220 research outputs found
Bed-material transport rate derived from delta progradation in a small alpine basin, Fitzsimmons Creek, coast mountains, British Columbia
A sediment budget was determined for Fitzsimmons Creek in order to assess the long-term bed-material efflux from a high-energy, debris-flow dominated alpine stream in the Coast Mountains of British Columbia. The primary component of the thesis (Part1) examines the long-term bed-material transport rate from morphologic data, sonar bathymetry, and ground-penetrating radar surveys of the fan-delta built by Fitzsimmons Creek and recorded on sequential aerial photography for the period 1947-1999. The average annual bed-material transport rate is 1.60 ± 0.28 104 Mg yr-1 for the 52-year period, with a range of 2.20 x 104 Mg yr1 for decadal estimates. Considerable temporal variability of the average bed-material efflux is evident over the 52-year record. The length of time required to measure a stable average annual bed-material transport rate in this particular system appears to be not less than 50 years. A secondary component of the thesis (Part 2) examines the total sediment budget based on direct measurements of bed-material accumulated in the fan-delta and estimates of suspended-sediment over the 52-year period. The long-term minimum specific sediment yield is 0.57 ± 0.14 Mg km-2 day-1 based on direct measurements and the estimate of the specific sediment yield for this system is 0. 90 ± 0 .48 Mg km- 2 day-1. A significant proportion of the total sediment load (averaging 49% over the 52-years) is deposited as bed-material in Fitzsimmons Creek\u27s fan-delta
Don’t turn your back on the symptoms of psychosis : a proof-of-principle, quasi-experimental public health trial to reduce the duration of untreated psychosis in Birmingham, UK
Background: Reducing the duration of untreated psychosis (DUP) is an aspiration of international guidelines for first episode psychosis; however, public health initiatives have met with mixed results. Systematic reviews suggest that greater focus on the sources of delay within care pathways, (which will vary between healthcare settings) is needed to achieve sustainable reductions in DUP (BJP 198: 256-263; 2011).
Methods/Design: A quasi-experimental trial, comparing a targeted intervention area with a ‘detection as usual’ area in the same city. A proof-of–principle trial, no a priori assumptions are made regarding effect size; key outcome will be an estimate of the potential effect size for a definitive trial. DUP and number of new cases will be collected over an 18-month period in target and control areas and compared; historical data on DUP collected in both areas over the previous three years, will serve as a benchmark. The intervention will focus on reducing two significant DUP component delays within the overall care pathway: delays within the mental health service and help-seeking delay.
Discussion: This pragmatic trial will be the first to target known delays within the care pathway for those with a first episode of psychosis. If successful, this will provide a generalizable methodology that can be implemented in a variety of healthcare contexts with differing sources of delay.
Trial registration: http://www.controlled-trials.com/ISRCTN45058713
Keywords: Public mental health campaign, First-episode psychosis, Early detection, Duration of untreated psychosis, Youth mental healt
Grommet Surgery in Children With Orofacial Clefts in England.
OBJECTIVE: To assess grommet insertion practice in the first 5 years of life among children with an orofacial cleft in England. DESIGN: Analysis of national administrative data of hospital admissions. SETTING: National Health Service hospitals, England. PATIENTS: Patients born between 1997 and 2005 who underwent surgical cleft repair. INTERVENTION: Children receiving grommets before the age of 5 years. OUTCOME MEASURES: The proportion of children receiving grommets before the age of 5 years, the timing of the first grommet insertion, and the proportion of children having repeat grommet insertions were examined according to cleft type, the absence or presence of additional anomalies, socioeconomic deprivation, and region of residence. RESULTS: The study included 8,269 children. Before the age of 5 years, 3,015 (36.5%) children received grommets. Of these, 33.2% received their first grommets at primary cleft repair and 33.3% underwent multiple grommet insertion procedures. The most common age for the first procedure was between 6 and 12 months. Children with a cleft affecting the palate were more likely to receive grommets than children with a cleft lip alone (45.5% versus 4.5%). Grommet insertion practice also varied according to year of birth, absence or presence of additional anomalies, socioeconomic deprivation, and region of residence. CONCLUSION: Grommets practice in children with a cleft appears to vary according to their clinical characteristics. The differences in practice observed according to deprivation and region of residence need to be further explored
Wigner's Friend paradoxes: consistency with weak-contextual and weak-macroscopic realism models
Wigner's friend paradoxes highlight contradictions between measurements made
