2,511 research outputs found
Influence of Dilute Acetic Acid Treatments on American Pondweed Winter Buds in the Nevada Irrigation District, California
American pondweed (
Potamogeton nodosus
Poir.) is commonly
found in northern California irrigation canals. The
purpose of this study was to test the hypothesis that exposure
of American pondweed winter buds to dilute acetic acid under
field conditions would result in reduced subsequent biomass
Increased focal adhesion kinase- and urokinase-type plasminogen activator receptor-associated cell signaling in endothelial cells exposed to asbestos.
Exposure of low-passage endothelial cells in culture to nonlethal amounts of asbestos, but not refractory ceramic fiber-1, increases cell motility and gene expression. These changes may be initiated by the fibers mimicking matrix proteins as ligands for receptors on the cell surface. In the present study, 1- to 3-hr exposures of endothelial cells to 5 mg/cm2 of chrysotile asbestos caused marked cell elongation and motility. However, little morphological change was seen when chrysotile was added to cells pretreated with either mannosamine to prevent assembly of glycophosphatidylinositol (GPI)-anchored receptors or with herbimycin A to inhibit tyrosine kinase activity. Affinity purification of GPI-anchored urokinase-type plasminogen activator receptor (uPAR) from chrysotile-exposed cells demonstrated that asbestos altered the profile of proteins and phosphoproteins complexed with this receptor. Tyrosine kinase activities in the complexes were also increased by asbestos. Immunoprecipitations with selective monoclonal antibodies demonstrated that both chrysotile and crocidolite asbestos increase kinase activities associated with p60 Src or p120 focal adhesion kinase (FAK). Further, chrysotile also changed the profile of proteins and phosphoproteins associated with FAK in intact cells. These data suggest that asbestos initiates endothelial cell phenotypic change through interactions with uPAR-containing complexes and that this change is mediated through tyrosine kinase cascades
Southwest Pacific subtropics responded to last deglacial warming with changes in shallow water sources
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 29 (2014): 595â611, doi:10.1002/2013PA002584.This study examined sources of mixed layer and shallow subsurface waters in the subtropical Bay of Plenty, New Zealand, across the last deglaciation (~30â5âka). ÎŽ18O and ÎŽ13C from planktonic foraminifera Globgerinoides bulloides and Globorotalia inflata in four sediment cores were used to reconstruct surface mixed layer thickness, ÎŽ18O of seawater (ÎŽ18OSW) and differentiate between high- and low-latitude water provenance. During the last glaciation, depleted planktonic ÎŽ18OSW and enriched ÎŽ13C (â0.4â0.1â°) indicate surface waters had Southern Ocean sources. A rapid ÎŽ13C depletion of ~1â° in G. bulloides between 20 and 19âka indicates an early, permanent shift in source to a more distal tropical component, likely with an equatorial Pacific contribution that persisted into the Holocene. At 18âka, a smaller but similar shift in G. inflata ÎŽ13C depletion of ~0.3â° suggests that deeper subsurface waters had a delayed reaction to changing conditions during the deglaciation. This contrasts with the isotopic records from nearby Hawke Bay, to the east of the North Island of New Zealand, which exhibited several changes in thermocline depth indicating switches between distal subtropical and proximal subantarctic influences during the early deglaciation ending only after the Antarctic Cold Reversal. Our results identify the midlatitude subtropics, such as the area around the North Island of New Zealand, as a key region to decipher high- versus low-latitude influences in Southern Hemisphere shallow water masses.Funding for this project
came from NSF OCE-0823487 and
0823549-03.2014-12-1
Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis
The coherence effects induced by external photons coupled to matter waves
inside a Mach-Zehnder three-grating interferometer are analyzed. Alternatively
to atom-photon entanglement scenarios, the model considered here only relies on
the atomic wave function and the momentum shift induced in it by the photon
scattering events. A functional dependence is thus found between the
observables, namely the fringe visibility and the phase shift, and the
transversal momentum transfer distribution. A good quantitative agreement is
found when comparing the results obtained from our model with the experimental
data.Comment: 18 pages, 4 figure
Manipulation of graphene's dynamic ripples by local harmonic out-of-plane excitation
With use of carefully designed molecular dynamics simulations, we demonstrate
tuning of dynamic ripples in free-standing graphene by applying a local
