4,428 research outputs found
Correction: Emotional impact of screening: A systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>There is a widely held expectation that screening for disease has adverse emotional impacts. The aim of the current review is to estimate the short (< 4 weeks) and longer term (> 4 weeks) emotional impact of such screening.</p> <p>Methods</p> <p>Studies selected for inclusion were (a) randomised controlled trials in which (b) participants in one arm underwent screening and received test results, and those in a control arm did not, and (c) emotional outcomes were assessed in both arms. MEDLINE via PubMed (1950 to present), EMBASE (1980 to present), PsycINFO (1985 to present) using OVID SP, and CINAHL (1982 to present) via EBSCO were searched, using strategies developed with keywords and medical subject headings. Data were extracted on emotional outcomes, type of screening test and test results.</p> <p>Results</p> <p>Of the 12 studies that met the inclusion criteria, six involved screening for cancer, two for diabetes, and one each for abdominal aortic aneurysms, peptic ulcer, coronary heart disease and osteoporosis. Five studies reported data on anxiety, four on depression, two on general distress and eight on quality of life assessed between one week and 13 years after screening (median = 1.3 years).</p> <p>Meta-analyses revealed no significant impact of screening on longer term anxiety (pooled SMD 0.01, 95% CI -0.10, 0.11), depression (pooled SMD -0.04, 95% CI -.12, 0.20), or quality of life subscales (mental and self-assessed health pooled SMDs, respectively: 0.03; -0.01, (95% CI -.02, 0.04; 0.00, 95% CI -.04, 0.03).</p> <p>Conclusion</p> <p>Screening does not appear to have adverse emotional impacts in the longer term (> 4 weeks). Too few studies assessed outcomes before four weeks to comment on the shorter term emotional impact of screening.</p
Eigenmode Tomography of Surface Charge Oscillations of Plasmonic Nanoparticles by Electron Energy Loss Spectroscopy
Plasmonic devices designed in three dimensions enable careful tuning of optical responses for control of complex electromagnetic interactions on the nanoscale. Probing the fundamental characteristics of the constituent nanoparticle building blocks is, however, often constrained by diffraction-limited spatial resolution in optical spectroscopy. Electron microscopy techniques, including electron energy loss spectroscopy (EELS), have recently been developed to image surface plasmon resonances qualitatively at the nanoscale in three dimensions using tomographic reconstruction techniques. Here, we present an experimental realization of a distinct method that uses direct analysis of modal surface charge distributions to reconstruct quantitatively the three-dimensional eigenmodes of a silver right bipyramid on a metal oxide substrate. This eigenmode tomography removes ambiguity in two-dimensional imaging of spatially-localized plasmonic resonances, reveals substrate-induced mode degeneracy breaking in the bipyramid, and enables EELS for the analysis not of a particular electron-induced response but of the underlying geometric modes characteristic of particle surface plasmons.S.M.C. acknowledges support of a Gates Cambridge Scholarship. E.R. acknowledges support from the Royal Society's Newton International Fellowship scheme and a Trinity Hall Research Fellowship. We thank Ben Knappet for assistance with the synthesis of the silver bipyramids. We thank F.J. de la Peña for helpful discussions on the use of HYPERSPY. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Program (No. FP7/2007-2013)/ERC Grant Agreement No. 291522-3DIMAGE and the European Union's Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2)This is the final version of the article. It was first available from ACS via http://dx.doi.org/10.1021/acsphotonics.5b0042
Trapping Dynamics with Gated Traps: Stochastic Resonance-Like Phenomenon
We present a simple one-dimensional trapping model prompted by the problem of
ion current across biological membranes. The trap is modeled mimicking the
ionic channel membrane behaviour. Such voltage-sensitive channels are open or
closed depending on the value taken by a potential. Here we have assumed that
the external potential has two contributions: a determinist periodic and a
stochastic one. Our model shows a resonant-like maximum when we plot the
amplitude of the oscillations in the absorption current vs. noise intensity.
