1,708 research outputs found
Cryogenic and room temperature strength of sapphire jointed by hydroxide-catalysis bonding
Hydroxide-catalysis bonding is a precision technique used for jointing components in opto-mechanical systems and has been implemented in the construction of quasi-monolithic silica suspensions in gravitational wave detectors. Future detectors are likely to operate at cryogenic temperatures which will lead to a change in test mass and suspension material. One candidate material is mono-crystalline sapphire. Here results are presented showing the influence of various bonding solutions on the strength of the hydroxide-catalysis bonds formed between sapphire samples, measured both at room temperature and at 77 K, and it is demonstrated that sodium silicate solution is the most promising in terms of strength, producing bonds with a mean strength of 63 MPa. In addition the results show that the strengths of bonds were undiminished when tested at cryogenic temperatures
Safety and immunogenicity of a new tuberculosis vaccine, MVA85A, in mycobacterium tuberculosis–infected individuals
Copyright © 2009 by the American Thoracic Society.Rationale: An effective new tuberculosis (TB) vaccine regimen must be safe in individuals with latent TB infection (LTBI) and is a priority for global health care.
Objectives: To evaluate the safety and immunogenicity of a leading new TB vaccine, recombinant Modified Vaccinia Ankara expressing Antigen 85A (MVA85A) in individuals with LTBI.
Methods: An open-label, phase I trial of MVA85A was performed in 12 subjects with LTBI recruited from TB contact clinics in Oxford and London or by poster advertisements in Oxford hospitals. Patients were assessed clinically and had blood samples drawn for immunological analysis over a 52-week period after vaccination with MVA85A. Thoracic computed tomography scans were performed at baseline and at 10 weeks after vaccination. Safety of MVA85A was assessed by clinical, radiological, and inflammatory markers. The immunogenicity of MVA85A was assessed by IFNγ and IL-2 ELISpot assays and FACS.
Measurements and Main Results: MVA85A was safe in subjects with LTBI, with comparable adverse events to previous trials of MVA85A. There were no clinically significant changes in inflammatory markers or thoracic computed tomography scans after vaccination. MVA85A induced a strong antigen-specific IFN-γ and IL-2 response that was durable for 52 weeks. The magnitude of IFN-γ response was comparable to previous trials of MVA85A in bacillus Calmette-Guérin–vaccinated individuals. Antigen 85A–specific polyfunctional CD4+ T cells were detectable prior to vaccination with statistically significant increases in cell numbers after vaccination.
Conclusions: MVA85A is safe and highly immunogenic in individuals with LTBI. These results will facilitate further trials in TB-endemic areas.Oxford Biomedical Research Centre, Wellcome Trust, and AFTBVAC
Health-services utilisation amongst older persons during the last year of life: A population-based study
© 2018 The Author(s). Background: Accurate population-based data regarding hospital-based care utilisation by older persons during their last year of life are important in health services planning. We investigated patterns of acute hospital-based service use at the end of life, amongst older decedents in New South Wales (NSW), Australia. Methods: Data from all persons aged ≥70 years who died in the state of NSW Australia in 2007 were included. Several measures of hospital-based service utilisation during the last year of life were assessed from retrospectively linked data comprising data for all registered deaths, cause of death, hospital care during the last year of life (NSW Admitted Patient Data Collection [APDC] and Emergency Department [ED] Data Collection [EDDC]), and the NSW Cancer Registry. Results: Amongst 34,556 decedents aged ≥70 years, 82% (n = 28,366) had ≥1 hospitalisation during the last year of life (median 2), and 21% > 3 hospitalisations. Twenty-five percent (n = 5485) of decedents attended ED during the last week of life. Overall, 21% had a hospitalisation > 30 days in the last year of life, and 7% spent > 3 months in hospital; 79% had ≥1 ED attendance, 17% > 