by Friends inside a laboratory and superobservers outside a laboratory, who
have access to an entangled state of the measurement apparatus. The
contradictions lead to no-go theorems for observer-independent facts, thus
challenging concepts of objectivity. Here, we examine the paradoxes from the
perspective of establishing consistency with macroscopic realism. We present
versions of the Brukner-Wigner-friend and Frauchiger-Renner paradoxes in which
the spin- system measured by the Friends corresponds to two
macroscopically distinct states. The local unitary operations that
determine the measurement setting are carried out using nonlinear
interactions, thereby ensuring measurements need only distinguish between the
macroscopically distinct states. The macroscopic paradoxes are perplexing,
seemingly suggesting there is no objectivity in a macroscopic limit. However,
we demonstrate consistency with a contextual weak form of macroscopic realism
(wMR): The premise wMR asserts that the system can be considered to have a
definite spin outcome , at the time after the system has
undergone the unitary rotation to prepare it in a suitable pointer
basis. We further show that the paradoxical outcomes imply failure of
deterministic macroscopic local realism, and arise when there are unitary
interactions occurring due to a change of measurement setting at
both sites, with respect to the state prepared by each Friend. In models which
validate wMR, there is a breakdown of a subset of the assumptions that
constitute the Bell-Locality premise. A similar interpretation involving a weak
contextual form of realism exists for the original paradoxes
Don’t turn your back on the symptoms of psychosis : the results of a proof-of-principle, quasi-experimental intervention to reduce duration of untreated psychosis
Background
No evidence based approach to reduce duration of untreated psychosis (DUP) has been effective in the UK. Existing interventions have many components and have been difficult to replicate. The majority of DUP in Birmingham, UK is accounted for by delays within mental health services (MHS) followed by help-seeking delay and, we hypothesise, these require explicit targeting. This study examined the feasibility and impact of an intervention to reduce DUP, targeting help-seeking and MHSs delays.
Methods
A dual-component intervention, comprising a direct care pathway, for 16-25 year olds, and a community psychosis awareness campaign, using our youth-friendly website as the central hub, was implemented, targeting the primary sources of care pathway delays experienced by those with long DUP. Evaluation, using a quasi-experimental, design compared DUP of cases in two areas of the city receiving early detection vs detection as usual, controlling for baseline DUP in each area.
Results
DUP in the intervention area was reduced from a median 71 days (mean 285) to 39 days (mean 104) following the intervention, with no change in the control area. Relative risk for the reduction in DUP was 0.74 (95 % CI 0.35 to 0.89; p = .004). Delays in MHSs and help-seeking were also reduced.
Conclusions
Our targeted approach appears to be successful in reducing DUP and could provide a generalizable methodology applicable in a variety of healthcare contexts with differing sources of delay. More research is needed, however, to establish whether our approach is truly effective
Ultra-wide-field retinal imaging in the management of non-infectious retinal vasculitis.
BACKGROUND: The purpose of this study is to describe and quantify the benefit of ultra-wide-field imaging and fluorescein angiography (FA) in the management of non-infectious retinal vasculitis. In this prospective observational cohort series, patients with non-infectious retinal vasculitis were evaluated and enrolled by four investigators from the Divisions of Retina and Ocular Immunology at the Wilmer Eye Institute. In each patient, disease activity and the need for management changes were assessed, based on clinical examination with or without standard (60°) imaging and then with the addition of ultra-wide-field pseudo-color scanning laser ophthalmoscope (SLO) images and FA using the Optos ultra-wide-field SLO (Optos Panoramic 200MA™, Optos PLC, Dunfermline, Scotland, UK). A standardized questionnaire was completed by each investigator at the time of the clinical evaluation.The primary outcome was the percentage of patients whose management was changed by clinical examination and standard FA, compared with clinical examination plus ultra-wide-field imaging. The secondary outcome was the percentage of patients whose disease was determined to be active based on each modality.
RESULTS: Seventy-one visits from 23 patients were reviewed and analyzed. Based on examination plus ultra-wide-field imaging and ultra-wide-field angiography, disease activity was detected in 48/71 (68%) compared with 32/71 (45%) based on examination and standard FA (P = 0.0095). Based on the clinical examination alone, the decision to alter management was made in 4 of 71 visits (6%), and an additional 3 of 71 (4%) based on simulated standard FA. The addition of ultra-wide-field SLO pseudo-color images altered management in an additional 10/71 visits (14%), and 36/71 (51%) with the addition of ultra-wide-field FA.
