422 research outputs found
Therapeutic attitudes and the acquisition of competence during CBT training
Psychotherapy has differentiated into models of practice based on diverse principles. Current policies in the UK favour expansion of empirically supported treatments, especially cognitive behaviour therapy (CBT). This is likely to result in therapists seeking training in CBT after previously adhering to other models.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
A review of the current state of the art of physiologically-based tests for measuring human dermal in vitro bioavailability of polycyclic aromatic hydrocarbons (PAH) in soil
Polycyclic Aromatic Hydrocarbons are classed as Persistent Organic Pollutants, a large group of compounds that share similar characteristics. They are lipophilic, resistant to degradation in the environment and harmful to human and environmental health. Soil has been identified as the primary reservoir for Polycyclic Aromatic Hydrocarbons in the United Kingdom. This study reviews the literature associated with, or is relevant to, the measurement and modelling of dermal absorption of Polycyclic Aromatic Hydrocarbons from soils. The literature illustrates the use of in vivo, in vitro and in silico methods from a wide variety of scientific disciplines including occupational and environmental exposure, medical, pharmaceutical and cosmetic research and associated mathematical modelling. The review identifies a number of practical shortcomings which must be addressed if dermal bioavailability tests are to be applied to laboratory analysis of contaminated soils for human health risk assessment
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Is the Sevier Desert Reflection of West-Central Utah a Normal Fault?: Comment and Reply
Forum discussion on an article originally by Anders et al. Allmendinger and Royse critique Anders et al.'s argument, to which Anders et al. responds.
Critique abstract: The continuing discussion of the Sevier Desert region, almost 20 years after MacDonald’s (1976) classic paper, provides a measure of the significance of the region as well as the non-uniqueness of seismic reflection data interpretation. The article by Anders and Christie-Blick (1994) and the nearly simultaneous publication of similar ideas by Hamilton (1994) raise important questions. The interpretation of a Sevier Desert detachment has always been a hypothesis to be tested rather than a fact. In our opinion, however, Anders and Christie-Blick and Hamilton have ignored a variety of basic geologic data requiring the presence of a major low-angle normal fault on the east side of the Sevier Desert basin.
Response abstract: We concur with Allmendinger and Royse’s assessment of the detachment interpretation for the Sevier Desert reflection as a ‘‘hypothesis to be tested.’’ We reported on an attempt to do just that: to look for evidence for fault-related deformation in samples from two boreholes that intersect this feature. The absence of evidence for cataclasis in the inferred hanging-wall block or ductile deformation in the footwall naturally raises some interesting issues for the tectonic interpretation of the Sevier Desert. In drawing attention to these issues, we have not ‘‘ignored’’ any basic geologic data, nor are we aware of any data that ‘‘require’’ the presence of a major low-angle normal fault
Prebiotic Homochirality as a Critical Phenomenon
The development of prebiotic homochirality on early-Earth or another
planetary platform may be viewed as a critical phenomenon. It is shown, in the
context of spatio-temporal polymerization reaction networks, that environmental
effects -- be them temperature surges or other external disruptions -- may
destroy any net chirality previously produced. In order to understand the
emergence of prebiotic homochirality it is important to model the coupling of
polymerization reaction networks to different planetary environments.Comment: 6 Pages, 1 Figure, In Press: Origins of Life and Evolution of
Biosphere
Quasar bolometric corrections: theoretical considerations
Bolometric corrections based on the optical-to-ultraviolet continuum spectrum
of quasars are widely used to quantify their radiative output, although such
estimates are affected by a myriad of uncertainties, such as the generally
unknown line-of-sight angle to the central engine. In order to shed light on
these issues, we investigate the state-of-the-art models of Hubeny et al. that
describe the continuum spectrum of thin accretion discs and include
relativistic effects. We explore the bolometric corrections as a function of
mass accretion rates, black hole masses and viewing angles, restricted to the
parameter space expected for type-1 quasars. We find that a nonlinear
relationship log L_bol=A + B log(lambda L_lambda) with B<=0.9 is favoured by
the models and becomes tighter as the wavelength decreases. We calculate from
the model the bolometric corrections corresponding to the wavelengths lambda =
1450A, 3000A and 5100A. In particular, for lambda=3000A we find A=9.24 +- 0.77
