4,646 research outputs found
Relative sensitivity of two marine bivalves for detection of genotoxic and cytotoxic effects: a field assessment in the Tamar Estuary, South West England.
The input of anthropogenic contaminants to the aquatic environment is a major concern for scientists, regulators and the public. This is especially relevant in areas such as the Tamar valley in SW England, which has a legacy of contamination from industrial activity in the nineteenth and twentieth centuries. Following on from previous laboratory validation studies, this study aimed to assess the relationship between genotoxic and cytotoxic responses and heavy metal concentrations in two bivalve species sampled from locations along the Tamar estuary. Adult cockles, Cerastoderma edule, and blue mussels, Mytilus edulis, were sampled from five locations in the Tamar and one reference location on the south Devon coast. Bivalve haemocytes were processed for comet and neutral red retention (NRR) assays to determine potential genotoxic and cytotoxic effects, respectively. Sediment and soft tissue samples were analysed for metal content by inductively coupled plasma mass spectrometry. Sediment concentrations were consistent with the physico-chemical nature of the Tamar estuary. A significant correlation (P = 0.05) was found between total metal concentration in sediment and C. edule soft tissues, but no such correlation was found for M. edulis samples. DNA damage was elevated at the site with highest Cr concentrations for M. edulis and at the site with highest Ni and Pb concentrations for C. edule. Analysis of NRR revealed a slight increase in retention time at one site, in contrast to comet data. We conclude that the comet assay is a reliable indicator of genotoxic damage in the field for both M. edulis and C. edule and discuss reasons for the apparent discrepancy with NRR
Interfacial Tensions near Critical Endpoints: Experimental Checks of EdGF Theory
Predictions of the extended de Gennes-Fisher local-functional theory for the
universal scaling functions of interfacial tensions near critical endpoints are
compared with experimental data. Various observations of the binary mixture
isobutyric acid water are correlated to facilitate an analysis of the
experiments of Nagarajan, Webb and Widom who observed the vapor-liquid
interfacial tension as a function of {\it both} temperature and density.
Antonow's rule is confirmed and, with the aid of previously studied {\it
universal amplitude ratios}, the crucial analytic ``background'' contribution
to the surface tension near the endpoint is estimated. The residual singular
behavior thus uncovered is consistent with the theoretical scaling predictions
and confirms the expected lack of symmetry in . A searching test of
theory, however, demands more precise and extensive experiments; furthermore,
the analysis highlights, a previously noted but surprising, three-fold
discrepancy in the magnitude of the surface tension of isobutyric acid
water relative to other systems.Comment: 6 figure
Steel bridge members under variable amplitude, long life fatigue loading, Final report, September 1983,85p.
Granular Cell Tumor Occurring in the Chest Wall: A Case Report
Granular cell tumors are uncommon soft tissue neoplasm of nerve sheath origin, which are predominately benign. Granular cells can be found at any site in the body including the tongue, skin, subcutaneous tissue, breast, gastrointestinal, and urogenital systems. However, granular cell tumors have only been rarely described in the chest wall. Here we report a case of a granular cell tumor that occurred in the chest wall of a 59-year-old woman, along with a review of the literature
Cluster Variation Approach to the Random-Anisotropy Blume-Emery-Griffiths Model
The random--anisotropy Blume--Emery--Griffiths model, which has been proposed
to describe the critical behavior of He--He mixtures in a porous
medium, is studied in the pair approximation of the cluster variation method
extended to disordered systems. Several new features, with respect to mean
field theory, are found, including a rich ground state, a nonzero percolation
threshold, a reentrant coexistence curve and a miscibility gap on the high
He concentration side down to zero temperature. Furthermore, nearest
neighbor correlations are introduced in the random distribution of the
anisotropy, which are shown to be responsible for the raising of the critical
temperature with respect to the pure and uncorrelated random cases and
contribute to the detachment of the coexistence curve from the line.Comment: 14 pages (plain TeX) + 12 figures (PostScript, appended), Preprint
POLFIS-TH.02/9
Gender inequalities during COVID-19
This is the final version. Available on open access from SAGE Publications via the DOI in this record The onset of the global COVID-19 pandemic put a halt to progress toward gender equality and, instead, exacerbated existing gender inequalities across domains—from gendered divisions of labour to economic stability. In this paper we document some of the most glaring gender inequalities that have arisen in the COVID-19 pandemic and discuss how social psychological theories and research—including work on gender stereotypes and roles, responses to threat, precarious masculinity, perceptions of risk, and backlash—can help to explain the roots of these inequalities. In doing so, we use a broad definition of gender and consider relevant intersections of identity. Finally, we present three key considerations for research on gender inequalities moving forward. Namely, the need for social psychologists to (a) challenge binary conceptualizations of gender, (b) broaden the focus of research on gender inequalities, and (c) adopt an intersectional lens to address systemic inequalities in the wake of COVID-19.European Commissio
Treatment exhaustion of highly active antiretroviral therapy (HAART) among individuals infected with HIV in the United Kingdon: multicentre cohort study
Objectives:
To investigate whether there is evidence that an increasing proportion of HIV infected patients is starting to experience increases in viral load and decreases in CD4 cell count that are consistent with exhaustion of available treatment options.
