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In recent years, the discovery of massive quasars at
has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.
The use of three-dimensional printing has been rapidly expanding over the last several decades. Virtual surgical three-dimensional simulation and planning has been shown to increase efficiency and accuracy in various clinical scenarios.
To report the feasibility of three-dimensional printing in paediatric laryngotracheal stenosis and discuss potential applications of three-dimensional printed models in airway surgery.
Retrospective case series in a tertiary care aerodigestive centre.
Three-dimensional printing was undertaken in two cases of paediatric laryngotracheal stenosis. One patient with grade 4 subglottic stenosis with posterior glottic involvement underwent an extended partial cricotracheal reconstruction. Another patient with grade 4 tracheal stenosis underwent tracheal resection and end-to-end anastomosis. Models of both tracheas were printed using PolyJet technology from a Stratasys Connex2 printer.
It is feasible to demonstrate stenosis in three-dimensional printed models, allowing for patient-specific pre-operative surgical simulation. The models serve as an educational tool for patients’ understanding of the surgery, and for teaching residents and fellows.
Epistemic justifications for democracy have been offered in terms of two different forms of information aggregation and decision-making. The Condorcet Jury Theorem is appealed to as a justification in terms of votes, and the Hong–Page ‘diversity trumps ability’ result is appealed to as a justification in terms of deliberation in the form of collaborative search. Both results, however, are models of full and direct participation across a population. In this paper, we contrast how these results hold up within the familiar structure of a representative hierarchy. We first consider extant analytic work that shows that representation inevitably weakens the voting results of the Condorcet Jury Theorem. We then go on to show that collaborative search, as modeled by Hong and Page, holds its own within hierarchical representation. In a variation on the dynamics of group search, representation even shows a slight edge over direct participation. This contrast illustrates how models of information aggregation vary when put into a representative structure. While some of the epistemic merits of democracy are lost when voting is done hierarchically, modeling results show that representation can preserve and even slightly amplify the epistemic virtues of collaborative search.
The aims of this study were to investigate the effects of either hearing, vision or dual sensory impairment on depressive symptoms and to identify subgroups that are vulnerable and significantly affected.
Data from the 2006–2014 Korean Longitudinal Study of Aging (KLoSA) were used and a total of 5832 individuals were included in this study. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D10) scale. Sensory impairment was assessed according to the levels of self-reported hearing or vision, which were categorised as either good (excellent, very good or good) or poor (fair or poor). The changes in hearing or vision from records of previous survey were investigated. Changes from good to poor, which indicates new onset, were defined as hearing impairment or vision impairment. Interactions of changes in hearing and vision were considered in the analysis. Dual sensory impairment was indicated when hearing impairment and vision impairment both developed at the same time. Demographic, socioeconomic and health-related factors were considered as potential confounders and were adjusted for in the generalised estimating equation model.
Individuals with hearing impairment demonstrated significantly more severe depressive symptoms [β = 0.434, standard errors (s.e.) = 0.097, p < 0.001] than those who had good hearing. Those with vision impairment also showed significantly elevated depressive symptoms (β = 0.253, s.e. = 0.058, p < 0.001) than those with good vision. When the interactions between hearing and vision were considered, participants with dual sensory impairment showed significantly more severe depressive symptoms (β = 0.768, s.e. = 0.197, p < 0.001) than those with good hearing and vision. The effect of a single and dual sensory impairment on depressive symptoms was significant in both sexes and across age groups, except for vision impairment in male participants.
Hearing, vision and dual sensory impairment are significantly associated with depressive symptoms. Our results suggest that treatment or rehabilitation of either hearing or vision impairment would help prevent depression.
Clinical research studies of behavioral variant frontotemporal dementia (bvFTD) often use Alzheimer disease (AD) as a comparison group for control of dementia variables, using tests of cognitive function to match the groups. These two dementia syndromes, however, are very different in clinical manifestations, and the comparable severity of these dementias may not be reflected by commonly used cognitive scales such as the Mini-Mental State Examination (MMSE).
We evaluated different measures of dementia severity and symptoms among 20 people with bvFTD compared to 24 with early-onset AD.
Despite similar ages, disease-duration, education, and cognitive performance on two tests of cognitive function, the MMSE and the Montreal Cognitive Assessment (MoCA), the bvFTD participants, compared to the AD participants, were significantly more impaired on other measures of disease severity, including function (Functional Assessment Questionnaire (FAQ)), neuropsychiatric symptoms (Neuropsychiatric Inventory (NPI)), and global dementia stage (Clinical Dementia Rating Scales (CDRs)). However, when we adjusted for the frontotemporal lobar degeneration-CDR (FTLD-CDR) in the analyses, the two dementia groups were comparable across all measures despite significant differences on the cognitive scales.
We found tests of cognitive functions (MMSE and MoCA) to be insufficient measures for ensuring comparability between bvFTD and AD groups. In clinical studies, the FTLD-CDR, which includes additional language and behavior items, may be a better overall way to match bvFTD and AD groups on dementia severity.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
To identify clinical factors that can explain the differences in treatment outcome, and examine the value of human papillomavirus infection as a prognostic biomarker in stage IVa tonsillar carcinomas.
