748 research outputs found
Using the 'myVolcano' mobile phone app for citizen science in St. Vincent and the Grenadines : a pilot study
The British Geological Survey (BGS) has been working with Caribbean partners on the role of
citizen science in increasing resilience to natural hazards. The work has largely focused on the
potential use of the myVolcano smartphone app, which was developed by the BGS following the
2010 Eyafjallajökull and 2011 GrÃmsvötn eruptions in Iceland. During these eruptions the BGS
asked the UK public to collect particle samples, subsequently analysing these for ash presence to
map the distribution of ash fallout across the UK. These requests led to the development of the
myVolcano app, which was designed to capture transboundary and distal observations of volcanic
ash and emissions. The observations are made visible to other users via an interactive map built
into the app. The map interface has global coverage and the data collection methods (free-text
descriptions and photographs) are such that information about any natural hazard, anywhere in the
world, can be captured.
In 2015, BGS carried out an ESRC-DfID-NERC funded scoping study in collaboration with the
University of the West Indies’ Seismic Research Centre (UWI SRC), to test the potential use of
the app in environments affected by proximal volcanic hazards. The study focused on St. Vincent
and the Grenadines and investigated the potential for capturing a wider variety of observations for
use by the public, operational scientists and civil protection. The study, which included a
combination of desk study and remote interviews, highlighted the potential for, and challenges of,
using such an app for increasing resilience to natural hazards and the need for a follow-up study
in St Vincent.
In March 2017, a workshop and school activities were held in St. Vincent to collect feedback from
potential users of myVolcano, hereafter referred to as the pilot study. Workshop participants came
from across government, monitoring agencies, emergency response and telecommunications. As
part of the workshop, a multi-hazard scenario was ‘played out’ to stimulate discussions on the
usability of the app, data gathering and processing, and participants’ use of existing citizen science
applications. Discussions developed around data validation and quality assurance, data sharing and
presentation, local management of data by nominated scientists (e.g. to facilitate real-time decision
making) and the associated need for a locally appropriate app (i.e. no one size fits all). This last
point is particularly significant when considering the utility of an app in several countries – the
user interface, at least, requires specific tailoring to the country’s needs. Using this feedback, the
BGS Official Development Assistance (ODA) programme is currently funding collaborations
with Caribbean partners in order to modify the app to meet the local requirements, including
widening the multi-hazard application and enhancing two-way information sharing. Of particular
importance is how best to share critical information with those making observations and how to
make observations available to decision-makers and monitoring scientists in real-time (e.g.
through local management of the app)
2012-2013 The Antique Club: Pictures at an Exhibition
https://spiral.lynn.edu/conservatory_otherseasonalconcerts/1015/thumbnail.jp
Comparing P and S wave heterogeneity in the mantle
From the reprocessed data set of Engdahl and
co-workers we have carefully selected matching P and S data
for tomographic imaging. We assess data and model error
and conclude that our S model uncertainty is twice that of
the P model. We account for this in our comparison of the
perturbations in P and S-wavespeed. In accord with previous
studies we find that P and S perturbations are positively
correlated at all depths. However, in the deep mantle systematic
di fferences occur between regions that have undergone
subduction in the last 120 million years and those that
have not. In particular, below 1500 km depth ∂ ln Vs/∂ ln Vp
is signifi cantly larger in mantle regions away from subduction
than in mantle beneath convergent margins. This inference
is substantiated by wavespeed analyses with random realizations
of the slab/non-slab distribution. Through much
of the mantle there is no signi ficant correlation between bulk
sound and S-wave perturbations, but they appear to be negatively
correlated between 1700 and 2100 km depth, which
is also where the largest di erences in ∂ ln Vs/∂ ln Vp occur.
