102 resultados para Clark, Orman
Resumo:
BACKGROUND:
The genetic heterogeneity of many Mendelian disorders, such as retinitis pigmentosa which results from mutations in over 40 genes, is a major obstacle to obtaining a molecular diagnosis in clinical practice. Targeted high-throughput DNA sequencing offers a potential solution and was used to develop a molecular diagnostic screen for patients with retinitis pigmentosa.
METHODS:
A custom sequence capture array was designed to target the coding regions of all known retinitis pigmentosa genes and used to enrich these sequences from DNA samples of five patients. Enriched DNA was subjected to high-throughput sequencing singly or in pools, and sequence variants were identified by alignment of up to 10 million reads per sample to the normal reference sequence. Potential pathogenicity was assessed by functional predictions and frequency in controls.
RESULTS AND CONCLUSIONS:
Known homozygous PDE6B and compound heterozygous CRB1 mutations were detected in two patients. A novel homozygous missense mutation (c.2957A?T; p.N986I) in the cyclic nucleotide gated channel ß1 (CNGB1) gene predicted to have a deleterious effect and absent in 720 control chromosomes was detected in one case in which conventional genetic screening had failed to detect mutations. The detection of known and novel retinitis pigmentosa mutations in this study establishes high-throughput DNA sequencing with DNA pooling as an effective diagnostic tool for heterogeneous genetic diseases.
Resumo:
The farm production of silage as a winter-feed supplement is widespread. However, the bins in which silage is produced are subject to acidic and microbial attacks. Both these types of attack can lead to a weakening and failure of the concretes, especially on the outer lip of the open side of the silage pit. Consequently, the development of an acid-resistant concrete that can extend the life span of silage bins on farms could lead to considerable cost savings for farmers and, hence, can improve farm productivity. This paper reports on test results of an investigation into the behaviour of concrete containing seawater-neutralised bauxite refinery residues (Bauxsol™) exposed to sulphuric acid environments in the laboratory and to silage effluents. The concrete manufactured had a fixed water–cement ratio of 0.55 and natural sand was replaced with the Bauxsol™ at 0%, 5%, 10%, 15% and 20% by cement mass. Results indicated that the use of Bauxsol™ as a sand replacement material improved the behaviour of concrete both in sulphuric acid in the laboratory as well as in the silage effluent. Consequently, it is concluded that the Bauxsol™ can be used to replace 10% of natural sand to produce concrete that is resistant to silage effluents, providing an extended service life over conventional concretes used in silage pits.
Resumo:
Background: The main aims of the study were to assess psychological morbidity among adults nine months after a car bomb explosion in the town of Omagh, Northern Ireland and to identify predictors of chronic posttraumatic stress disorder symptoms.
Method: A questionnaire was sent to all adults in households in The Omagh District Council area. The questionnaire comprised established predictors of PTSD (such as pre-trauma personal characteristics, type of exposure, initial emotional response and long-term adverse physical or financial problems), predictors derived from the Ehlers and Clark (2000) cognitive model, a measure of PTSD symptoms and the General Health Questionnaire.
Results: Among respondents (n = 3131) the highest rates of PTSD symptoms and probable casesness (58.5%) were observed among people who were present in the street when the bomb exploded but elevated rates were also observed in people who subsequently attended the scene (21.8% probable caseness) and among people for whom someone close died (11.9%). People with a near miss (left the scene before the explosion) did not show elevated rates. Exposure to the bombing increased PTSD symptoms to a greater extent than general psychiatric symptoms. Previously established predictors accounted for 42% of the variance in PTSD symptoms among people directly exposed to the bombing. Predictors derived from the cognitive model accounted for 63%.
Conclusions: High rates of chronic PTSD were observed in individuals exposed to the bombing. Psychological variables that are in principle amenable to treatment were the best predictors of PTSD symptoms. Teams planning treatment interventions for victims of future bombings and other traumas may wish to take these results into account.
Resumo:
The expansion of electromagnetic postsolitons emerging from the interaction of a 30 ps, 3 x 10(18) W cm(-2) laser pulse with an underdense deuterium plasma has been observed up to 100 ps after the pulse propagation, when large numbers of postsolitons were seen to remain in the plasma. The temporal evolution of the postsolitons has been accurately characterized with a high spatial and temporal resolution. The observed expansion is compared to analytical models and three-dimensional particle-in-cell results, revealing a polarization dependence of the postsoliton dynamics.
