2,176 research outputs found
Interactions between apparently ‘primary’ weather--‐driven hazards and their cost
A statistical analysis of the largest weather-driven hazards in the UK contradicts the typical view that each predominates in distinct events that do not interact with those of other hazard types (i.e., are 'primary'); this potentially has implications for any multi-hazard environments globally where some types of severe event are still thought to occur independently. By a first co-investigation of long (1884–2008) meteorological time-series and nationwide insurance losses for UK domestic houses (averaging £1.1 billion/yr), new systematic interactions within a 1 year timeframe are identified between temporally-distinct floods, winter wind storms, and shrink–swell subsidence events (P < 0.03); this increases costs by up to £0.3 billion/yr (i.e., 26%), although impacts will be spatially variable depending upon the interplay of hazards. 'Memory' required in the environmental system to cause these intra-annual links between event types appears to reside in soil moisture and, tentatively, sea surface temperatures. Similar, unidentified interactions between non-synchronous events are likely worldwide, and the analytical methods we have developed to identify and quantify them are suitable for application to meteorological, geological (e.g., volcanic) and cryospheric (e.g., avalanches) hazards
The incidence of scarring on the dorsum of the hand
When undertaking image comparison of the hand between accused and perpetrator, it is not unusual for scars to be identified on the back of the hand. To investigate the occurrence of scarring in a discreet sample, a database of 238 individuals was examined, and the dorsum of the right and left hands was gridded for each individual. The position, size and type of scar were recorded within each grid. It was found that, in general, males exhibited a higher incidence of scarring than females. However, males were more likely to show scarring on their left hand whereas females were more likely to exhibit scarring on their right hand. Contrary to the literature, scarring was not most prevalent along the borders of the hand but occurred more frequently in association with the index and middle finger corridor regions. Surgical scars were rare as were large scars whereas linear scars smaller than 6 mm were the most frequently identified. Close to half of the sample did not exhibit scarring on one hand. The importance of understanding the pattern of scarring on the back of the hand is discussed in the light of forensic image comparison analysis
Assessment of multispectral and hyperspectral imaging systems for digitisation of a Russian icon
In a study of multispectral and hyperspectral reflectance imaging, a Round Robin Test assessed the performance of different systems for the spectral digitisation of artworks. A Russian icon, mass-produced in Moscow in 1899, was digitised by ten institutions around Europe. The image quality was assessed by observers, and the reflectance spectra at selected points were reconstructed to characterise the icon’s colourants and to obtain a quantitative estimate of accuracy. The differing spatial resolutions of the systems affected their ability to resolve fine details in the printed pattern. There was a surprisingly wide variation in the quality of imagery, caused by unwanted reflections from both glossy painted and metallic gold areas of the icon’s surface. Specular reflection also degraded the accuracy of the reconstructed reflectance spectrum in some places, indicating the importance of control over the illumination geometry. Some devices that gave excellent results for matte colour charts proved to have poor performance for this demanding test object. There is a need for adoption of standards for digitising cultural heritage objects to achieve greater consistency of system performance and image quality.This article arose out of a Short-Term Scientific Mission (STSM) conducted by Tatiana Vitorino when visiting University College London during a 2-week period in late October 2015. The research was carried out under the auspices of the European COST Action TD1201 Colour and Space in Cultural Heritage (COSCH). The project website is at http://www.cosch.info. Under the COST rules, TV received funding for travel and accommodation expenses, and all coauthors were able to claim travel expenses to attend the subsequent COSCH project meeting. No other funding was received from COSCH for labour or equipment and all work was done on a voluntary pro bono basis.info:eu-repo/semantics/publishedVersio
Evidence of a Clear Atmosphere for WASP-62b: The Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone
Exoplanets with cloud-free, haze-free atmospheres at the pressures probed by transmission spectroscopy represent a
valuable opportunity for detailed atmospheric characterization and precise chemical abundance constraints. We present the
first optical to infrared (0.3−5 μm) transmission spectrum of the hot Jupiter WASP-62b, measured with Hubble/STIS and
Spitzer/IRAC. The spectrum is characterized by a 5.1σ detection of Na I absorption at 0.59 μm, in which the pressurebroadened wings of the Na D-lines are observed from space for the first time. A spectral feature at 0.4 μm is tentatively
attributed to SiH at 2.1σ confidence. Our retrieval analyses are consistent with a cloud-free atmosphere without significant
contamination from stellar heterogeneities. We simulate James Webb Space Telescope (JWST) observations, for a
combination of instrument modes, to assess the atmospheric characterization potential of WASP-62b. We demonstrate that
JWST can conclusively detect Na, H2O, FeH, NH3, CO, CO2, CH4, and SiH within the scope of its Early Release Science
(ERS) program. As the only transiting giant planet currently known in the JWST Continuous Viewing Zone, WASP-62b
could prove a benchmark giant exoplanet for detailed atmospheric characterization in the James Webb era
Ferromagnetism in semiconductors and oxides: prospects from a ten years' perspective
Over the last decade the search for compounds combining the resources of
semiconductors and ferromagnets has evolved into an important field of
materials science. This endeavour has been fuelled by continual demonstrations
of remarkable low-temperature functionalities found for ferromagnetic
structures of (Ga,Mn)As, p-(Cd,Mn)Te, and related compounds as well as by ample
observations of ferromagnetic signatures at high temperatures in a number of
non-metallic systems. In this paper, recent experimental and theoretical
developments are reviewed emphasising that, from the one hand, they disentangle
many controversies and puzzles accumulated over the last decade and, on the