This finding supports convection models with compositional
heterogeneity in the lowermost mantle
Efficacy and tolerability of high dose "ethinylestradiol" in post-menopausal advanced breast cancer patients heavily pre-treated with endocrine agents
BACKGROUND: High dose estrogens (HDEs) were frequently used as endocrine agents prior to the introduction of tamoxifen which carries fewer side effects. Due to the development of resistance to available endocrine agents in almost all women with metastatic breast cancer, interest has renewed in the use of HDEs as yet another endocrine option that may have activity. We report our experience with one of the HDEs ("ethinylestradiol" 1 mg daily) in advanced breast cancer (locally advanced and metastatic) in post-menopausal women who had progressed on multiple endocrine agents. PATIENTS AND METHODS: According to a database of advanced breast cancer patients seen in our Unit since 1998, those who had complete set of information and fulfilled the following criteria were studied: (1) patients in whom further endocrine therapy was deemed appropriate i.e., patients who have had clinical benefit with previous endocrine agents or were not fit or unwilling to receive chemotherapy in the presence of potentially life-threatening visceral metastases; (2) disease was assessable by UICC criteria; (3) were treated with "ethinylestradiol" until they were withdrawn from treatment due to adverse events or disease progression. RESULTS: Twelve patients with a median age of 75.1 years (49.1 – 85 years) were identified. Majority (N = 8) had bony disease. They had ethinylestradiol as 3(rd )to 7(th )line endocrine therapy. One patient (8%) came off treatment early due to hepato-renal syndrome. Clinical benefit (objective response or durable stable disease for ≥ 6 months) was seen in 4 patients (33.3%) with a median duration of response of 10+ (7–36) months. The time to treatment failure was 4 (0.5–36) months. CONCLUSION: Yet unreported, high dose "ethinylestradiol" is another viable therapeutic strategy in heavily pre-treated patients when further endocrine therapy is deemed appropriate. Although it tends to carry more side effects, they may not be comparable to those of other HDEs (such as diethylstilbestrol) or chemotherapy
Tensor-scalar gravity and binary-pulsar experiments
Some recently discovered nonperturbative strong-field effects in
tensor-scalar theories of gravitation are interpreted as a scalar analog of
ferromagnetism: "spontaneous scalarization". This phenomenon leads to very
significant deviations from general relativity in conditions involving strong
gravitational fields, notably binary-pulsar experiments. Contrary to
solar-system experiments, these deviations do not necessarily vanish when the
weak-field scalar coupling tends to zero. We compute the scalar "form factors"
measuring these deviations, and notably a parameter entering the pulsar timing
observable gamma through scalar-field-induced variations of the inertia moment
of the pulsar. An exploratory investigation of the confrontation between
tensor-scalar theories and binary-pulsar experiments shows that nonperturbative
scalar field effects are already very tightly constrained by published data on
three binary-pulsar systems. We contrast the probing power of pulsar
experiments with that of solar-system ones by plotting the regions they exclude
in a generic two-dimensional plane of tensor-scalar theories.Comment: 35 pages, REVTeX 3.0, uses epsf.tex to include 9 Postscript figure
On the Detection of a Scalar Stochastic Background of Gravitational Waves
In the near future we will witness the coming to a full operational regime of
laser interferometers and resonant mass detectors of spherical shape. In this
work we study the sensitivity of pairs of such gravitational wave detectors to
a scalar stochastic background of gravitational waves. Our computations are
carried out both for minimal and non minimal coupling of the scalar fields.Comment: 25 pages, 3 figure
Gravitational-wave versus binary-pulsar tests of strong-field gravity
Binary systems comprising at least one neutron star contain strong
gravitational field regions and thereby provide a testing ground for
strong-field gravity. Two types of data can be used to test the law of gravity
in compact binaries: binary pulsar observations, or forthcoming
gravitational-wave observations of inspiralling binaries. We compare the
probing power of these two types of observations within a generic two-parameter
family of tensor-scalar gravitational theories. Our analysis generalizes
previous work (by us) on binary-pulsar tests by using a sample of realistic
equations of state for nuclear matter (instead of a polytrope), and goes beyond
a previous study (by C.M. Will) of gravitational-wave tests by considering more
general tensor-scalar theories than the one-parameter Jordan-Fierz-Brans-Dicke
one. Finite-size effects in tensor-scalar gravity are also discussed.Comment: 23 pages, REVTeX 3.0, uses epsf.tex to include 5 postscript figures