The model was solved both numerically and using an analytic approximation and
was found to be in good accord with numerical simulations.Comment: RevTex, 5 pgs, 3 figure
Effect of Non Gaussian Noises on the Stochastic Resonance-Like Phenomenon in Gated Traps
We exploit a simple one-dimensional trapping model introduced before,
prompted by the problem of ion current across a biological membrane. The
voltage-sensitive channels are open or closed depending on the value taken by
an external potential that has two contributions: a deterministic periodic and
a stochastic one. Here we assume that the noise source is colored and non
Gaussian, with a -dependent probability distribution (where is a
parameter indicating the departure from Gaussianity). We analyze the behavior
of the oscillation amplitude as a function of both and the noise
correlation time. The main result is that in addition to the resonant-like
maximum as a function of the noise intensity, there is a new resonant maximum
as a function of the parameter .Comment: Communication to LAWNP01, Proceedings to be published in Physica D,
RevTex, 8 pgs, 5 figure
Diffusion-limited reaction for the one-dimensional trap system
We have previously discussed the one-dimensional multitrap system of finite
range and found the somewhat unexpected result that the larger is the number of
imperfect traps the higher is the transmission through them. We discuss in this
work the effect of a small number of such traps arrayed along either a constant
or a variable finite spatial section. It is shown that under specific
conditions, to be described in the following, the remarked high transmission
may be obtained for this case also. Thus, compared to the theoretical large
number of traps case these results may be experimentally applied to real
phenomenaComment: 18 pages, 8 PS Figures; 3 former figures were removed, a new section
added and the representation is improve
Central Exclusive Production in QCD
We investigate the theoretical description of the central exclusive
production process, h1+h2 -> h1+X+h2. Taking Higgs production as an example, we
sum logarithmically enhanced corrections appearing in the perturbation series
to all orders in the strong coupling. Our results agree with those originally
presented by Khoze, Martin and Ryskin except that the scale appearing in the
Sudakov factor, mu=0.62 \sqrt{\hat{s}}, should be replaced with
mu=\sqrt{\hat{s}}, where \sqrt{\hat{s}} is the invariant mass of the centrally
produced system. We confirm this result using a fixed-order calculation and
show that the replacement leads to approximately a factor 2 suppression in the
cross-section for central system masses in the range 100-500 GeV.Comment: 41 pages, 19 figures; minor typos fixed; version published in JHE
Recommended from our members
Assessment of ozone photochemistry in the western North Pacific as inferred from PEM-West A observations during the fall 1991
This study examines the influence of photochemical processes on ozone distributions in the western North Pacific. The analysis is based on data generated during NASA's western Pacific Exploratory Mission (PEM-West A) during the fall of 1991. Ozone trends were best described in terms of two geographical domains: the western North Pacific rim (WNPR) and the western tropical North Pacific (WTNP). For both geographical regions, ozone photochemical destruction, D(O3), decreased more rapidly with altitude than did photochemical formation, F(O3). Thus the ozone tendency, P(O3), was typically found to be negative for z <6 km and positive for z > 6-8 km. For nearly all altitudes and latitudes, observed nonmethane hydrocarbon (NMHC) levels were shown to be of minor importance as ozone precursor species. Air parcel types producing the largest positive values of P(O3) included fresh continental boundary layer (BL) air and high-altitude (z > 7 km) parcels influenced by deep convection/lightning. Significant negative P(O3) values were found when encountering clean marine BL air or relatively clean lower free-tropospheric air. Photochemical destruction and formation fluxes for the Pacific rim region were found to exceed average values cited for marine dry deposition and stratospheric injection in the northern hemisphere by nearly a factor of 6. This region was also found to be in near balance with respect to column-integrated O3 photochemical production and destruction. By contrast, for the tropical regime column-integrated O3 showed photochemical destruction exceeding production by nearly 80%. Both transport of O3 rich midlatitude air into the tropics as well as very high-altitude (10-17 km) photochemical O3 production were proposed as possible additional sources that might explain this estimated deficit. Results from this study further suggest that during the fall time period, deep convection over Asia and Malaysia/Indonesia provided a significant source of high-altitude NOx to the western Pacific. Given that the high-altitude NOx lifetime is estimated at between 3 and 9 days, one would predict that this source added significantly to high altitude photochemical O3 formation over large areas of the western Pacific. When viewed in terms of strong seasonal westerly flow, its influence would potentially span a large part of the Pacific. Copyright 1996 by the American Geophysical Union
Occupational therapy, loneliness and social isolation : a thematic review of the literature
Background/Aims: Loneliness and social isolation are thought to have a negative impact on health and wellbeing. There is little literature that provides an explicit focus on loneliness and social isolation in occupational therapy practice. The aim of this study was to explore themes related to loneliness and social isolation in occupational therapy-related literature and consider the implications for practice.