other, offer new research prospects.Comment: review, 13 pages, 8 figures, 109 reference
Localisation of RNAs into the germ plasm of vitellogenic xenopus oocytes
We have studied the localisation of mRNAs in full-grown Xenopus laevis oocytes by injecting fluorescent RNAs, followed by confocal microscopy of the oocyte cortex. Concentrating on RNA encoding the Xenopus Nanos homologue, nanos1 (formerly Xcat2), we find that it consistently localised into aggregated germ plasm ribonucleoprotein (RNP) particles, independently of cytoskeletal integrity. This implies that a diffusion/entrapment-mediated mechanism is active, as previously reported for previtellogenic oocytes. Sometimes this was accompanied by localisation into scattered particles of the “late”, Vg1/VegT pathway; occasionally only late pathway localisation was seen. The Xpat RNA behaved in an identical fashion and for neither RNA was the localisation changed by any culture conditions tested. The identity of the labelled RNP aggregates as definitive germ plasm was confirmed by their inclusion of abundant mitochondria and co-localisation with the germ plasm protein Hermes. Further, the nanos1/Hermes RNP particles are interspersed with those containing the germ plasm protein Xpat. These aggregates may be followed into the germ plasm of unfertilized eggs, but with a notable reduction in its quantity, both in terms of injected molecules and endogenous structures. Our results conflict with previous reports that there is no RNA localisation in large oocytes, and that during mid-oogenesis even germ plasm RNAs localise exclusively by the late pathway. We find that in mid oogenesis nanos1 RNA also localises to germ plasm but also by the late pathway. Late pathway RNAs, Vg1 and VegT, also may localise into germ plasm. Our results support the view that mechanistically the two modes of localisation are extremely similar, and that in an injection experiment RNAs might utilise either pathway, the distinction in fates being very subtle and subject to variation. We discuss these results in relation to their biological significance and the results of others
Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
Recent progress in understanding the topological properties of condensed
matter has led to the discovery of time-reversal invariant topological
insulators. Because of limitations imposed by nature, topologically non-trivial
electronic order seems to be uncommon except in small-band-gap semiconductors
with strong spin-orbit interactions. In this Article we show that artificial
electromagnetic structures, known as metamaterials, provide an attractive
platform for designing photonic analogues of topological insulators. We
demonstrate that a judicious choice of the metamaterial parameters can create
photonic phases that support a pair of helical edge states, and that these edge
states enable one-way photonic transport that is robust against disorder.Comment: 13 pages, 3 figure
A Realistic Radiative Fermion Mass Hierarchy in Non-supersymmetric SO(10)
A non-supersymmetric grand unified theory can exhibit a "radiative fermion
mass hierarchy", in which the heavier quarks and leptons get mass at tree level
and the lighter ones get mass from loop diagrams. Recently the first predictive
model of this type was proposed. Here it is analyzed numerically and it is
shown to give an excellent fit to the quark and lepton masses and mixings,
including the CP phase violating phase . A relation between the
neutrino angle and the atmospheric neutrino angle is obtainedComment: 13 pages, 4 figures, RevTeX
The perception of disability by community groups: Stories of local understanding, beliefs and challenges in a rural part of Kenya
Cultural narratives on disability have received much attention over the past few decades. In contexts of poverty, limited information and everyday challenges associated with having, or caring for someone with a disability, different understandings have emerged. A project was set up to promote disability awareness in neighborhood communities in a rural part of Kenya, using a process of reflection and education. This paper reports on the first aspect–reflection. The aim was to investigate local understanding of disability as a co-constructed concept. The research questions were: 1. What cultural beliefs shape local understanding of disability? 2. What challenges are perceived to be associated with disability? A phenomenological approach was adopted. Focus group discussions were conducted with twenty-one community groups involving 263 participants and audio-recorded. The data were transcribed and thematic analysis was carried out. Visual maps were created to illustrate any interconnections, before establishing the final conclusions. Local beliefs attributed disability to: human transgression of social conventions, particularly concerning inappropriate family relations, which invoked a curse; supernatural forces affecting the child; the will of God; unexplained events; and biomedical factors. Challenges associated with disability related to the burden of caregiving and perceived barriers to inclusion, with stress as a shared bi-product. Local understanding of disability in this rural part of Kenya demonstrated overlapping explanations and plurality of beliefs. Two possible interpretations are offered. Firstly, oscillation between explanatory lines demonstrated instability, affecting broader acceptance of disability. Secondly, and more positively, in the face of challenges, the desire to make sense of the existing situation, reflected a healthy pluralism
Fractional quantum Hall effect in a quantum point contact at filling fraction 5/2
Recent theories suggest that the excitations of certain quantum Hall states
may have exotic braiding statistics which could be used to build topological
quantum gates. This has prompted an experimental push to study such states
using confined geometries where the statistics can be tested. We study the
transport properties of quantum point contacts (QPCs) fabricated on a
GaAs/AlGaAs two dimensional electron gas that exhibits well-developed
fractional quantum Hall effect, including at bulk filling fraction 5/2. We find
that a plateau at effective QPC filling factor 5/2 is identifiable in point
contacts with lithographic widths of 1.2 microns and 0.8 microns, but not 0.5
microns. We study the temperature and dc-current-bias dependence of the 5/2
plateau in the QPC, as well as neighboring fractional and integer plateaus in
the QPC while keeping the bulk at filling factor 3. Transport near QPC filling
factor 5/2 is consistent with a picture of chiral Luttinger liquid edge-states
with inter-edge tunneling, suggesting that an incompressible state at 5/2 forms
in this confined geometry
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