831 research outputs found
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Viruses in nondisinfected drinking water from municipal wells and community incidence of acute gastrointestinal illness.
BackgroundGroundwater supplies for drinking water are frequently contaminated with low levels of human enteric virus genomes, yet evidence for waterborne disease transmission is lacking.ObjectivesWe related quantitative polymerase chain reaction (qPCR)-measured enteric viruses in the tap water of 14 Wisconsin communities supplied by nondisinfected groundwater to acute gastrointestinal illness (AGI) incidence.MethodsAGI incidence was estimated from health diaries completed weekly by households within each study community during four 12-week periods. Water samples were collected monthly from five to eight households per community. Viruses were measured by qPCR, and infectivity assessed by cell culture. AGI incidence was related to virus measures using Poisson regression with random effects.ResultsCommunities and time periods with the highest virus measures had correspondingly high AGI incidence. This association was particularly strong for norovirus genogroup I (NoV-GI) and between adult AGI and enteroviruses when echovirus serotypes predominated. At mean concentrations of 1 and 0.8 genomic copies/L of NoV-GI and enteroviruses, respectively, the AGI incidence rate ratios (i.e., relative risk) increased by 30%. Adenoviruses were common, but tap-water concentrations were low and not positively associated with AGI. The estimated fraction of AGI attributable to tap-water-borne viruses was between 6% and 22%, depending on the virus exposure-AGI incidence model selected, and could have been as high as 63% among children < 5 years of age during the period when NoV-GI was abundant in drinking water.ConclusionsThe majority of groundwater-source public water systems in the United States produce water without disinfection, and our findings suggest that populations served by such systems may be exposed to waterborne viruses and consequent health risks
Harmonising topographic & remotely sensed datasets, a reference dataset for shoreline and beach change analysis.
This paper presents a novel reference dataset for North Norfolk, UK, that demonstrates the value of harmonising coastal field-based topographic and remotely sensed datasets at local scales. It is hoped that this reference dataset and the associated methodologies will facilitate the use of topographic and remotely sensed coastal datasets, as demonstrated here using open-access UK Environment Agency datasets. Two core methodologies, used to generate the novel reference dataset, are presented. Firstly, we establish a robust approach to extracting shorelines from vertical aerial photography, validated against LiDAR (Light Detection and Ranging) and coastal topography surveys. Secondly, we present a standard methodology for quantifying sediment volume change from spatially continuous LiDAR elevation datasets. As coastal systems are monitored at greater spatial resolution and temporal frequency there is an unprecedented opportunity to determine how and why coastal systems have changed in the past with a view to informing future forecasting. With revelation of trends that suggest increasing coastal risk, coastal change research is needed to inform the management and protection of coasts
Gr\"obner Bases and Nullstellens\"atze for Graph-Coloring Ideals
We revisit a well-known family of polynomial ideals encoding the problem of
graph--colorability. Our paper describes how the inherent combinatorial
structure of the ideals implies several interesting algebraic properties.
Specifically, we provide lower bounds on the difficulty of computing Gr\"obner
bases and Nullstellensatz certificates for the coloring ideals of general
graphs. For chordal graphs, however, we explicitly describe a Gr\"obner basis
for the coloring ideal, and provide a polynomial-time algorithm.Comment: 16 page
New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope
We report on Hubble Space Telescope (HST) observations of three Kuiper Belt
Objects (KBOs), discovered in our dedicated ground-based search campaign, that
are candidates for long-range observations from the New Horizons spacecraft:
2011 JY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current
and future critical accuracy improvements for orbit precision, required for
possible New Horizons observations, beyond what can be obtained from the
ground. Photometric colors of all three objects are red, typical of the Cold
Classical dynamical population within which they reside; they are also the
faintest KBOs to have had their colors measured. None are observed to be binary
with HST above separations of ~0.02 arcsec (~700 km at 44 AU) and {\Delta}m
less than or equal to 0.5.Comment: Pages: 11, Figures: 2, Tables: 3, Icarus, available online May 2014
(http://dx.doi.org/10.1016/j.icarus.2014.04.014
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Associations between gut microbiota and immune markers in pediatric multiple sclerosis and controls
Will nature work with us? Erosion and flooding impacts on a UK barrier
‘Barrier island’ refers to a diverse collection of coastal landforms that often support substantial human populations, critical infrastructures, and ecosystems. Globally, many coastal barriers are experiencing climatically altered environmental forcing coupled with increasing anthropogenic pressures. This paper undertakes high resolution shoreline change analysis to reveal how Blakeney Point, a mixed sandy-gravel barrier located on the UK’s East Coast, has evolved over centennial, decadal and event timescales. We seek to establish the implications of barrier evolution, under contrasting management regimes, for present erosion and flooding hazards. Interrogating a series of alternative shoreline proxies reveals a series of interdependent behaviors. Over the 130-year period of study, Blakeney Point is shown to be rolling landward at a mean rate of 0.60 m a-1. Assuming continued landward retreat over the coming decades, future flood-generating storm events will encounter more landward shoreline positions than today. Superimposed on this trend, we observe the presence of alongshore migrating erosional hotspots which give rise to unpredictable morphologies at any given location on the spit. Finally, we find that instances of barrier setback are driven by individual storm events, which makes barrier retreat both highly variable and discontinuous in time and space. This is illustrated by the presence of overwash, particularly along stretches of the barrier that have experienced a recent shift in management regime towards a non-interventionist approach.This work was funded by the NERC/ESRC Data, Risk and Environmental Analytical Methods (DREAM) Centre, Grant/Award Number: NE/M009009/1. It is also a contribution to the NERC-funded project “Physical and Biological dynamic coastal processes and their role in coastal recovery” (BLUEcoast), Grant Award Number: NE/N015924/1