3. Nine percent (n = 3239) spent time in an intensive care unit. Fifty-three percent (n = 18,437) died in an inpatient setting. Hospital records had referenced palliative care for a fifth (7169) of decedents. Adjusting for age group, sex, place of residence, area-level socioeconomic status, and cause of death, having > 3 hospitalisations during the last year of life was more likely for persons dying from cancer (35% versus 16% non-cancer deaths, adjusted odds ratio [aOR] 2.33), 'younger' old decedents (29% for age 70-79 and 20% for age 80-89 versus 11% for 90+, aOR 2.42 and 1.77 respectively) and males (25% versus 17% females, aOR 1.38). Patterns observed for other hospital-based service use were similar. Conclusions: This population-based study reveals high use of hospital care among older persons during their last year of life, although this decreased with increasing older age, providing important data to inform health services planning for this population, and highlighting aspects requiring further study
An epidemiological study of a patient population, triage category allocations and principal diagnosis within the emergency centres of a private healthcare group in the Emirate of Dubai, United Arab Emirates
Aim: To describe, compare and correlate the number of patients seen, their demographics, triage category allocations and principal diagnosis in four emergency centres; to better understand the patient population and triage practices in this setting. Design: An observational, cross-sectional, epidemiological study. Methods: Electronic medical records were retrospectively evaluated from patients triaged in each of the four emergency centres over six months. Descriptive statistics were used to describe the patient demographics and variance between triage category allocations. Results: A total of 56,984 patient records were captured, with an equal gender split and the workforce being the largest patient population (20–50 years). Acute upper respiratory infection was the most prolific diagnosis, and lower acuity triage categories were allocated the most. There were inconsistencies in the application of triage systems between the emergency centres, the most obvious being the variance in triage system selection and application
Analyses of mitochondrial amino acid sequence datasets support the proposal that specimens of Hypodontus macropi from three species of macropodid hosts represent distinct species
Background: Hypodontus macropi is a common intestinal nematode of a range of kangaroos and wallabies
(macropodid marsupials). Based on previous multilocus enzyme electrophoresis (MEE) and nuclear ribosomal DNA
sequence data sets, H. macropi has been proposed to be complex of species. To test this proposal using
independent molecular data, we sequenced the whole mitochondrial (mt) genomes of individuals of H. macropi
from three different species of hosts (Macropus robustus robustus, Thylogale billardierii and Macropus [Wallabia]
bicolor) as well as that of Macropicola ocydromi (a related nematode), and undertook a comparative analysis of the
amino acid sequence datasets derived from these genomes.
Results: The mt genomes sequenced by next-generation (454) technology from H. macropi from the three host
species varied from 13,634 bp to 13,699 bp in size. Pairwise comparisons of the amino acid sequences predicted
from these three mt genomes revealed differences of 5.8% to 18%. Phylogenetic analysis of the amino acid
sequence data sets using Bayesian Inference (BI) showed that H. macropi from the three different host species
formed distinct, well-supported clades. In addition, sliding window analysis of the mt genomes defined variable
regions for future population genetic studies of H. macropi in different macropodid hosts and geographical regions
around Australia.
Conclusions: The present analyses of inferred mt protein sequence datasets clearly supported the hypothesis that
H. macropi from M. robustus robustus, M. bicolor and T. billardierii represent distinct species.© 2013 Jabbar et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited
Microalgae production in fresh market wastewater and its utilization as a protein substitute in formulated fish feed for oreochromis spp.