Fifty-nine patients with tonsillar carcinoma classified as stage IVa were retrospectively analysed for survival outcomes according to various clinical factors. Human papillomavirus infection was evaluated using a human papillomavirus DNA chip test and immunohistochemical staining for p16 and p53.
Lower disease-free survival rates were associated with increasing local invasiveness and nodal status. Although human papillomavirus positivity and p16 expression was more common in locally advanced tonsillar carcinomas with advanced nodal status, the overall survival rate was better for patients with human papillomavirus positive, p16-positive tumours.
The disease-free survival rate may differ according to local tumour invasiveness and nodal status, even for stage IVa tonsillar cancers. Human papillomavirus infection may be a useful biomarker for predicting treatment outcomes for stage VIa tumours.
The grown-in tensile strain, due to a lattice mismatch between AlGaN and GaN, is responsible for the observed cracking that seriously limits the feasibility of nitride-based ultraviolet (UV) emitters. We report in-situ monitoring of strain/stress during MOCVD of AlGaN based on a wafer-curvature measurement technique. The strain/stress measurement confirms the presence of tensile strain during growth of AlGaN pseudomorphically on a thick GaN layer. Further growth leads to the onset of stress relief through crack generation. We find that the growth of AlGaN directly on low-temperature (LT) GaN or AlN buffer layers results in a reduced and possibly controllable strain.
This study aimed to evaluate the efficacy of post-operative voice therapy after phonomicrosurgery for vocal polyp removal.
The study retrospectively enrolled 55 consecutive patients who had undergone voice therapy after phonomicrosurgery for vocal polyp removal occurring between June 2010 and June 2011. A historical group of 63 similar patients not receiving voice therapy was used as an external control. We compared voice analysis parameters and Voice Handicap Index scores for the two groups.
Most objective and subjective voice outcome parameters were significantly improved after surgical treatment. Although the study and control groups showed no significant difference regarding objective parameters (using acoustic and aerodynamic analysis) or the subjective parameters assessed using the grade-roughness-breathiness-asthenia-strain scale, the study group had significantly better final Voice Handicap Index scores.
Following surgery for vocal polyps, post-operative voice therapy can improve patients' vocal discomfort, emotional responses and everyday self-perception.
The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov
satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector,
called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB
and then triggers to determine the direction of the GRB and then alerts the Slewing Mirror
Telescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes.
This report details the calibration of the two components: the MAPMTs and the YSO crystals
and simulations of the UBAT. The results shows that this design can observe a GRB within a
field of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 s
after the appearance of a GRB X-ray spike.
The Ultra-Fast Flash Observatory (UFFO), which will be launched onboard the
Lomonosov spacecraft, contains two crucial instruments: UFFO Burst
Alert & Trigger Telescope (UBAT) for detection and localization of Gamma-Ray Bursts
(GRBs) and the fast-response Slewing Mirror Telescope (SMT) designed for the observation
of the prompt optical/UV counterparts. Here we discuss the in-space calibrations of the
UBAT detector and SMT telescope. After the launch, the observations of the standard X-ray
sources such as pulsar in Crab nebula will provide data for necessary calibrations of
UBAT. Several standard stars will be used for the photometric calibration of SMT. The
celestial X-ray sources, e.g. X-ray binaries with bright optical sources
in their close angular vicinity will serve for the cross-calibration of UBAT and SMT.
We report the microstructural features of GdBa2Cu3O7-δ (GdBCO) coated conductors (CCs) on LaMnO3 (LMO)-buffered IBAD MgO template, produced by the Reactive Co-Evaporation Deposition & Reaction (RCE-DR) process. Analysis results by X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that a lot of elongated round second phase particles of 70-150nm size within the GdBCO matrix were the Gd2O3 phase, a small amount of Cu-O phase were also trapped in the GdBCO matrix, and a thick layer of Cu-excessive Ba-Cu-O phase was found on the top surface of the GdBCO film, suggesting that the GdBCO film might be grown from Gd2O3 and liquid phase by a peritectic recombination. While both the GdBCO film and some Gd2O3 particles grown on the LMO-buffer layer were biaxially textured, the Gd2O3 particles fully trapped in the GdBCO matrix were randomly oriented. The Gd2O3 particles located at the interface between the GdBCO and LMO buffer layer exhibited the following crystallographic orientation relationship: LMO  // GdBCO  // Gd2O3 ; LMO  // GdBCO  // Gd2O3 .
We previously developed and validated an index of socioeconomic status (SES) termed HOUSES (housing-based index of socioeconomic status) based on real property data. In this study, we assessed whether HOUSES overcomes the absence of SES measures in medical records and is associated with risk of invasive pneumococcal disease (IPD) in children. We conducted a population-based case-control study of children in Olmsted County, MN, diagnosed with IPD (1995–2005). Each case was age- and gender-matched to two controls. HOUSES was derived using a previously reported algorithm from publicly available housing attributes (the higher HOUSES, the higher the SES). HOUSES was available for 92·3% (n = 97) and maternal education level for 43% (n = 45). HOUSES was inversely associated with risk of IPD in unmatched analysis [odds ratio (OR) 0·22, 95% confidence interval (CI) 0·05–0·89, P = 0·034], whereas maternal education was not (OR 0·77, 95% CI 0·50–1·19, P = 0·24). HOUSES may be useful for overcoming a paucity of conventional SES measures in commonly used datasets in epidemiological research.