Cranberry and Grape Seed Extracts Inhibit the Proliferative Phenotype of Oral Squamous Cell Carcinomas
Proanthocyanidins, compounds highly concentrated in dietary fruits, such as cranberries and grapes, demonstrate significant cancer prevention potential against many types of cancer. The objective of this study was to evaluate cranberry and grape seed extracts to quantitate and compare their anti-proliferative effects on the most common type of oral cancer, oral squamous cell carcinoma. Using two well-characterized oral squamous cell carcinoma cell lines, CAL27 and SCC25, assays were performed to evaluate the effects of cranberry and grape seed extract on phenotypic behaviors of these oral cancers. The proliferation of both oral cancer cell lines was significantly inhibited by the administration of cranberry and grape seed extracts, in a dose-dependent manner. In addition, key regulators of apoptosis, caspase-2 and caspase-8, were concomitantly up-regulated by these treatments. However, cranberry and grape seed extracts elicited differential effects on cell adhesion, cell morphology, and cell cycle regulatory pathways. This study represents one of the first comparative investigations of cranberry and grape seed extracts and their anti-proliferative effects on oral cancers. Previous findings using purified proanthocyanidin from grape seed extract demonstrated more prominent growth inhibition, as well as apoptosis-inducing, properties on CAL27 cells. These observations provide evidence that cranberry and grape seed extracts not only inhibit oral cancer proliferation but also that the mechanism of this inhibition may function by triggering key apoptotic regulators in these cell lines. This information will be of benefit to researchers interested in elucidating which dietary components are central to mechanisms involved in the mediation of oral carcinogenesis and progression
Early-life adversity programs long-term cytokine and microglia expression within the HPA axis in female Japanese quail
This work was funded by the Biotechnology and Biological Sciences Research Council (BBSRC grant no. BB/L002264/1 to K.A.S., C.Z. and S.D.H.), a David Phillips Research Fellowship (K.A.S.) and an EASTBIO BBSRC Doctoral Training Programme studentship (grant no. BB/J01446X/1 to D.J.W., supervisors K.A.S., S.D.H.). Data are available from Mendeley (Walker, 2019): http://dx.doi.org/10.17632/ 6r7d2pg2zk.1Stress exposure during prenatal and postnatal development can have persistent and often dysfunctional effects on several physiological systems, including immune function, affecting the ability to combat infection. The neuroimmune response is inextricably linked to the action of the hypothalamic–pituitary–adrenal (HPA) axis. Cytokines released from neuroimmune cells, including microglia, activate the HPA axis, while glucocorticoids in turn regulate cytokine release from microglia. Because of the close links between these two physiological systems, coupled with potential for persistent changes to HPA axis activity following developmental stress, components of the neuroimmune system could be targets for developmental programming. However, little is known of any programming effects of developmental stress on neuroimmune function. We investigated whether developmental stress exposure via elevated prenatal corticosterone (CORT) or postnatal unpredictable food availability had long-term effects on pro- (IL-1β) and anti-inflammatory (IL-10) cytokine and microglia-dependent gene (CSF1R) expression within HPA axis tissues in a precocial bird, the Japanese quail (Coturnix japonica). Following postnatal stress, we observed increased IL-1β expression in the pituitary gland, reduced IL-10 expression in the amygdala and hypothalamus, and reduced CSF1R expression within the hypothalamus and pituitary gland. Postnatal stress disrupted the ratio of IL-1β:IL-10 expression within the hippocampus and hypothalamus. Prenatal stress only increased IL-1β expression in the pituitary gland. We found no evidence for interactive or cumulative effects across life stages on basal cytokine and glia expression in adulthood. We show that postnatal stress may have a larger impact than elevated prenatal CORT on basal immunity in HPA-axis-specific brain regions, with changes in cytokine homeostasis and microglia abundance. These results provide evidence for postnatal programming of a pro-inflammatory neuroimmune phenotype at the expense of reduced microglia, which could have implications for central nervous system health and subsequent neuroimmune responses.Publisher PDFPeer reviewe
Moored current meter, AVHRR, CTD, and drifter data from the Agulhas Current and Retroflexion region (1985-1987) Volume XLII
Stored in the Archives of the Woods Hole Oceanographic Institution is the floppy disk on which can be found the one-day average currents, the path of the Agulhas Current, CTD stations in "Live Atlas" format, SST frontal analyses (Chassignet and Olson, personal communcation) as well as
programs written in QuickBASIC which allow one to access and display these observations. The programs are stored in ASCII and
can be run under the Microsoft QuickBasic (Version 4.0 or higher). Instructions for running the programs can be found in a file
entitled "read.me" on the disk.Data are presented from an experiment designed to explore the spatial and temporal structure of the Agulhas Current and
Retroflexion by direct means. Included are the current meter results from 10 moorings in the Retroflexion region, CTD stations
occupied on the deployment cruise in 1985, data from satellite tracked (ARGOS) freely during surface buoys and numerous images
of the sea surface temperature.Funding was provided by the Office of Naval Research through Contract Nos.
NOOO14-84C-O134, NOO014-85-C-0001, and NOOO14-87-K-0007
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