973 resultados para Cent.


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Introduction and Aims: Previous studies have shown that the lungs of Cystic Fibrosis (CF) and bronchiectasis (BE, not caused by CF) patients are colonised by a range of aerobic and anaerobic bacteria. As bacteria are also implicated in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD), this study aimed to determine the culture microbiome of the COPD airways.

Methods: Samples were collected from 13 stable COPD patients during routine bronchoscopy. Bronchial washings were taken at a single location in the right middle lobe by flushing and removing 30 ml of sterile saline. Samples were cultured under strict anaerobic conditions with bacteria detected by plating on both selective and non-selective agar media and quantified by total viable count (TVC). Identification of the cultured bacteria was performed by amplification and subsequent sequencing of the 16sRNA gene.

Results: Mean FEV1 was 1.36 (range 0.84–2.26, mean per cent predicted FEV1, 54%), and the mean ratio (FEV1/FVC) was 51%. Bacteria were detected in 12/13 samples (92%) with bacteria from the genera Streptococcus [12/13 samples, 92%; mean (range) TVC 9.62×105 cfu/ml (1.50×103–1.42×107)] and Haemophilus [4/13 samples, 31%; mean (range) 6.40×104 cfu/ml (2.20×103–1.60×105)] most frequently detected. Anaerobic bacteria primarily from the genera Prevotella [8/13 samples, 62%; mean (range) TVC 1.12×104 cfu/ml (1.30×103–4.20×104)] and Veillonella [5/13 samples, 38%; mean (range) TVC 1.29×105 cfu/ml (4.20×103–3.60×105)] were also detected. Pseudomonas and Moraxella were not detected in any samples.

Conclusions: Our results show that bacteria from the genera Streptococcus, Haemophilus, Prevotella and Veillonella are frequently present the airways of patients suffering from COPD. Taking account of the dilutional effect of the bronchial wash procedure and extrapolating to allow comparison with sputum data in our laboratory for CF and BE, the relative load of bacteria from the genera Streptococcus, Prevotella and Veillonella is similar in these three airway diseases. The potential role of these bacteria in the progression and pathogenesis of COPD requires further investigation.

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INTRODUCTION: Vocational training (VT) is a mandatory 12 month period for UK dental graduates after graduation. Graduates of Irish Dental Schools are eligible to enter the general dental service in Ireland or obtain an NHS performers list number in the UK immediately after qualification. Reports would suggest that some graduates of Irish Dental Schools are choosing to take part in VT in the UK and find the experience beneficial. This study aimed to record the uptake of VT amongst recent graduates from University College Cork and to document their experiences. It was designed to compare the attitudes and experiences of graduates of Irish Dental Schools who undertook VT compared with those who entered the general dental service.

METHOD: A self-completion questionnaire was distributed by e-mail to dental graduates from University College Cork who had graduated 2001-2007. Responses were returned by e-mail or post.

RESULTS: The response rate was 68.9%. There has been an increase in the numbers of graduates taking part in VT each year since 2004. 92.5% of Vocational Dental Practitioners (VDPs) found their experience beneficial as they received a guaranteed source of income, had a supportive peer network and worked in a positive learning environment. However, some felt that they earned a lower income than their associate colleagues, others found the pace of practice slow and that the duration of the training period was excessive. Eighty-five per cent of VDPs would choose the same position again after graduation as compared with 61.8% of associates (P < 0.001). Ninety per cent of VDPs would advise current undergraduates to take part in VT as compared with 51% of associates (P < 0.001). A larger proportion of VDPs had taken part in postgraduate studies but there was no significant difference between the two groups.

CONCLUSIONS: Larger proportions of recent graduates are undertaking vocational training.--The majority of VDPs and associates find their initial employment position beneficial.--VDPs benefit from a guaranteed source of income, a supportive peer network and a positive learning environment.--Some associates suffered from a lack of support, feeling isolated and overwhelmed with patients.--The majority of previous VDPs and associates would recommend VT to current undergraduates.--Almost 40% of associates would now choose to take part in VT if given the opportunity.

