding the role of IL-13 and HA has important implications for therapy of COVID-19 and, potentially, other pulmonary diseases. IL-13 levels were elevated in patients with severe COVID-19. In a mouse model of the disease, IL-13 neutralization reduced the disease and decreased lung HA deposition. Administration of IL-13âinduced HA in the lung. Blockade of the HA receptor CD44 prevented mortality, highlighting a potentially novel mechanism for IL-13âmediated HA synthesis in pulmonary pathology
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Passive immunization of macaques with polyclonal anti-SHIV IgG against a heterologous tier 2 SHIV: outcome depends on IgG dose
Background: A key goal for HIV-1 envelope immunogen design is the induction of cross-reactive neutralizing antibodies (nAbs). As AIDS vaccine recipients will not be exposed to strains exactly matching any immunogens due to multiple HIV-1 quasispecies circulating in the human population worldwide, heterologous SHIV challenges are essential for realistic vaccine efficacy testing in primates. We assessed whether polyclonal IgG, isolated from rhesus monkeys (RMs) with high-titer nAbs (termed SHIVIG), could protect RMs against the R5-tropic tier-2 SHIV-2873Nip, which was heterologous to the viruses or HIV-1 envelopes that had elicited SHIVIG. Results: SHIVIG demonstrated binding to HIV Gag, Tat, and Env of different clades and competed with the broadly neutralizing antibodies b12, VRC01, 4E10, and 17b. SHIVIG neutralized tier 1 and tier 2 viruses, including SHIV-2873Nip. NK-cell depletion decreased the neutralizing activity of SHIVIG 20-fold in PBMC assays. Although SHIVIG neutralized SHIV-2873Nip in vitro, this polyclonal IgG preparation failed to prevent acquisition after repeated intrarectal low-dose virus challenges, but at a dose of 400 mg/kg, it significantly lowered peak viremia (P = 0.001). Unexpectedly, single-genome analysis revealed a higher number of transmitted variants at the low dose of 25 mg/kg, implying increased acquisition at low SHIVIG levels. In vitro, SHIVIG demonstrated complement-mediated Ab-dependent enhancement of infection (Câ-ADE) at concentrations similar to those observed in plasmas of RMs treated with 25 mg/kg of SHIVIG. Conclusion: Our primate model data suggest a dual role for polyclonal anti-HIV-1 Abs depending on plasma levels upon virus encounter
Using Routinely Collected Administrative Data in Public Health Research: Geocoding Alcohol Outlet Data
We describe our process of geocoding alcohol outlets to create a national longitudinal exposure dataset for Wales, United Kingdom from 2006 to 2011. We investigated variation in the availability of data items and the quality of alcohol outlet addresses held within unitary authorities. We used a standard geocoding method augmented with a manual matching procedure to achieve a fully spatially referenced dataset. We found higher quality addresses are held for outlets based in urban areas, resulting in the automatic geocoding of 68 % of urban outlets, compared to 48 % in rural areas. Missing postcodes and a lack of address structure contributed to a lower geocoding proportion. An urban rural bias was removed with the development of a manual matching procedure. Only one-half of the unitary authorities provided data on on/off sales and opening times, which are important availability factors. The resulting outlet dataset is suitable for contributing to the evidence-base of alcohol availability and alcohol-related harm. Local government should be encouraged to use standardised data fields, including addresses, to enable accurate geocoding of alcohol outlets and facilitate research that aims to prevent alcohol-related harm. Standardising data collection would enable efficient secondary data reuse using record linkage techniques, allowing the retrospective creation and evaluation of population-based natural experiments to provide evidence for policy and practice
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