319 research outputs found

    Dynamics of precipitation pattern formation at geothermal hot springs

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    We formulate and model the dynamics of spatial patterns arising during the precipitation of calcium carbonate from a supersaturated shallow water flow. The model describes the formation of travertine deposits at geothermal hot springs and rimstone dams of calcite in caves. We find explicit solutions for travertine domes at low flow rates, identify the linear instabilities which generate dam and pond formation on sloped substrates, and present simulations of statistical landscape evolution

    The determinants of vulnerability to currency crises: country-specific factors versus regional factors

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    We investigate the determinants of exchange market pressures (EMP) for some new EU member states at both the national and regional levels, where macroeconomic and financial variables are considered as potential sources. The regional common factors are extracted from these variables by using dynamic factor analysis. The linear empirical analysis, in general, highlights the importance of country-specific factors to defend themselves against vulnerability in their external sectors. Yet, given a significant impact of the common component in credit on EMP, a contagion effect is apparent through the conduit of credit market integration across these countries under investigation

    Impact of COVID-19 on carers of people with dementia

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    Objective Unpaid carers for people with dementia play a crucial role in society. Emerging evidence suggests the COVID-19 pandemic has negatively impacted on carers. This study sought to explore the impact of the COVID-19 pandemic on carers for community-dwelling people with dementia and compare responses with pre-pandemic data. Methods Data were collected between September 2020 and April 2021 in England and Wales. Carers were identified from the IDEAL cohort and data were collected either through the telephone, video conferencing, or an online questionnaire. Responses from 242 carers were compared against benchmark data from the IDEAL cohort collected pre-pandemic. Analyses were conducted for the full sample of carers and spousal/partner carers only. Results In total 48.8% of carers thought their healthcare needs were negatively affected during the pandemic. Compared with pre-pandemic data carers were more lonely and experienced less life satisfaction. There was little impact on carers’ experience of caregiving, although carers felt trapped in their caregiving role. Carers were more optimistic and had higher social contact with relatives. There were changes in the methods carers used for contacting relatives and friends. Most carers coped very or fairly well during the pandemic. There was little difference in the experiences of spousal/partner carers and the full sample. Conclusions After a long period of providing care under pandemic conditions carers require additional support. This support needs to be focused on alleviating feelings of loneliness and increasing life satisfaction. Services need to consider how to improve access to health care, particularly resuming face-to-face appointments.Economic and Social Research Council (ESRC) through grant ES/V004964/1 | National Institute for Health Research (NIHR) through grant ES/L001853/2 | Alzheimer’s Society, grant number 348, AS-PR2-16-00

    Placental syncytiotrophoblast constitutes a major barrier to vertical transmission of Listeria monocytogenes.

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    Listeria monocytogenes is an important cause of maternal-fetal infections and serves as a model organism to study these important but poorly understood events. L. monocytogenes can infect non-phagocytic cells by two means: direct invasion and cell-to-cell spread. The relative contribution of each method to placental infection is controversial, as is the anatomical site of invasion. Here, we report for the first time the use of first trimester placental organ cultures to quantitatively analyze L. monocytogenes infection of the human placenta. Contrary to previous reports, we found that the syncytiotrophoblast, which constitutes most of the placental surface and is bathed in maternal blood, was highly resistant to L. monocytogenes infection by either internalin-mediated invasion or cell-to-cell spread. Instead, extravillous cytotrophoblasts-which anchor the placenta in the decidua (uterine lining) and abundantly express E-cadherin-served as the primary portal of entry for L. monocytogenes from both extracellular and intracellular compartments. Subsequent bacterial dissemination to the villous stroma, where fetal capillaries are found, was hampered by further cellular and histological barriers. Our study suggests the placenta has evolved multiple mechanisms to resist pathogen infection, especially from maternal blood. These findings provide a novel explanation why almost all placental pathogens have intracellular life cycles: they may need maternal cells to reach the decidua and infect the placenta

    Impact of COVID-19 on ‘living well’ with mild-to-moderate dementia in the community: findings from the IDEAL cohort

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    Economic and Social Research Council (ESRC) grant ES/V004964/1; Economic and Social Research Council (ESRC) and National Institute for Health Research (NIHR) joint grant ES/L001853/2; Alzheimer’s Society, grant number 348, AS-PR2-16-001; NIHR Applied Research Collaboration South-West Peninsula

    Biologically induced mineralization of dypingite by cyanobacteria from an alkaline wetland near Atlin, British Columbia, Canada