CONCLUSIONS: Ultra-wide-field fluorescein imaging and angiography can provide additional information that may be important and relevant in the management of retinal vasculitis
Determination of interatomic coupling between two-dimensional crystals using angle-resolved photoemission spectroscopy
Lack of directional bonding between two-dimensional crystals like graphene or
monolayer transition metal dichalcogenides provides unusual freedom in
selection of components for vertical van der Waals heterostructures. However,
even for identical layers, their stacking, in particular the relative angle
between their crystallographic directions, modifies properties of the
structure. We demonstrate that the interatomic coupling between two
two-dimensional crystals can be determined from angle-resolved photoemission
spectra of a trilayer structure with one aligned and one twisted interface.
Each of the interfaces provides complementary information and together they
enable self-consistent determination of the coupling. We parametrize
interatomic coupling for carbon atoms by studying twisted trilayer graphene and
show that the result can be applied to structures with different twists and
number of layers. Our approach demonstrates how to extract fundamental
information about interlayer coupling in a stack of two-dimensional crystals
and can be applied to many other van der Waals interfaces.Comment: This is a post-peer-review, pre-copyedit version of an article
published in Nature Communications. The final authenticated version is
available online at: http://dx.doi.org/10.1038/s41467-020-17412-
AntiJen: a quantitative immunology database integrating functional, thermodynamic, kinetic, biophysical, and cellular data
AntiJen is a database system focused on the integration of kinetic, thermodynamic, functional, and cellular data within the context of immunology and vaccinology. Compared to its progenitor JenPep, the interface has been completely rewritten and redesigned and now offers a wider variety of search methods, including a nucleotide and a peptide BLAST search. In terms of data archived, AntiJen has a richer and more complete breadth, depth, and scope, and this has seen the database increase to over 31,000 entries. AntiJen provides the most complete and up-to-date dataset of its kind. While AntiJen v2.0 retains a focus on both T cell and B cell epitopes, its greatest novelty is the archiving of continuous quantitative data on a variety of immunological molecular interactions. This includes thermodynamic and kinetic measures of peptide binding to TAP and the Major Histocompatibility Complex (MHC), peptide-MHC complexes binding to T cell receptors, antibodies binding to protein antigens and general immunological protein-protein interactions. The database also contains quantitative specificity data from position-specific peptide libraries and biophysical data, in the form of diffusion co-efficients and cell surface copy numbers, on MHCs and other immunological molecules. The uses of AntiJen include the design of vaccines and diagnostics, such as tetramers, and other laboratory reagents, as well as helping parameterize the bioinformatic or mathematical in silico modeling of the immune system. The database is accessible from the URL:
Don’t turn your back on the symptoms of psychosis : a proof-of-principle, quasi-experimental public health trial to reduce the duration of untreated psychosis in Birmingham, UK
Background: Reducing the duration of untreated psychosis (DUP) is an aspiration of international guidelines for first episode psychosis; however, public health initiatives have met with mixed results. Systematic reviews suggest that greater focus on the sources of delay within care pathways, (which will vary between healthcare settings) is needed to achieve sustainable reductions in DUP (BJP 198: 256-263; 2011).
Methods/Design: A quasi-experimental trial, comparing a targeted intervention area with a ‘detection as usual’ area in the same city. A proof-of–principle trial, no a priori assumptions are made regarding effect size; key outcome will be an estimate of the potential effect size for a definitive trial. DUP and number of new cases will be collected over an 18-month period in target and control areas and compared; historical data on DUP collected in both areas over the previous three years, will serve as a benchmark. The intervention will focus on reducing two significant DUP component delays within the overall care pathway: delays within the mental health service and help-seeking delay.
Discussion: This pragmatic trial will be the first to target known delays within the care pathway for those with a first episode of psychosis. If successful, this will provide a generalizable methodology that can be implemented in a variety of healthcare contexts with differing sources of delay.
Trial registration: http://www.controlled-trials.com/ISRCTN45058713
Keywords: Public mental health campaign, First-episode psychosis, Early detection, Duration of untreated psychosis, Youth mental healt
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