out-of-plane sinusoidal excitation. Depending on the boundary conditions and
external modulation, we show control of the local dynamic morphology, including
flattening and stable rippling patterns. In addition to studying the dynamic
response of atomically thin layers to external time-varying excitation, our
results open intriguing possibilities for modulating their properties via local
dynamic morphology control
Neutron-proton interaction in rare-earth nuclei: Role of tensor force
We investigate the role of the tensor force in the description of doubly odd
deformed nuclei within the framework of the particle-rotor model. We study the
rare-earth nuclei 174Lu, 180Ta, 182Ta, and 188Re using a finite-range
interaction, with and without tensor terms. Attention is focused on the lowest
K=0 and K=1 bands, where the effects of the residual neutron-proton interaction
are particularly evident. Comparison of the calculated results with
experimental data evidences the importance of the tensor-force effects.Comment: 8 pages, 5 figures, to be published on Physical Review
Development of a high throughput, molecular diagnostic assay for predicting telomerase activity in breast cancer cell lines and tissues
Telomerase is a cellular enzyme that helps to provide genomic stability in tumor cells by maintaining the integrity of telomeres. Telomerase is an RNA-dependent DNA polymerase that contains a protein component (hTERT) and an associated RNA (hTR), which is used as a template for telomere repeat addition. Telomerase activity, while not detectable in most normal human somatic cells, is associated with approximately 85% of malignant human cancers overall, including over 90% of breast cancers.
We have optimized a novel, quantitative, high-throughput telomerase activity assay using fluorescently labelled primers and Real Time quantitation via the ABI Prism 7700 (a.k.a., the TaqMan). Using established breast cancer cell lines and a subset of breast tumors, we demonstrate that telomerase levels quantitated from the TaqMan-based assay closely correlate with values obtained using the traditional, gel-based telomerase activity assay (TRAP). In addition, we have assessed the levels of both hTERT mRNA and hTR in each of our samples via RT-PCR to determine whether relative amounts or a ratio of the two telomerase components correlate with activity in a given sample. Our ultimate goal is to develop a Real Time, fluorescent RT-PCR assay to simultaneously measure hTERT and hTR messages in breast tumor samples, in an attempt to convert the enzymatic telomerase activity assay into a quantitative nucleic acid test to predict levels of activity in routinely processed clinical specimens
Predicting seabed burial of cylinders by wave-induced scour : application to the sandy inner shelf off Florida and Massachusetts
Author Posting. © IEEE, 2007. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 32 (2007): 167-183, doi:10.1109/JOE.2007.890958.A simple parameterized model for wave-induced
burial of mine-like cylinders as a function of grain-size,
time-varying, wave orbital velocity and mine diameter was
implemented and assessed against results from inert instrumented
mines placed off the Indian Rocks Beach (IRB, FL), and off the
Marthaâs Vineyard Coastal Observatory (MVCO, Edgartown,
MA). The steady flow scour parameters provided by Whitehouse
(1998) for self-settling cylinders worked well for predicting burial
by depth below the ambient seabed for Î (0.5 m) diameter mines
in fine sand at both sites. By including or excluding scour pit
infilling, a range of percent burial by surface area was predicted
that was also consistent with observations. Rapid scour pit infilling
was often seen at MVCO but never at IRB, suggesting that the
environmental presence of fine sediment plays a key role in promoting
infilling. Overprediction of mine scour in coarse sand was
corrected by assuming a mine within a field of large ripples buries
only until it generates no more turbulence than that produced by
surrounding bedforms. The feasibility of using a regional wave
model to predict mine burial in both hindcast and real-time forecast
mode was tested using the National Oceanic and Atmospheric
Administration (NOAA, Washington, DC) WaveWatch 3 (WW3)
model. Hindcast waves were adequate for useful operational
forcing of mine burial predictions, but five-day wave forecasts
introduced large errors. This investigation was part of a larger
effort to develop simple yet reliable predictions of mine burial
suitable for addressing the operational needs of the U.S. Navy.This work was supported by the grants from the U.S. Office of
Naval Research Marine Geosciences Program. The work of A. C. Trembanis
was supported by the USGS/WHOI Postdoctoral Fellowship
Emergency ambulance service involvement with residential care homes in the support of older people with dementia : an observational study
