3,824 research outputs found
Validation of a novel scoring system for changes in skeletal manifestations of hypophosphatasia in newborns, infants, and children: The Radiographic Global Impression of Change scale
Hypophosphatasia (HPP) is the heritable metabolic disease characterized by impaired skeletal mineralization due to low activity of the tissue-nonspecific isoenzyme of alkaline phosphatase. Although HPP during growth often manifests with distinctive radiographic skeletal features, no validated method was available to quantify them, including changes over time. We created the Radiographic Global Impression of Change (RGI-C) scale to assess changes in the skeletal burden of pediatric HPP. Site-specific pairs of radiographs of newborns, infants, and children with HPP from three clinical studies of asfotase alfa, an enzyme replacement therapy for HPP, were obtained at baseline and during treatment. Each pair was scored by three pediatric radiologists ( raters ), with nine raters across the three studies. Intrarater and interrater agreement was determined by weighted Kappa coefficients. Interrater reliability was assessed using intraclass correlation coefficients (ICCs) and by two-way random effects analysis of variance (ANOVA) and a mixed-model repeated measures ANOVA. Pearson correlation coefficients evaluated relationships of the RGI-C to the Rickets Severity Scale (RSS), Pediatric Outcomes Data Collection Instrument Global Function Parent Normative Score, Childhood Health Assessment Questionnaire Disability Index, 6-Minute Walk Test percent predicted, and Z-score for height in patients aged 6 to 12 years at baseline. Eighty-nine percent (8/9) of raters showed substantial or almost perfect intrarater agreement of sequential RGI-C scores (weighted Kappa coefficients, 0.72 to 0.93) and moderate or substantial interrater agreement (weighted Kappa coefficients, 0.53 to 0.71) in patients aged 0 to 12 years at baseline. Moderate-to-good interrater reliability was observed (ICC, 0.57 to 0.65). RGI-C scores were significantly (p ≤ 0.0065) correlated with the RSS and with measures of global function, disability, endurance, and growth in the patients aged 6 to 12 years at baseline. Thus, the RGI-C is valid and reliable for detecting clinically important changes in skeletal manifestations of severe HPP in newborns, infants, and children, including during asfotase alfa treatment. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc
Correlations in Systems of Complex Directed Macromolecules
An ensemble of directed macromolecules on a lattice is considered, where the
constituting molecules are chosen as a random sequence of N different types.
The same type of molecules experiences a hard-core (exclusion) interaction. We
study the robustness of the macromolecules with respect to breaking and
substituting individual molecules, using a 1/N expansion. The properties depend
strongly on the density of macromolecules. In particular, the macromolecules
are robust against breaking and substituting at high densities.Comment: 9 pages, 4 figure
Creep motion of a model frictional system
We report on the dynamics of a model frictional system submitted to minute
external perturbations. The system consists of a chain of sliders connected
through elastic springs that rest on an incline. By introducing cyclic
expansions and contractions of the springs we observe a reptation of the chain.
We account for the average reptation velocity theoretically. The velocity of
small systems exhibits a series of plateaus as a function of the incline angle.
Due to elastic e ects, there exists a critical amplitude below which the
reptation is expected to cease. However, rather than a full stop of the creep,
we observe in numerical simulations a transition between a continuous-creep and
an irregular-creep regime when the critical amplitude is approached. The latter
transition is reminiscent of the transition between the continuous and the
irregular compaction of granular matter submitted to periodic temperature
changes
Novel RF quasi-optical components for THZ astronomy
There have been many successful THz instruments used in ground and space based telescopes that operate over a range of frequencies from 10s of GHz up to 10s of THz. For some instruments, their operation depends on precise ltering of the received radiation, which can be achieved by using metal mesh lters. These lters can also be referred to as frequency selective surface, which are part of a broad category of metamaterials. By controlling the geometry of these surfaces and combining multiple layers, it is possible to steer the radiation or control the polarisation. This thesis expands on using existing knowledge and fabrication techniques of metal mesh structures to build new quasi-optical devices, which could be a lightweight replacement for existing components, such as lenses, or new devices with properties that are not possible using traditional materials. Initially an analysis of suitable modelling methods to predict the behaviour of the individual gird structures is performed. It is then shown that multiple girds can be combined to create an arti cial dielectric. By using the developed modelling tools a parameter space is found which sets a practical limit on devices that can be built. This theory is also applied to rectangular grids, which have the same properties, but are polarisation dependent. With this framework in place, a series of devices are designed and characterised. This includes a broadband gradient index at lens, which was characterised using a VNA from 90 to 220GHz. This design was modi ed to produce a lens that is capable of separating out two orthogonal linear polarisations and focusing them separated on the same focal plane. Finally an analysis of di erent of arti cial waveplates is performed, to determine which metamaterial structures are best suited for replacing traditional sapphire waveplates