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INTRODUCTION: Intravenous sedation is the most commonly used method of sedation for the provision of adult dental care. However, disparity exists in pre-operative fasting times in use for patients throughout the United Kingdom.

AIMS: The aims of the study were to obtain information on the effects of existing extended pre-operative fasting regimens, to canvas patient opinions on the fasting process, and to record their positive and negative experiences associated with it.

METHODS: A prospective cross-sectional descriptive study using survey methodology was conducted of adult patients attending a dental hospital for operative treatment under intravenous sedation. Sixty-four questionnaires were distributed over a four-month period, beginning 2nd October 2007.

RESULTS: The surveyed patient pool consisted of 38 females and 14 males with a mean age of 32.4 years. The response rate achieved was 81.2%. Seventy-one per cent of patients indicated that normally they consumed something for breakfast, the most common items being tea and toast. Fifty-one per cent of patients indicated that they would wish to eat the same as normal prior to their appointment and 59% wished to drink as normal. Only 19% of respondents reported that they did not wish to eat anything, with 8% preferring not to drink anything at all. Seventy-nine per cent of the patients reported that they had experienced at least one adverse symptom after fasting and 42% had experienced two or more such symptoms. In general, those patients with more experience of sedation found fasting less unpleasant than those attending for the first time (P<0.05). In addition, one-quarter of all patients indicated that the fasting process had made them feel more nervous about their sedation appointment.

CONCLUSIONS: The extended fasting regimen prior to intravenous sedation appeared to affect patients' wellbeing, as the majority reported adverse symptoms.

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An ultra-relativistic electron beam passing through a thick, high-Z solid target triggers an electromagnetic cascade, whereby a large number of high energy photons and electron-positron pairs are produced. By exploiting this physical process, we present here the first experimental evidence of the generation of ultra-short, highly collimated and ultra-relativistic positron beams following the interaction of a laser-wake field accelerated electron beam with high-Z solid targets. Clear evidence has also been obtained of the generation of GeV electron-positron jets with variable composition depending on the solid target material and thickness. The percentage of positrons in the overall leptonic beam has been observed to vary from a few per cent up to almost fifty per cent, implying a quasi-neutral electron-positron beam. We anticipate that these beams will be of direct relevance to the laboratory study of astrophysical leptonic jets and their interaction with the interstellar medium.

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The reported incidence of gastrointestinal endocrine tumours is variable. In Northern Ireland circumstances allowing such an assessment are favourable with a central diagnostic laboratory and register established to collect data on tumours from a well-defined population of 1.5 million people. From 1970 to 1985, 368 cases were recorded of which 85 per cent were carcinoid tumours. The annual incidence of carcinoid tumours was 1.3 per 100,000 of the population and the majority occurred in the appendix (61 per cent). No patients presented with the carcinoid syndrome. The annual incidence for other tumours was 0.12 per 100,000 for insulinomas; islet cell tumours of unknown type 0.07; Zollinger-Ellison syndrome 0.05; and multiple endocrine neoplasia (MEN) 0.05. There were two cases of VIPoma, one glucagonoma, one neurotensinoma and one tumour producing ACTH. It is possible that some tumours are more uncommon than others because of difficulty in diagnosis.

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There has been little assessment of the role the MDGs have had in progressing international development. There has been a 41 per cent reduction in the under-5 mortality rate worldwide from 1990 to 2011 and an acceleration in the rate of reduction since 2000. This paper explores why this has occurred and results for all developing countries indicate that it is not due to more healthcare or public health interventions but is driven by a coincidental burst of economic growth. Although the MDGs are considered to have played an important part in securing progress against poverty, hunger and disease there is very little evidence to back this viewpoint up. A thorough analysis of the successes and failures of the MDGs is therefore necessary before embarking on a new round of global goals.