Design:
Multicentre cohort study.
Setting:
Six large HIV treatment centres in southeast England.
Participants:
All individuals seen for care between 1 January 1996 and 31 December 2002.
Main outcome measures:
Exposure to individual antiretroviral drugs and drug classes, CD4 count, plasma HIV RNA burden.
Results:
Information is available on 16 593 individuals (13 378 (80.6%) male patients, 10 340 (62.3%) infected via homosexual or bisexual sex, 4426 (26.7%) infected via heterosexual sex, median age 34 years). Overall, 10 207 of the 16 593 patients (61.5%) have been exposed to any antiretroviral therapy. This proportion increased from 41.2% of patients under follow up at the end of 1996 to 71.3% of those under follow up in 2002. The median CD4 count and HIV RNA burden of patients under follow up in each year changed from 270 cells/mm3 and 4.34 log10 copies/ml in 1996 to 408 cells/mm3 and 1.89 log10 copies/ml, respectively, in 2002. By 2002, 3060 (38%) of patients who had ever been treated with antiretroviral therapy had experienced all three main classes. Of these, around one quarter had evidence of “viral load failure” with all these three classes. Patients with three class failure were more likely to have an HIV RNA burden > 2.7 log10 copies/ml and a CD4 count < 200 cells/mm3.
Conclusions:
The proportion of individuals with HIV infection in the United Kingdom who have been treated has increased gradually over time. A substantial proportion of these patients seem to be in danger of exhausting their options for antiretroviral treatment. New drugs with low toxicity, which are not associated with cross resistance to existing drugs, are urgently needed for such patients
Low temperature vortex liquid in
In the cuprates, the lightly-doped region is of major interest because
superconductivity, antiferromagnetism, and the pseudogap state
\cite{Timusk,Lee,Anderson} come together near a critical doping value .
These states are deeply influenced by phase fluctuations \cite{Emery} which
lead to a vortex-liquid state that surrounds the superconducting region
\cite{WangPRB01,WangPRB06}. However, many questions
\cite{Doniach,Fisher,FisherLee,Tesanovic,Sachdev} related to the nature of the
transition and vortex-liquid state at very low tempera- tures remain open
because the diamagnetic signal is difficult to resolve in this region. Here, we
report torque magnetometry results on (LSCO) which show
that superconductivity is lost at by quantum phase fluctuations. We find
that, in a magnetic field , the vortex solid-to-liquid transition occurs at
field much lower than the depairing field . The vortex liquid
exists in the large field interval , even in the limit 0.
The resulting phase diagram reveals the large fraction of the - plane
occupied by the quantum vortex liquid.Comment: 6 pages, 4 figures, submitted to Nature Physic
Career Barriers and Motivations for Women and Men Working in Disaster Risk Reduction: A Snapshot in the Asia-Pacific Region
This is the final version. Available on open access from the United Nations Office for Disaster Risk Reduction via the DOI in this recordThis publication explores enablers and barriers to women’s careers and leadership aspirations in disaster risk reduction (DRR), the ways in which workplace outcomes are different for women and men, the understanding of what predicts these differential outcomes and what opportunities there are to redress them.
The results of this research suggest the day-to-day experiences of DRR professionals shape their career motivations and ambition, their well-being and their desire to stay within the profession. While there are many commonalities in women and men’s experiences in DRR, there are also key differences. The report identified barriers to women’s career advancement, well-being and longevity in DRR including but not limited to: women’s lower willingness to sacrifice for their careers (likely influenced by lower expectations that these sacrifices will be rewarded), care demands placed on women with children, organisational constraints on women’s workplace authenticity, lower work-life balance and lower quality professional relationships with co-workers and especially senior colleagues. The study also uncovered barriers to men’s well-being in DRR, particularly in regard to their experiences of bullying, burnout and desire to leave the profession. Importantly, the findings also offer insight into what organisations and the DRR profession more broadly can do to improve women and men’s career outcomes in DRR
Neisseria oralis sp. nov., isolated from healthy gingival plaque and clinical samples
A polyphasic analysis was undertaken of seven independent isolates of Gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbour, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the novel species belongs in the genus Neisseria. The predominant cellular fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω7c. The cellular fatty acid profile, together with other phenotypic characters, further supports the inclusion of the novel species in the genus Neisseria. The name Neisseria oralis sp. nov. (type strain 6332T = DSM 25276T = LMG 26725T) is proposed
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