587 research outputs found
Application of flood risk modelling in a web-based geospatial decision support tool for coastal adaptation to climate change
This is the discussion paper that was under review for the for the journal Natural Hazards and Earth
System Sciences (NHESS).The final paper is available from the publisher via DOI: 10.5194/nhess-15-1457-2015A pressing problem facing coastal decision makers
is the conversion of âhigh-levelâ but plausible climate
change assessments into an effective basis for climate change
adaptation at the local scale. Here, we describe a web-based,
geospatial decision support tool (DST) that provides an assessment
of the potential flood risk for populated coastal
lowlands arising from future sea-level rise, coastal storms,
and high river flows. This DST has been developed to support
operational and strategic decision making by enabling
the user to explore the flood hazard from extreme events,
changes in the extent of the flood-prone areas with sea-level
rise, and thresholds of sea-level rise where current policy and
resource options are no longer viable. The DST is built in an
open-source GIS that uses freely available geospatial data.
Flood risk assessments from a combination of LISFLOODFP
and SWAB (Shallow Water And Boussinesq) models are
embedded within the tool; the user interface enables interrogation
of different combinations of coastal and river events
under rising-sea-level scenarios. Users can readily vary the
input parameters (sea level, storms, wave height and river
flow) relative to the present-day topography and infrastructure
to identify combinations where significant regime shifts
or âtipping pointsâ occur. Two case studies demonstrate the
attributes of the DST with respect to the wider coastal community
and the UK energy sector. Examples report on the assets
at risk and illustrate the extent of flooding in relation to
infrastructure access. This informs an economic assessment
of potential losses due to climate change and thus provides
local authorities and energy operators with essential information
on the feasibility of investment for building resilience
into vulnerable components of their area of responsibilit
Melaena with Peutz-Jeghers syndrome: a case report
Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction.
Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed.
Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences
A coastal vulnerability assessment for planning climate resilient infrastructure
publisher: Elsevier articletitle: A coastal vulnerability assessment for planning climate resilient infrastructure journaltitle: Ocean & Coastal Management articlelink: https://doi.org/10.1016/j.ocecoaman.2018.06.007 content_type: article copyright: © 2018 The Authors. Published by Elsevier Ltd
Neuro-immune signatures in chronic low back pain subtypes
We recently showed that patients with different chronic pain conditions (such as chronic low back pain, fibromyalgia, migraine, and Gulf War Illness) demonstrated elevated brain and/or spinal cord levels of the glial marker 18âkDa translocator protein, which suggests that neuroinflammation might be a pervasive phenomenon observable across multiple etiologically heterogeneous pain disorders. Interestingly, the spatial distribution of this neuroinflammatory signal appears to exhibit a degree of disease specificity (e.g. with respect to the involvement of the primary somatosensory cortex), suggesting that different pain conditions may exhibit distinct âneuroinflammatory signaturesâ. To further explore this hypothesis, we tested whether neuroinflammatory signal can characterize putative etiological subtypes of chronic low back pain patients based on clinical presentation. Specifically, we explored neuroinflammation in patients whose chronic low back pain either did or did not radiate to the leg (i.e. âradicularâ vs. âaxialâ back pain).
Fifty-four chronic low back pain patients, twenty-six with axial back pain (43.7â±â16.6 y.o. [mean±SD]) and twenty-eight with radicular back pain (48.3â±â13.2 y.o.), underwent PET/MRI with [11C]PBR28, a second-generation radioligand for the 18âkDa translocator protein. [11C]PBR28 signal was quantified using standardized uptake values ratio (validated against volume of distribution ratio; nâ=â23). Functional MRI data were collected simultaneously to the [11C]PBR28 data 1) to functionally localize the primary somatosensory cortex back and leg subregions and 2) to perform functional connectivity analyses (in order to investigate possible neurophysiological correlations of the neuroinflammatory signal). PET and functional MRI measures were compared across groups, cross-correlated with one another and with the severity of âfibromyalgianessâ (i.e. the degree of pain centralization, or ânociplastic painâ). Furthermore, statistical mediation models were employed to explore possible causal relationships between these three variables.
For the primary somatosensory cortex representation of back/leg, [11C]PBR28 PET signal and functional connectivity to the thalamus were: 1) higher in radicular compared to axial back pain patients, 2) positively correlated with each other and 3) positively correlated with fibromyalgianess scores, across groups. Finally, 4) fibromyalgianess mediated the association between [11C]PBR28 PET signal and primary somatosensory cortex-thalamus connectivity across groups.
Our findings support the existence of âneuroinflammatory signaturesâ that are accompanied by neurophysiological changes, and correlate with clinical presentation (in particular, with the degree of nociplastic pain) in chronic pain patients. These signatures may contribute to the subtyping of distinct pain syndromes and also provide information about inter-individual variability in neuro-immune brain signals, within diagnostic groups, that could eventually serve as targets for mechanism-based precision medicine approaches
Beautiful Mirrors at the LHC
We explore the "Beautiful Mirrors" model, which aims to explain the measured
value of , discrepant at the level. This scenario
introduces vector-like quarks which mix with the bottom, subtly affecting its
coupling to the . The spectrum of the new particles consists of two
bottom-like quarks and a charge -4/3 quark, all of which have electroweak
interactions with the third generation. We explore the phenomenology and
discovery reach for these new particles at the LHC, exploring single mirror
quark production modes whose rates are proportional to the same mixing
parameters which resolve the anomaly. We find that for mirror quark
masses is required to
reasonably establish the scenario and extract the relevant mixing parameters.Comment: version to be published in JHE
LHC Signatures of a Minimal Supersymmetric Hidden Valley
We investigate the LHC signals of a minimal supersymmetric hidden valley. Our
theory consists of the supersymmetric Standard Model along with a light hidden
U(1)_x gauge multiplet and a pair of hidden chiral superfields that
spontaneously break the new Abelian gauge symmetry near a GeV. The visible and
hidden sectors interact exclusively through supersymmetric gauge kinetic
mixing. We perform a thorough examination of the hidden decay cascades
initiated by the lightest Standard Model superpartner and we study the range of
LHC signals they can produce. In particular, we find parameter regions that
give rise to missing energy, single and multiple lepton jets, and displaced
vertices. Given the simplicity of the underlying theory and the broad range of
collider signals it can produce, we propose that this model is a useful
benchmark for LHC studies of (supersymmetric) hidden valleys.Comment: 45 pages, 15 figures; typos corrected but conclusions unchange
Scaling Patterns for QCD Jets
Jet emission at hadron colliders follows simple scaling patterns. Based on
perturbative QCD we derive Poisson and staircase scaling for final state as
well as initial state radiation. Parton density effects enhance staircase
scaling at low multiplicities. We propose experimental tests of our theoretical
findings in Z+jets and QCD gap jets production based on minor additions to
current LHC analyses.Comment: 36 pages, 16 figure
A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
A fourth chiral generation, with in the range GeV and a moderate value of the CP-violating phase can explain the
anomalous like-sign dimuon charge asymmetry observed recently by the D0
collaboration. The required parameters are found to be consistent with
constraints from other and decays. The presence of such quarks, apart
from being detectable in the early stages of the LHC, would also have important
consequences in the electroweak symmetry breaking sector.Comment: 18 pages, 9 figures, Figure 1 is modified, more discussions are added
in section 2. new references adde
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