© 2014 Amador et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Older people resident in care homes have a limited life expectancy and approximately two-thirds have limited mental capacity. Despite initiatives to reduce unplanned hospital admissions for this population, little is known about the involvement of emergency services in supporting residents in these settings.METHODS: This paper reports on a longitudinal study that tracked the involvement of emergency ambulance personnel in the support of older people with dementia, resident in care homes with no on-site nursing providing personal care only. 133 residents with dementia across 6 care homes in the East of England were tracked for a year. The paper examines the frequency and reasons for emergency ambulance call-outs, outcomes and factors associated with emergency ambulance service use. RESULTS: 56% of residents used ambulance services. Less than half (43%) of all call-outs resulted in an unscheduled admission to hospital. In addition to trauma following a following a fall in the home, results suggest that at least a reasonable proportion of ambulance contacts are for ambulatory care sensitive conditions. An emergency ambulance is not likely to be called for older rather than younger residents or for women more than men. Length of residence does not influence use of emergency ambulance services among older people with dementia. Contact with primary care services and admission route into the care home were both significantly associated with emergency ambulance service use. The odds of using emergency ambulance services for residents admitted from a relative's home were 90% lower than the odds of using emergency ambulance services for residents admitted from their own home. CONCLUSIONS: Emergency service involvement with this vulnerable population merits further examination. Future research on emergency ambulance service use by older people with dementia in care homes, should account for important contextual factors, namely, presence or absence of on-site nursing, GP involvement, and access to residents' family, alongside resident health characteristics.Peer reviewedFinal Published versio
Investigating the meaning of 'good' or 'very good' patient evaluations of care in English general practice: A mixed methods study
This is the final version. Available from the publisher via the DOI in this record.The data set is available on request from the
authors: please email Jenni Burt ( [email protected]) for details.Objective: To examine concordance between responses to patient experience survey items evaluating doctors' interpersonal skills, and subsequent patient interview accounts of their experiences of care. Design: Mixed methods study integrating data from patient questionnaires completed immediately after a video-recorded face-to-face consultation with a general practitioner (GP) and subsequent interviews with the same patients which included playback of the recording. Setting: 12 general practices in rural, urban and inner city locations in six areas in England. Participants: 50 patients (66% female, aged 19-96 years) consulting face-to-face with 32 participating GPs. Main outcome measures: Positive responses to interpersonal skills items in a postconsultation questionnaire ('good' and 'very good') were compared with experiences reported during subsequent video elicitation interview (categorised as positive, negative or neutral by independent clinical raters) when reviewing that aspect of care. Results: We extracted 230 textual statements from 50 interview transcripts which related to the evaluation of GPs' interpersonal skills. Raters classified 70.9% (n=163) of these statements as positive, 19.6% (n=45) neutral and 9.6% (n=22) negative. Comments made by individual patients during interviews did not always express the same sentiment as their responses to the questionnaire. Where questionnaire responses indicated that interpersonal skills were 'very good', 84.6% of interview statements concerning that item were classified as positive. However, where patients rated interpersonal skills as 'good', only 41.9% of interview statements were classified as positive, and 18.9% as negative. Conclusions: Positive responses on patient experience questionnaires can mask important negative experiences which patients describe in subsequent interviews. The interpretation of absolute patient experience scores in feedback and public reporting should be done with caution, and clinicians should not be complacent following receipt of 'good' feedback. Relative scores are more easily interpretable when used to compare the performance of providers.NHS Cambridgeshire and Peterborough CCGNational Institute for Health Researc
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