Report of the direct infrared sensors panel
The direct infrared sensors panel considered a wide range of options for technologies relevant to the science goals of the Astrotech 21 mission set. Among the technologies assessed are: large format arrays; photon counting detectors; higher temperature 1 to 10 micro-m arrays; impurity band conduction (IBC) or blocked impurity band (BIB) detectors; readout electronics; and adapting the Space Infrared Telescope Facility and Hubble Space Telescope. Detailed development plans were presented for each of these technology areas
Single-strand selective monofunctional uracil-DNA glycosylase (SMUG1) deficiency is linked to aggressive breast cancer and predicts response to adjuvant therapy
Uracil in DNA is an important cause of mutagenesis. SMUG1 is a uracil DNA glycosylase that removes uracil through base excision repair. SMUG1 also processes radiation induced oxidative base damage as well as 5-fluorouracil incorporated into DNA during chemotherapy. We investigated SMUG1 mRNA expression in 249 primary breast cancers. SMUG1 protein expression was investigated in 1165 breast tumours randomised into two cohorts [training set (n=583) and test set (n=582)]. SMUG1 and chemotherapy response was also investigated in a series of 315 ER negative tumours (n=315). For mechanistic insights, SMUG1 was correlated to biomarkers of aggressive phenotype, DNA repair, cell cycle and apoptosis. Low SMUG1 mRNA expression was associated with adverse disease specific survival (p=0.008) and disease free survival (p=0.008). Low SMUG1 protein expression (25%) was associated with high histological grade (p<0.0001), high mitotic index (p<0.0001), pleomorphism (p<0.0001), glandular de-differentiation (p=0.0001), absence of hormonal receptors (ER-/PgR-/AR) (p<0.0001), presence of basal-like (p<0.0001) and triple negative phenotypes (p<0.0001). Low SMUG1 protein expression was associated with loss of BRCA1 (p<0.0001), ATM (p<0.0001) and XRCC1 (p<0.0001). Low p27 (p<0.0001), low p21 (p=0.023), mutant p53 (p=0.037), low MDM2 (p<0.0001), low MDM4 (p=0.004), low Bcl-2 (p=0.001), low Bax (p=0.003) and high MIB1 (p<0.0001) were likely in low SMUG1 tumours. Low SMUG1 protein expression was associated with poor prognosis in univariate (p<0.001) and multivariate analysis (p<0.01). In ER+ cohort that received adjuvant endocrine therapy, low SMUG1 protein expression remains associated with poor survival (p<0.01). In ER- cohort that received adjuvant chemotherapy, low SMUG1 protein expression is associated with improved survival (p=0.043). Our study suggests that low SMUG1 expression may correlate to adverse clinicopathological features and predict response to adjuvant therapy in breast cancer
Measurement practices in hallucinations research
Introduction
In several sub-fields of psychology, there has been a renewed focus on measurement practices. As far as we are aware, this has been absent in hallucinations research. Thus, we investigated (a) cross-study variation in how hallucinatory experiences are measured and (b) the reliability of measurements obtained using two tasks that are widely employed in hallucinations research.
Method
In Study 1, we investigated to what extent there was variation in how the Launay-Slade Hallucination Scale (LSHS) has been used across 100 studies. In Study 2, we investigated the reliability of the measurements obtained through source monitoring and signal detection tasks, using data from four recent publications. Materials/data are available at doi: 10.17605/osf.io/d3gnk/.
Results
In Study 1, we found substantial variation in how hallucinatory experiences were assessed using the LSHS and that descriptions of the LSHS were often incomplete in important ways. In Study 2, we reported a range of reliability estimates for the measurements obtained using source monitoring and signal discrimination tasks. Some measurements obtained using source monitoring tasks had unacceptably low levels of reliability.
Conclusions
Our findings suggest that suboptimal measurement practices are common in hallucinations research and we suggest steps researchers could take to improve measurement practices
Displaying desire and distinction in housing
The article discusses the significance of cultural capital for the understanding of the field of housing in contemporary Britain. It explores the relationship between housing and the position of individuals in social space mapped out by means of a multiple correspondence analysis. It considers the material aspects of housing and the changing contexts that are linked to the creation and display of desire for social position and distinction expressed in talk about home decoration as personal expression and individuals' ideas of a `dream house'. It is based on an empirical investigation of taste and lifestyle using nationally representative survey data and qualitative interviews. The article shows both that personal resources and the imagination of home are linked to levels of cultural capital, and that rich methods of investigation are required to grasp the significance of these normally invisible assets to broaden the academic understanding of the field of housing in contemporary culture
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