Methods: CINAHL, Medline, Pub Med, AMed, PsycINFO, TRIP Database, and Science direct and Web of science databases were used to identify articles pertaining to occupational therapy, loneliness and social isolation.
Results: A total of 20 articles were included and three themes were identified: loneliness and social isolation are detrimental to health and wellbeing; factors associated with increased loneliness and social isolation; factors that protect against the impact of loneliness and social isolation.
Conclusions: Loneliness and social isolation have a significant impact on the health and wellbeing of the people occupational therapists work with. Occupational therapy practice should include the recognition and assessment of loneliness and social isolation, and interventions to help reduce any impacts on health and wellbeing
Second chances: Investigating athletes’ experiences of talent transfer
Talent transfer initiatives seek to transfer talented, mature individuals from one sport to another. Unfortunately talent transfer initiatives seem to lack an evidence-based direction and a rigorous exploration of the mechanisms underpinning the approach. The purpose of this exploratory study was to identify the factors which successfully transferring athletes cite as facilitative of talent transfer. In contrast to the anthropometric and performance variables that underpin current talent transfer initiatives, participants identified a range of psychobehavioral and environmental factors as key to successful transfer. We argue that further research into the mechanisms of talent transfer is needed in order to provide a strong evidence base for the methodologies employed in these initiatives
Oral tolerance to cancer can be abrogated by T regulatory cell inhibition
Oral administration of tumour cells induces an immune hypo-responsiveness known as oral tolerance. We have previously shown that oral tolerance to a cancer is tumour antigen specific, non-cross-reactive and confers a tumour growth advantage. We investigated the utilisation of regulatory T cell (Treg) depletion on oral tolerance to a cancer and its ability to control tumour growth. Balb/C mice were gavage fed homogenised tumour tissue – JBS fibrosarcoma (to induce oral tolerance to a cancer), or PBS as control. Growth of subcutaneous JBS tumours were measured; splenic tissue excised and flow cytometry used to quantify and compare systemic Tregs and T effector (Teff) cell populations. Prior to and/or following tumour feeding, mice were intraperitoneally administered anti-CD25, to inactivate systemic Tregs, or given isotype antibody as a control. Mice which were orally tolerised prior to subcutaneous tumour induction, displayed significantly higher systemic Treg levels (14% vs 6%) and faster tumour growth rates than controls (p<0.05). Complete regression of tumours were only seen after Treg inactivation and occurred in all groups - this was not inhibited by tumour feeding. The cure rates for Treg inactivation were 60% during tolerisation, 75% during tumour growth and 100% during inactivation for both tolerisation and tumour growth. Depletion of Tregs gave rise to an increased number of Teff cells. Treg depletion post-tolerisation and post-tumour induction led to the complete regression of all tumours on tumour bearing mice. Oral administration of tumour tissue, confers a tumour growth advantage and is accompanied by an increase in systemic Treg levels. The administration of anti-CD25 Ab decreased Treg numbers and caused an increase in Teffs. Most notably Treg cell inhibition overcame established oral tolerance with consequent tumor regression, especially relevant to foregut cancers where oral tolerance is likely to be induced by the shedding of tumour tissue into the gut
- …