1,766 research outputs found
The zebrafish xenograft platform-A novel tool for modeling KSHV-associated diseases
Kaposi\u27s sarcoma associated-herpesvirus (KSHV, also known as human herpesvirus-8) is a gammaherpesvirus that establishes life-long infection in human B lymphocytes. KSHV infection is typically asymptomatic, but immunosuppression can predispose KSHV-infected individuals to primary effusion lymphoma (PEL); a malignancy driven by aberrant proliferation of latently infected B lymphocytes, and supported by pro-inflammatory cytokines and angiogenic factors produced by cells that succumb to lytic viral replication. Here, we report the development of the firs
Development of a low-maintenance measurement approach to continuously estimate methane emissions: a case study
The chemical breakdown of organic matter in landfills represents a significant source of methane gas (CH4). Current estimates suggest that landfills are responsible for between 3% and 19% of global anthropogenic emissions. The net CH4 emissions resulting from biogeochemical processes and their modulation by microbes in landfills are poorly constrained by imprecise knowledge of environmental constraints. The uncertainty in absolute CH4 emissions from landfills is therefore considerable. This study investigates a new method to estimate the temporal variability of CH4 emissions using meteorological and CH4 concentration measurements downwind of a landfill site in Suffolk, UK from July to September 2014, taking advantage of the statistics that such a measurement approach offers versus shorter-term, but more complex and instantaneously accurate, flux snapshots. Methane emissions were calculated from CH4 concentrations measured 700 m from the perimeter of the landfill with observed concentrations ranging from background to 46.4 ppm. Using an atmospheric dispersion model, we estimate a mean emission flux of 709 μg m−2 s−1 over this period, with a maximum value of 6.21 mg m−2 s−1, reflecting the wide natural variability in biogeochemical and other environmental controls on net site emission. The emissions calculated suggest that meteorological conditions have an influence on the magnitude of CH4 emissions. We also investigate the factors responsible for the large variability observed in the estimated CH4 emissions, and suggest that the largest component arises from uncertainty in the spatial distribution of CH4 emissions within the landfill area. The results determined using the low-maintenance approach discussed in this paper suggest that a network of cheaper, less precise CH4 sensors could be used to measure a continuous CH4 emission time series from a landfill site, something that is not practical using far-field approaches such as tracer release methods. Even though there are limitations to the approach described here, this easy, low-maintenance, low-cost method could be used by landfill operators to estimate time-averaged CH4 emissions and their impact downwind by simultaneously monitoring plume advection and CH4 concentrations
Nursing students doing gender: Implications for higher education and the nursing profession
The average age of women nursing students in Australia is rising. With this comes the likelihood that more now begin university with family responsibilities, and with their lives structured by the roles of mother and partner. Women with more traditionally gendered ideas of these roles, such as nurturing others and self-sacrifice, are known to be attracted to nursing as a profession; once at university, however, these students can be vulnerable to gender role stress from the competing demands of study. A qualitative research design, guided by Gadamer\u27s hermeneutic philosophy, explored the gendered behaviours and experiences of 22 women nursing students, all of whom had children and began university in a heterosexual intimate relationship. The findings reveal traditional ideas of gender were almost universal among participants, and these ideas had a significant influence on the nursing degree experience. Participants commonly prioritised family over the university and practiced maternal gatekeeping (prevention of male partner involvement in domestic work). These traditionally gendered behaviours, coupled with experiences of gender role stress, had a detrimental impact on participants\u27 capacity to study and their personal wellbeing. The importance of these findings to the burgeoning nursing workforce shortage nursing is considered in terms of student retention and the supply of graduates into the profession. The implications to the nursing profession are also explored against the evidence that nursing students with traditional gender beliefs are less likely to develop as autonomous, critical thinking nurses compared to their gender-egalitarian peers. The introduction of gender theory via critical pedagogy in the undergraduate nursing degree curriculum is recommended to enlighten and empower women nursing students and promote the competence, agility, and sustainability of the nursing profession
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Correlation between biomarkers of exposure, effect and potential harm in the urine of electronic cigarette users.