(2 paragraphs and a 5th figure added at the end of section IV + minor
changes
WMAP constraints on scalar-tensor cosmology and the variation of the gravitational constant
We present observational constraints on a scalar-tensor gravity theory by
test for CMB anisotropy spectrum. We compare the WMAP temperature
power spectrum with the harmonic attractor model, in which the scalar field has
its harmonic effective potential with curvature in the Einstein
conformal frame and the theory relaxes toward Einstein gravity with time. We
found that the present value of the scalar coupling, i.e. the present level of
deviation from Einstein gravity , is bounded to be smaller than
(), and () for . This constraint is much stronger than the bound from the solar
system experiments for large models, i.e., and 0.3 in
and limits, respectively. Furthermore, within the framework
of this model, the variation of the gravitational constant at the recombination
epoch is constrained as , and
.Comment: 7 page
A preliminary study of the effect of closed incision management with negative pressure wound therapy over high-risk incisions
Background
Certain postoperative wounds are recognised to be associated with more complications than others and may be termed high-risk. Wound healing can be particularly challenging following high-energy trauma where wound necrosis and infection rates are high. Surgical incision for joint arthrodesis can also be considered high-risk as it requires extensive and invasive surgery and postoperative distal limb swelling and wound dehiscence are common. Recent human literature has investigated the use of negative pressure wound therapy (NPWT) over high-risk closed surgical incisions and beneficial effects have been noted including decreased drainage, decreased dehiscence and decreased infection rates. In a randomised, controlled study twenty cases undergoing distal limb high-energy fracture stabilisation or arthrodesis were randomised to NPWT or control groups. All cases had a modified Robert-Jones dressing applied for 72 h postoperatively and NPWT was applied for 24 h in the NPWT group. Morphometric assessment of limb circumference was performed at six sites preoperatively, 24 and 72 h postoperatively. Wound discharge was assessed at 24 and 72 h. Postoperative analgesia protocol was standardised and a Glasgow Composite Measure Pain Score (GCPS) carried out at 24, 48 and 72 h. Complications were noted and differences between groups were assessed.
Results
Percentage change in limb circumference between preoperative and 24 and 72 h postoperative measurements was significantly less at all sites for the NPWT group with exception of the joint proximal to the surgical site and the centre of the operated bone at 72 h. Median discharge score was lower in the NPWT group than the control group at 24 h. No significant differences in GCPS or complication rates were noted.
Conclusions
Digital swelling and wound discharge were reduced when NPWT was employed for closed incision management. Larger studies are required to evaluate whether this will result in reduced discomfort and complication rates postoperatively
Shifting attention in viewer- and object-based reference frames after unilateral brain injury
The aims of the present study were to investigate the respective roles that object- and viewer-based reference frames play in reorienting visual attention, and to assess their influence after unilateral brain injury. To do so, we studied 16 right hemisphere injured (RHI) and 13 left hemisphere injured (LHI) patients. We used a cueing design that manipulates the location of cues and targets relative to a display comprised of two rectangles (i.e., objects). Unlike previous studies with patients, we presented all cues at midline rather than in the left or right visual fields. Thus, in the critical conditions in which targets were presented laterally, reorienting of attention was always from a midline cue. Performance was measured for lateralized target detection as a function of viewer-based (contra- and ipsilesional sides) and object-based (requiring reorienting within or between objects) reference frames. As expected, contralesional detection was slower than ipsilesional detection for the patients. More importantly, objects influenced target detection differently in the contralesional and ipsilesional fields. Contralesionally, reorienting to a target within the cued object took longer than reorienting to a target in the same location but in the uncued object. This finding is consistent with object-based neglect. Ipsilesionally, the means were in the opposite direction. Furthermore, no significant difference was found in object-based influences between the patient groups (RHI vs. LHI). These findings are discussed in the context of reference frames used in reorienting attention for target detection
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