Resumo:
The experimental study of the behavior of deuterium plasma with densities between 2 X 1018 and 2 x 10(20) cm(-3), subjected to a 6 TW, 30 ps, 3 X 10(18) W cm(-2) laser pulse, is presented Conclusive experimental proof that a single straight channel is generated when the laser pulse interacts with the lowest densities is provided This channel shows no small-scale longitudinal density modulations, extends up to 2 mm in length and persists for up to 150 ps after the peak of the interaction Bifurcation of the channel after 1 mm propagation distance is observed for the first time For higher density interactions, above the relativistic self-focusing threshold, bubblelike structures are observed to form at late times These observations have implications for both laser wakefield accelerators and fast ignition inertial fusion studies (C) 2010 American Institute of Physics [doi 10 1063/1 3505305]
Resumo:
Various industrial by-products, such as fly ash, ground granulated blast-furnace slag and silica fume, have been used in concrete to improve its properties. This also enables any environmental issues associated with their disposal. Another material that is available in large quantities and requiring alternative methods of disposal is the Bauxite Refinery Reside (BRR) from the Bayer process used to extract alumina from bauxite. As this is highly caustic and causes many health hazards, Virotec International Ltd. developed a patented technology to convert this into a material that can be used commercially, known as Bauxsol™, for various environmental remediation applications. This use is limited to small quantities of seawater-neutralised BRR and hence an investigation was carried out to establish its potential utilisation as a sand replacement material in concrete. In addition to fresh properties of concrete containing seawater-neutralised BRR up to 20% by mass of Portland cement, mechanical and durability properties were determined. These properties indicated that seawater-neutralised BRR can be used to replace natural sand up to 10% by mass of cement to improve the durability properties of concrete without detrimentally affecting their physical properties. Combining these beneficial effects with environmental remediation applications, it can be concluded that there are specific applications where concretes containing seawater-neutralised BRR could be used.
Resumo:
Purpose. The effects of an integrated medicines management (IMM) program on medication appropriateness are discussed.
Resumo:
This paper presents the results of an experimental investigation carried out to evaluate the influence of Bauxsol, an artificially neutralised bauxite refinery residue (NBRR), on various properties of cement pastes. It was found that the NBRR does not have any pozzolanic properties and hence cannot be used as a supplementary cementitious material in concrete. In order to evaluate the effect of adding the product to Portland cement (PC) pastes, fresh properties (i.e. standard consistency and slump), setting time and heat of hydration were measured. In addition, its influence on chemical changes and compressive strength was investigated. It was found that the addition of this NBRR resulted in a decrease in compressive strength beyond 7 days. The setting time decreased with an increase in NBRR content in PC pastes. The rate of heat evolution for NBRR pastes was greater than that of the PC pastes, but a corresponding increase in the quantity of calcium hydroxide was not found. Therefore, it was concluded that unidentified hydration products when Bauxsol was used in PC pastes might have been the reason for the decrease in setting times.
Resumo:
Cognitive models of posttraumatic stress disorder (PTSD) assert that memory processes play a significant role in PTSD (see e.g., Ehlers & Clark, 2000). Intrusive reexperiencing in PTSD has been linked to perceptual processing of trauma-related material with a corresponding hypothesized lack of conceptual processing. In an experimental study that included clinical participants with and without PTSD (N = 50), perceptual priming and conceptual priming for trauma-related, general threat, and neutral words were investigated in a population with chronic trauma-induced complaints as a result of the Troubles in Northern Ireland. The study used a new version of the word-stem completion task (Michael, Ehlers, & Halligan, 2005) and a word-cue association task. It also assessed the role of dissociation in threat processing. Further evidence of enhanced perceptual priming in PTSD for trauma stimuli was found, along with evidence of lack of conceptual priming for such stimuli. Furthermore, this pattern of priming for trauma-related words was associated with PTSD severity, and state dissociation and PTSD group made significant contributions to predicting perceptual priming for trauma words. The findings shed light on the importance of state dissociation in trauma-related information processing and posttraumatic symptoms.
Resumo:
The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our scientific motivations and give an overview of the survey targets, including optical and near-infrared photometry and comprehensive details of the data reduction. One of the principal objectives was to detect massive binary systems via variations in their radial velocities, thus shaping the multi-epoch observing strategy. Spectral classifications are given for the massive emission-line stars observed by the survey, including the discovery of a new Wolf-Rayet star (VFTS 682, classified as WN5h), 2' to the northeast of R136. To illustrate the diversity of objects encompassed by the survey, we investigate the spectral properties of sixteen targets identified by Gruendl & Chu from Spitzer photometry as candidate young stellar objects or stars with notable mid-infrared excesses. Detailed spectral classification and quantitative analysis of the O- and B-type stars in the VFTS sample, paying particular attention to the effects of rotational mixing and binarity, will be presented in a series of future articles to address fundamental questions in both stellar and cluster evolution.
Resumo:
Democracies are faced increasingly with the challenge of engaging the public on the assumption that such activity will lead to greater understanding of, and enhanced trust in, political institutions. This is a particular difficulty for an institution such as the Northern Ireland Assembly (NIA), established against the backdrop of a historically divided society with high levels of political conflict and which has itself been suspended on several occasions. This article reports the findings from the NIA's first survey of public engagement, conducted as part of the Assembly's broader engagement strategy. It provides a baseline against which future levels of engagement can be judged. Moreover, it highlights a range of challenges that face both the NIA and its Members of the Legislative Assembly if the Assembly is to engage successfully with the public in the aftermath of the 2011 elections.