ObjectivesTo determine if urinary biomarkers of effect and potential harm are elevated in electronic cigarette users compared with non-smokers and if elevation correlates with increased concentrations of metals in urine.Study design and settingThis was a cross-sectional study of biomarkers of exposure, effect and potential harm in urine from non-smokers (n=20), electronic cigarette users (n=20) and cigarette smokers (n=13). Participant's screening and urine collection were performed at the Roswell Park Comprehensive Cancer Center, and biomarker analysis and metal analysis were performed at the University of California, Riverside.ResultsMetallothionein was significantly elevated in the electronic cigarette group (3761±3932 pg/mg) compared with the non-smokers (1129±1294 pg/mg, p=0.05). 8-OHdG (8-hydroxy-2'-deoxyguanosine) was significantly elevated in electronic cigarette users (442.8±300.7 ng/mg) versus non-smokers (221.6±157.8 ng/mg, p=0.01). 8-Isoprostane showed a significant increase in electronic cigarette users (750.8±433 pg/mg) versus non-smokers (411.2±287.4 pg/mg, p=0.03). Linear regression analysis in the electronic cigarette group showed a significant correlation between cotinine and total metal concentration; total metal concentration and metallothionein; cotinine and oxidative DNA damage; and total metal concentration and oxidative DNA damage. Zinc was significantly elevated in the electronic cigarette users (584.5±826.6 µg/g) compared with non-smokers (413.6±233.7 µg/g, p=0.03). Linear regression analysis showed a significant correlation between urinary zinc concentration and 8-OHdG in the electronic cigarette users.ConclusionsThis study is the first to investigate biomarkers of potential harm and effect in electronic cigarette users and to show a linkage to metal exposure. The biomarker levels in electronic cigarette users were similar to (and not lower than) cigarette smokers. In electronic cigarette users, there was a link to elevated total metal exposure and oxidative DNA damage. Specifically, our results demonstrate that zinc concentration was correlated to oxidative DNA damage
A Bestiary of Higher Dimensional Taub-NUT-AdS Spacetimes
We present a menagerie of solutions to the vacuum Einstein equations in six,
eight and ten dimensions. These solutions describe spacetimes which are either
locally asymptotically adS or locally asymptotically flat, and which have
non-trivial topology. We discuss the global structure of these solutions, and
their relevance within the context of M-theory.Comment: 11 pages, LaTex(v4: Comments and references added
Finding the Needles in the Haystacks: High-Fidelity Models of the Modern and Archean Solar System for Simulating Exoplanet Observations
We present two state-of-the-art models of the solar system, one corresponding
to the present day and one to the Archean Eon 3.5 billion years ago. Each model
contains spatial and spectral information for the star, the planets, and the
interplanetary dust, extending to 50 AU from the sun and covering the
wavelength range 0.3 to 2.5 micron. In addition, we created a spectral image
cube representative of the astronomical backgrounds that will be seen behind
deep observations of extrasolar planetary systems, including galaxies and Milky
Way stars. These models are intended as inputs to high-fidelity simulations of
direct observations of exoplanetary systems using telescopes equipped with
high-contrast capability. They will help improve the realism of observation and
instrument parameters that are required inputs to statistical observatory yield
calculations, as well as guide development of post-processing algorithms for
telescopes capable of directly imaging Earth-like planets.Comment: Accepted for publication in PAS
Developmental Differences in Filtering Auditory and Visual Distractors During Visual Selective Attention
The current experiment examined changes in visual selective attention in young children, older children, young adults, and older adults while participants were instructed to ignore auditory and visual distractors. The aims of the study were to: (a) determine if the Perceptual Load Hypothesis (PLH) (distraction greater under low perceptual load) could predict which irrelevant stimuli would disrupt visual selective attention, and (b) if auditory to visual shifts found in modality dominance research could be extended to selective attention tasks. Overall, distractibility decreased with age, with incompatible distractors having larger costs in young and older children than adults. In regard to accuracy, visual distractibility did not differ across age nor load, whereas, auditory interference was more pronounced early in development and correlated with age. Auditory and visual distractors also slowed down responses in young and older children more than adults. Finally, the PLH did not predict performance. Rather, children often showed the opposite pattern, with visual distractors having a greater cost in the high load condition (older children) and auditory distractors having a greater cost in the high load condition (young children). These findings are consistent with research examining the development of modality dominance and shed light on changes in multisensory processing and selective attention across the lifespan
Assessing exhibition swine as potential disseminators of infectious disease through the detection of five respiratory pathogens at agricultural exhibitions
International audienceAbstractWidespread geographic movement and extensive comingling of exhibition swine facilitates the spread and transmission of infectious pathogens. Nasal samples were collected from 2862 pigs at 102 exhibitions and tested for five pathogens. At least one pathogen was molecularly detected in pigs at 63 (61.8%) exhibitions. Influenza A virus was most prevalent and was detected in 498 (17.4%) samples. Influenza D virus was detected in two (0.07%) samples. More than one pathogen was detected in 165 (5.8%) samples. Influenza A virus remains a top threat to animal and human health, but other pathogens may be disseminated through the exhibition swine population
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