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Efficient identification and follow-up of astronomical transients is hindered by the need for humans to manually select promising candidates from data streams that contain many false positives. These artefacts arise in the difference images that are produced by most major ground-based time-domain surveys with large format CCD cameras. This dependence on humans to reject bogus detections is unsustainable for next generation all-sky surveys and significant effort is now being invested to solve the problem computationally. In this paper, we explore a simple machine learning approach to real-bogus classification by constructing a training set from the image data of similar to 32 000 real astrophysical transients and bogus detections from the Pan-STARRS1 Medium Deep Survey. We derive our feature representation from the pixel intensity values of a 20 x 20 pixel stamp around the centre of the candidates. This differs from previous work in that it works directly on the pixels rather than catalogued domain knowledge for feature design or selection. Three machine learning algorithms are trained (artificial neural networks, support vector machines and random forests) and their performances are tested on a held-out subset of 25 per cent of the training data. We find the best results from the random forest classifier and demonstrate that by accepting a false positive rate of 1 per cent, the classifier initially suggests a missed detection rate of around 10 per cent. However, we also find that a combination of bright star variability, nuclear transients and uncertainty in human labelling means that our best estimate of the missed detection rate is approximately 6 per cent.

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Energy levels, radiative rates and lifetimes are calculated among the lowest 98 levels of the n ≤4 configurations of Be-like Al X. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted and data are provided for all E1, E2, M1 and M2 transitions. Similar data are also obtained with the FAC (Flexible Atomic Code) to assess the accuracy of the calculations. Based on comparisons between calculations with the two codes as well as with available measurements, our listed energy levels are assessed to be accurate to better than 0.3 per cent. However, the accuracy for radiative rates and lifetimes is estimated to be about 20 per cent. Collision strengths are also calculated for which the DARC (Dirac Atomic R-matrix Code) is used. A wide energy range (up to 380 Ryd) is considered and resonances resolved in a fine energy mesh in the thresholds region. The collision strengths are subsequently averaged over a Maxwellian velocity distribution to determine effective collision strengths up to a temperature of 1.6 × 107 K. Our results are compared with the previous (limited) atomic data and significant differences (up to a factor of 4) are noted for several transitions, particularly those which are not allowed in jj coupling. 

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High spectral resolution (~80 000) and signal-to-noise observations from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project (UVES-POP) are used to study the interstellarmolecular lines CN (3874 Å), CH+ (3957, 4232 Å) and CH (3886, 4300 Å) towards 74 O- and B-type stellar sightlines. Additionally, archive data are presented for 140 ELODIE early-type stellar sightlines at R = 42 000, plus 25 FEROS at R = 48 000 and 3 UVES at R > 50 000, mainly in the CH+ (4232 Å) and CH (3886, 4300 Å) transitions. Detection rates are ~45 per cent for CN and ~67 per cent for the other lines in the POP sample, and ~10-15 per cent for CH+ and CH lines in the additional sample. CH and CH+ are well correlated between log[N(CH) cm-2]~12-14, implying that these clouds are CH+-like CH and not CN-like CH. CH is also very well correlated with Na I D in the range log[N(Na I cm-2]) ~12.2-14.2. A few sightlines show tentative velocity shifts of ~2 km s-1 between CH and CH+, which appear to be caused by differences in component strength in blends, and hence do not provide firm evidence for shocks. Finally, we describe a search for 13CH+ in a sightline towards HD 76341. No 13CH+ is detected, placing a limit on the 13CH+ to 12CH+ ratio of ~0.01. If a formal fit is attempted, the equivalent width ratio in the two isotopes is a factor ~90 but with large errors. 