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    Background: This study provides experimental evidence for biologically induced precipitation of magnesium carbonates, specifically dypingite (Mg(CO)(OH) ·5HO), by cyanobacteria from an alkaline wetland near Atlin, British Columbia. This wetland is part of a larger hydromagnesite (Mg(CO)(OH) ·4HO) playa. Abiotic and biotic processes for magnesium carbonate precipitation in this environment are compared. Results: Field observations show that evaporation of wetland water produces carbonate films of nesquehonite (MgCO ·3HO) on the water surface and crusts on exposed surfaces. In contrast, benthic microbial mats possessing filamentous cyanobacteria (Lyngbya sp.) contain platy dypingite (Mg (CO)4(OH)·5HO) and aragonite. Bulk carbonates in the benthic mats (δC avg. = 6.7%, δO avg. = 17.2%) were isotopically distinguishable from abiotically formed nesquehonite (δC avg. = 9.3%, δO avg. = 24.9%). Field and laboratory experiments, which emulated natural conditions, were conducted to provide insight into the processes for magnesium carbonate precipitation in this environment. Field microcosm experiments included an abiotic control and two microbial systems, one containing ambient wetland water and one amended with nutrients to simulate eutrophic conditions. The abiotic control developed an extensive crust of nesquehonite on its bottom surface during which [Mg] decreased by 16.7% relative to the starting concentration. In the microbial systems, precipitation occurred within the mats and was not simply due to the capturing of mineral grains settling out of the water column. Magnesium concentrations decreased by 22.2% and 38.7% in the microbial systems, respectively. Laboratory experiments using natural waters from the Atlin site produced rosettes and flakey globular aggregates of dypingite precipitated in association with filamentous cyanobacteria dominated biofilms cultured from the site, whereas the abiotic control again precipitated nesquehonite. Conclusion: Microbial mats in the Atlin wetland create ideal conditions for biologically induced precipitation of dypingite and have presumably played a significant role in the development of this natural Mg-carbonate playa. This biogeochemical process represents an important link between the biosphere and the inorganic carbon pool

    Minimal Impact of COVID-19 Pandemic on the Mental Health and Wellbeing of People Living With Dementia: Analysis of Matched Longitudinal Data From the IDEAL Study

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordData Availability Statement: The datasets presented in this article are not readily available because IDEAL data were deposited with the UK data archive in April 2020 and will be available to access from April 2023. Details of how the data can be accessed after that date can be found at: http://reshare.ukdataservice.ac.uk/854293/. INCLUDE data will be archived in connection with the IDEAL dataset in March 2022. Requests to access the datasets should be directed to http://reshare.ukdataservice.ac.uk/854293/ or Linda Clare [email protected]: Research suggests a decline in the mental health and wellbeing of people with dementia (PwD) during the COVID-19 pandemic; however few studies have compared data collected pre-pandemic and during the pandemic. Moreover, none have compared this change with what would be expected due to dementia progression. We explored whether PwD experienced changes in mental health and wellbeing by comparing pre-pandemic and pandemic data, and drew comparisons with another group of PwD questioned on two occasions prior to the pandemic. Methods: Community-dwelling PwD enrolled in the IDEAL programme were split into two groups matched for age group, sex, dementia diagnosis, and time since diagnosis. Although each group was assessed twice, one was assessed prior to and during the pandemic (pandemic group; n = 115) whereas the other was assessed prior to the pandemic (pre-pandemic group; n = 230). PwD completed measures of mood, sense of self, wellbeing, optimism, quality of life, and life satisfaction. Results: Compared to the pre-pandemic group, the pandemic group were less likely to report mood problems, or be pessimistic, but more likely to become dissatisfied with their lives. There were no changes in continuity in sense of self, wellbeing, and quality of life. Discussion: Results suggest the pandemic had little effect on the mental health and wellbeing of PwD, with any changes observed likely to be consistent with expected rates of decline due to dementia. Although personal accounts attest to the challenges experienced, PwD appear to have been resilient to the impact of lockdown and social restrictions during the pandemic.Economic and Social Research Council (ESRC)National Institute for Health Research (NIHR)Alzheimer’s Societ

    A Comparison of Well-Being of Carers of People with Dementia and Their Ability to Manage Before and During the COVID-19 Pandemic: Findings from the IDEAL Study

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    Data Access: IDEAL data were deposited with the UK data archive in April 2020 and will be available to access from April 2023. Details of how the data can be accessed after that date can be found here: https://reshare.ukdataservice.ac.uk/854293/ INCLUDE data will be deposited with the UK data archive in June 2022 and will be available to access from June 2023.IDEAL study...TB

    PLD1 is overexpressed in an ER-negative MCF-7 cell line variant and a subset of phospho-Akt-negative breast carcinomas

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    We have used a novel variant of the human oestrogen receptor (ER)-positive MCF-7 cell line, TMX2-28, as a model to study breast cancer. TMX2-28 cells show no detectable levels of mRNA or protein expression for the ER and express basal cytokeratins (CKs) 5, 14, and 17. cDNA microarray comparison between TMX2-28 and its parent cell line, MCF-7, identified 1402 differentially expressed transcripts, one of which was, phospholipase D1 (PLD1). Using real-time RT–PCR, we confirmed that PLD1 mRNA levels are 10-fold higher in TMX2-28 cells than in MCF-7 cells. We next examined PLD1 expression in human breast carcinomas. Phospholipase D1 mRNA levels were higher in breast tumours that expressed high-mRNA levels of basal CKs 5 and/or 17, but PLD1 mRNA levels were not significantly higher in ER-negative tumours. Phospholipase D1 protein was overexpressed in 10 of 42 (24%) breast tumours examined by IHC. Phospholipase D1 was overexpressed in 6 of 31 ER-positive tumours and 4 of 11 ER-negative tumours. Phospholipase D1 was overexpressed in three of the four tumours that showed high CK5/17 expression. Five PLD1-positive tumours were negative for phospho-Akt expression, but positive for phospho-mammalian target of rapamycin (mTOR) expression. The other five PLD1-positive breast tumours showed positive expression for phospho-Akt; however, only two of these cases were positive for phospho-mTOR. In this study, we report that PLD1 and phospho-mTOR are coexpressed in a subset of phospho-Akt-negative breast carcinomas
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