Rapid growing of human population has led to increasing demand of aquaculture production. Oreochromis niloticus or known as tilapia is one of the most globally cultured freshwater fish due to its great adaptation towards extreme environment. Besides, farming of tilapia not only involves small scales farming for local consumption but also larger scales for international market which contributes to a foreign currency earning. Extensive use of fishmeal as feed for fish and for other animals indirectly caused an increasing depletion of the natural resource and may consequently cause economic and environmental unstable. Microalgae biomass seems to be a promising feedstock in aquaculture industry. It can be used for many purposes such as live food for fish larvae and dried microalgae to substitute protein material in fish feed. The microalgae replacement in fish feed formulation as protein alternative seem potentially beneficial for long term aqua-business sustainability. The present chapter discussed the potential of microalgae as an alternative nutrition in fish feed formulations, specifically Tilapia
Feline parvovirus seroprevalence is high in domestic cats from disease outbreak and non‐outbreak regions in Australia
Multiple, epizootic outbreaks of feline panleukopenia (FPL) caused by feline parvovirus (FPV) occurred in eastern Australia between 2014 and 2018. Most affected cats were unvaccinated. We hypothesised that low population immunity was a major driver of re‐emergent FPL. The aim of this study was to (i) determine the prevalence and predictors of seroprotective titres to FPV among shelter‐housed and owned cats, and (ii) compare the prevalence of seroprotection between a region affected and unaffected by FPL outbreaks. FPV antibodies were detected by haemagglutination inhibition assay on sera from 523 cats and titres ≥1:40 were considered protective. Socioeconomic indices based on postcode and census data were included in the risk factor analysis. The prevalence of protective FPV antibody titres was high overall (94.3%), even though only 42% of cats were known to be vaccinated, and was not significantly different between outbreak and non‐outbreak regions. On multivariable logistic regression analysis vaccinated cats were 29.94 times more likely to have protective FPV titres than cats not known to be vaccinated. Cats from postcodes of relatively less socioeconomic disadvantage were 5.93 times more likely to have protective FPV titres. The predictors identified for FPV seroprotective titres indicate targeted vaccination strategies in regions of socioeconomic disadvantage would be beneficial to increase population immunity. The critical level of vaccine coverage required to halt FPV transmission and prevent FPL outbreaks should be determined
Spiral valve parasites of blue and common thresher sharks as indicators of shark feeding behaviour and ecology
Open Access via the Jisc Wiley agreement Acknowledgements This work would not have been possible without the assistance and samples provided by the National Marine Fisheries Service (NMFS) Southwest Region Fishery Observer Program and the participating drift gillnet fishermen. A. Arevalo, E. Reed, H. Colley, J. Williams, J. Tamez and K. Tran assisted with spiral valve dissections and parasite sorting in the lab. D. Losey helped with library research. D. Sweetnam, A. Yau, A. Thompson, M. Craig, S. Stohs, G. DiNardo provided constructive critiques that helped improve the manuscript. This research was supported by the National Oceanographic Atmospheric Administration (NOAA).Peer reviewedPublisher PD
Theory of excited state absorptions in phenylene-based -conjugated polymers
Within a rigid-band correlated electron model for oligomers of
poly-(paraphenylene) (PPP) and poly-(paraphenylenevinylene) (PPV), we show that
there exist two fundamentally different classes of two-photon A states in
these systems to which photoinduced absorption (PA) can occur. At relatively
lower energies there occur A states which are superpositions of one
electron - one hole (1e--1h) and two electron -- two hole (2e--2h) excitations,
that are both comprised of the highest delocalized valence band and the lowest
delocalized conduction band states only. The dominant PA is to one specific
member of this class of states (the mA). In addition to the above class of
A states, PA can also occur to a higher energy kA state whose 2e--2h
component is {\em different} and has significant contributions from excitations
involving both delocalized and localized bands. Our calculated scaled energies
of the mA and the kA agree reasonably well to the experimentally
observed low and high energy PAs in PPV. The calculated relative intensities of
the two PAs are also in qualitative agreement with experiment. In the case of
ladder-type PPP and its oligomers, we predict from our theoretical work a new
intense PA at an energy considerably lower than the region where PA have been
observed currently. Based on earlier work that showed that efficient
charge--carrier generation occurs upon excitation to odd--parity states that
involve both delocalized and localized bands, we speculate that it is the
characteristic electronic nature of the kA that leads to charge generation
subsequent to excitation to this state, as found experimentally.Comment: Revtex4 style, 2 figures inserted in the text, three tables, 10 page
Sensitivity Studies for Third-Generation Gravitational Wave Observatories
Advanced gravitational wave detectors, currently under construction, are
expected to directly observe gravitational wave signals of astrophysical
origin. The Einstein Telescope, a third-generation gravitational wave detector,
has been proposed in order to fully open up the emerging field of gravitational
wave astronomy. In this article we describe sensitivity models for the Einstein
Telescope and investigate potential limits imposed by fundamental noise
sources. A special focus is set on evaluating the frequency band below 10Hz
where a complex mixture of seismic, gravity gradient, suspension thermal and
radiation pressure noise dominates. We develop the most accurate sensitivity
model, referred to as ET-D, for a third-generation detector so far, including
the most relevant fundamental noise contributions.Comment: 13 pages, 7 picture
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