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Energies for the lowest 56 levels, belonging to the 3s2 3p, 3s 3p2, 3p3, 3s2 3d, 3s 3p 3d, 3s2 4ℓ and 3s2 5ℓ configurations of Si II, are calculated using the General-purpose Relativistic Atomic Structure Package (GRASP) code. Analogous calculations have also been performed (for up to 175 levels) using the FlexibleAtomicCode (FAC). Furthermore, radiative rates are calculated for all E1, E2, M1 and M2 transitions. Extensive comparisons are made with available theoretical and experimental energy levels, and the accuracy of the present results is assessed to be better than 0.1Ryd. Similarly, the accuracy for radiative rates (and subsequently lifetimes) is estimated to be better than 20 per cent for most of the (strong) transitions. Electron impact excitation collision strengths are also calculated, with the Dirac Atomic R-matrix Code (DARC), over a wide energy range up to 13 Ryd. Finally, to determine effective collision strengths, resonances are resolved in a fine energy mesh in the thresholds region. These collision strengths are averaged over a Maxwellian velocity distribution and results listed over a wide range of temperatures, up to 105.5 K. Our data are compared with earlier R-matrix calculations and differences noted, up to a factor of 2, for several transitions. Although scope remains for improvement, the accuracy for our results of collision strengths and effective collision strengths is assessed to be about 20 per cent for a majority of transitions. 

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We report energy levels, radiative rates (A-values) and lifetimes for the astrophysically important Be-like ion C III. For the calculations, 166 levels belonging to the n ≤ 5 configurations are considered and the GRASP (General-purpose Relativistic Atomic Structure Package) is adopted. Einstein A-coefficients are provided for all E1, E2, M1 and M2 transitions, while lifetimes are compared with available measurements as well as theoretical results, and no large discrepancies noted. Our energy levels are assessed to be accurate to better than 1 per cent for a majority of levels, and A-values to better than 20 per cent for most transitions. Collision strengths are also calculated, for which the Dirac Atomic R-matrix Code (DARC) is used. A wide energy range, up to 21 Ryd, is considered and resonances resolved in a fine energy mesh in the thresholds region. The collision strengths are subsequently averaged over a Maxwellian velocity distribution to determine effective collision strengths up to a temperature of 8.0 ×10[5]K, sufficient for most astrophysical applications. Our data are compared with the recent R-matrix calculations of Fernández-Menchero et al., and significant differences (up to over an order of magnitude) are noted for several transitions over the complete temperature range of the results.

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We employ Ca II K and Na I D interstellar absorption-line spectroscopy of early-type stars in the Large and Small Magellanic Clouds (LMC, SMC) to investigate the large- and small-scale structure in foreground intermediate- and high-velocity clouds (I/HVCs). Data include FLAMES-GIRAFFE Ca II K observations of 403 stars in four open clusters, plus FEROS or UVES spectra of 156 stars in the LMC and SMC. The FLAMES observations are amongst the most extensive probes to date of Ca II structures on ∼20 arcsec scales in Magellanic I/HVCs. From the FLAMES data within a 0 ∘.∘.∘.5 field of view, the Ca II K equivalent width in the I/HVC components towards three clusters varies by factors of ≥10. There are no detections of molecular gas in absorption at intermediate or high velocities, although molecular absorption is present at LMC and Galactic velocities towards some sightlines. The FEROS/UVES data show Ca II K I/HVC absorption in ∼60 per cent of sightlines. The range in the Ca II/Na I ratio in I/HVCs is from –0.45 to +1.5 dex, similar to previous measurements for I/HVCs. In 10 sightlines we find Ca II/O I ratios in I/HVC gas ranging from 0.2 to 1.5 dex below the solar value, indicating either dust or ionization effects. In nine sightlines I/HVC gas is detected in both H I and Ca II at similar velocities, implying that the two elements form part of the same structure.

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Stellar evolution models predict the existence of hybrid white dwarfs (WDs) with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born with masses similar to 1.1 M-aS (TM), hybrid WDs in a binary system may easily approach the Chandrasekhar mass (M-Ch) by accretion and give rise to a thermonuclear explosion. Here, we investigate an off-centre deflagration in a near-M-Ch hybrid WD under the assumption that nuclear burning only occurs in carbon-rich material. Performing hydrodynamics simulations of the explosion and detailed nucleosynthesis post-processing calculations, we find that only 0.014 M-aS (TM) of material is ejected while the remainder of the mass stays bound. The ejecta consist predominantly of iron-group elements, O, C, Si and S. We also calculate synthetic observables for our model and find reasonable agreement with the faint Type Iax SN 2008ha. This shows for the first time that deflagrations in near-M-Ch WDs can in principle explain the observed diversity of Type Iax supernovae. Leaving behind a near-M-Ch bound remnant opens the possibility for recurrent explosions or a subsequent accretion-induced collapse in faint Type Iax SNe, if further accretion episodes occur. From binary population synthesis calculations, we find the rate of hybrid WDs approaching M-Ch to be of the order of 1 per cent of the Galactic SN Ia rate.