and B=0.81 +- 0.02. We demonstrate that the often-made assumption that quasars
emit isotropically may lead to severe systematic errors in the determination of
L_bol, when using the method of integrating the "big blue bump" spectrum. For a
typical viewing angle of ~30 degrees to the quasar central engine, we obtain
that the value of L_bol resulting from the isotropy assumption has a systematic
error of ~30% high compared to the value of L_bol which incorporates the
anisotropic emission of the accretion disc. These results are of direct
relevance to observational determinations of the bolometric luminosities of
quasars, and may be used to improve such estimates.Comment: 9 pages, 11 figures, accepted for publication in MNRA
A novel bifunctional oxygen GDE for alkaline secondary batteries
AbstractThis paper describes a novel procedure for the fabrication of a gas diffusion electrode (GDE) suitable for use as a bifunctional oxygen electrode in alkaline secondary batteries. The electrode is fabricated by pre-forming a PTFE-bonded nickel powder layer on a nickel foam substrate followed by deposition of NiCo2O4 spinel electrocatalyst by dip coating in a nitrate solution and thermal decomposition. The carbon-free composition avoids concerns over carbon corrosion at the potentials for oxygen evolution. The electrode shows acceptable overpotentials for both oxygen evolution and oxygen reduction at current densities up to 100mAcm−2. Stable performance during >100 successive, 1h oxygen reduction/evolution cycles at a current density of 20mAcm−2 in 8M NaOH at 333K was achieved
Counting Complex Disordered States by Efficient Pattern Matching: Chromatic Polynomials and Potts Partition Functions
Counting problems, determining the number of possible states of a large
system under certain constraints, play an important role in many areas of
science. They naturally arise for complex disordered systems in physics and
chemistry, in mathematical graph theory, and in computer science. Counting
problems, however, are among the hardest problems to access computationally.
Here, we suggest a novel method to access a benchmark counting problem, finding
chromatic polynomials of graphs. We develop a vertex-oriented symbolic pattern
matching algorithm that exploits the equivalence between the chromatic
polynomial and the zero-temperature partition function of the Potts
antiferromagnet on the same graph. Implementing this bottom-up algorithm using
appropriate computer algebra, the new method outperforms standard top-down
methods by several orders of magnitude, already for moderately sized graphs. As
a first application, we compute chromatic polynomials of samples of the simple
cubic lattice, for the first time computationally accessing three-dimensional
lattices of physical relevance. The method offers straightforward
generalizations to several other counting problems.Comment: 7 pages, 4 figure
A novel bifunctional oxygen GDE for alkaline secondary batteries
This paper describes a novel procedure for the fabrication of a gas diffusion electrode (GDE) suitable for use as a bifunctional oxygen electrode in alkaline secondary batteries. The electrode is fabricated by pre-forming a PTFE-bonded nickel powder layer on a nickel foam substrate followed by deposition of NiCo2O4 spinel electrocatalyst by dip coating in a nitrate solution and thermal decomposition. The carbon-free composition avoids concerns over carbon corrosion at the potentials for oxygen evolution. The electrode shows acceptable overpotentials for both oxygen evolution and oxygen reduction at current densities up to 100 mA cm−2. Stable performance during >100 successive, 1 h oxygen reduction/evolution cycles at a current density of 20 mA cm−2 in 8 M NaOH at 333 K was achieved.European Commissio
Prevalence of defined ultrasound findings of unknown significance at the second trimester fetal anomaly scan and their association with adverse pregnancy outcomes : the Welsh study of mothers and babies population-based cohort
Article first published online: 20 NOV 2015 This is an open access article under the terms of the Creative Commons Attribution License Acknowledgements We gratefully acknowledge the contribution of Rosemary Johnson (Antenatal Screening Wales, Public Health Wales NHS Trust) for her input into the design, coordination and implementation of this study. We would also like to thank the individuals within the following organisations who contributed to the management or running of the study: Antenatal Screening Wales; the antenatal screening coordinators, midwives and superintendent sonographers at all participating Health Boards (Abertawe Bro Morgannwg University Health Board, Aneurin Bevan University Health Board, Betsi Cadwaladr University Health Board, Cardiff and Vale University Health Board, Cwm Taf University Health Board and Hywel Dda University Health Board); and the members of the quality assurance expert panel. We also acknowledge the substantial contribution of all women who participated in the study.Peer reviewedPublisher PD
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