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AIMS: To determine the incidence and predictive factors of rib fracture and chest wall pain after lung stereotactic ablative radiotherapy (SABR).

MATERIALS AND METHODS: Patients were treated with lung SABR of 48-60 Gy in four to five fractions. The treatment plan and follow-up computed tomography scans of 289 tumours in 239 patients were reviewed. Dose-volume histogram (DVH) metrics and clinical factors were evaluated as potential predictors of chest wall toxicity.

RESULTS: The median follow-up was 21.0 months (range 6.2-52.1). Seventeen per cent (50/289) developed a rib fracture, 44% (22/50) were symptomatic; the median time to fracture was 16.4 months. On univariate analysis, female gender, osteoporosis, tumours adjacent (within 5 mm) to the chest wall and all of the chest wall DVH metrics predicted for rib fracture, but only tumour location adjacent to the chest wall remained significant on the multivariate model (P < 0.01). The 2 year fracture-free probability for those adjacent to the chest wall was 65.6%. Among those tumours adjacent to the chest wall, only osteoporosis (P = 0.02) predicted for fracture, whereas none of the chest wall DVH metrics were predictive. Eight per cent (24/289) experienced chest wall pain without fracture.

CONCLUSIONS: None of the chest wall DVH metrics independently predicted for SABR-induced rib fracture when tumour location is taken into account. Patients with tumours adjacent (within 5 mm) to the chest wall are at greater risk of rib fracture after lung SABR, and among these, an additional risk was observed in osteoporotic patients.

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A Gendered Profession, RIBA Publications, Oct 2016

For a profession that claims to be so concerned with the needs of society, the continuing gender imbalance in architectural education and practice is a difficult subject. Difficult, because it’s been stagnant for some thirty years. This book seeks to change that.
Beyond the profession, the emergence of fourth wave feminism has broken a twenty-year drought in the discourse[1]. A new generation of feminist critique is emerging, characterised by a broader civic commitment, one fuelled by the recognition that time and again, women and minorities have been the first casualties of neo-liberalism.
Whereas after World War II the architectural profession rallied around its obligation to fulfil a social need, today architecture has all but capitulated its absolute servitude to capitalism. Recognising that feminist thinking is a meaningful response to the inequalities of capitalism, A Gendered Profession will be a forum for a discussion about the failure of our profession – one that is so explicitly concerned with the design of inclusive environments – to resolve its own inequalities. Contributions have been sought and responses elicited from all corners of the discipline to propose strategies, attitudes and solutions to this crisis in representation.
At stake is more than just the lack of female representation. Male architects suffer from the same ingrained mechanisms of gender stereotyping, obliged to place professional commitments above those to their family and children. And while three quarters of lesbian, gay, bisexual and transsexual architects report being comfortable about being open about their sexuality in the workplace, that number drops to just sixteen per cent when on the building site.
A Gendered Profession will aim to perform a diagnostic check of the architecture profession from one end of the spectrum to the other. Whereas much has been written on feminism and architecture, the majority is produced exclusively by women. A Gendered Profession has worked hard towards gender parity in both its contributions and editorial structure and therefore does not limit its understanding of gender to an either/or analogue. The chapters featured in the book are written by artists, academics, practitioners and students.
Through its diverse authorship, this book will provide the first ever attempt to move the debate beyond the tradition of gender-partitioned diagnostic or merely critical discourse on the gender and wider inclusivity debate towards something more propositional, actionable and transformative.