918 research outputs found

    Quality of life in children with primary antibody deficiency.

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    Primary antibody deficiency disorders (PADs) can have an excellent outlook if diagnosed early and treated appropriately, but require lifelong treatment with immunoglobulin replacement. Some carry risks of inflammatory complications even with optimal treatment. Quality of life (QoL) and the psychological impact of PADs has been relatively little studied, particularly in children. The purpose of this study was to evaluate QoL and psychological impact in a large group of children affected by a range of PADs, as well as a group with transient hypogammaglobulinemia of infancy (THI). Both parental and, where appropriate, child ratings, were collected using standardised questionnaires (PedsQL and SDQ). Higher rates of psychological difficulties, particularly emotional and peer-relationship difficulties were found in children with PAD when compared with healthy controls. Quality of life was poorer than in healthy controls, and also worse than in children affected by diabetes mellitus. Variations in QoL and the degree of psychological difficulties were found between specific diagnostic groups, with children affected by THI being amongst those with the lowest scores for QoL. Further studies are needed to corroborate and extend these findings, but this study confirms previous findings that primary antibody deficiency has a significant impact on quality of life and psychological well-being, and additionally suggests that the impact varies according to severity of the underlying condition. For those with significant difficulties psychological intervention at an early stage may be beneficial

    A general piecewise multi-state survival model: Application to breast cancer

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    Multi-state models are considered in the field of survival analysis for modelling illnesses that evolve through several stages over time. Multi-state models can be developed by applying several techniques, such as non-parametric, semi-parametric and stochastic processes, particularly Markov processes. When the development of an illness is being analysed, its progression is tracked periodically. Medical reviews take place at discrete times, and a panel data analysis can be formed. In this paper, a discrete-time piecewise non-homogeneous Markov process is constructed for modelling and analysing a multi-state illness with a general number of states. The model is built, and relevant measures, such as survival function, transition probabilities, mean total times spent in a group of states and the conditional probability of state change, are determined. A likelihood function is built to estimate the parameters and the general number of cut-points included in the model. Time-dependent covariates are introduced, the results are obtained in a matrix algebraic form and the algorithms are shown. The model is applied to analyse the behaviour of breast cancer. A study of the relapse and survival times of 300 breast cancer patients who have undergone mastectomy is developed. The results of this paper are implemented computationally with MATLAB and R.Ministerio de Economía y Competitividad FQM-307European Regional Development Fund (ERDF) MTM2017-88708-PUniversity of Milano-Bicocca 2014-ATE-022

    Sinking properties of some phytoplankton shapes and the relation of form resistance to morphological diversity of plankton – an experimental study

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    Form resistance (Phi) is a dimensionless number expressing how much slower or faster a particle of any form sinks in a fluid medium than the sphere of equivalent volume. Form resistance factors of PVC models of phytoplankton sinking in glycerin were measured in a large aquarium (0.6 x 0.6 x 0.95 m). For cylindrical forms, a positive relationship was found between Phi and length/ width ratio. Coiling decreased Phi in filamentous forms. Form resistance of Asterionella colonies increased from single cells up to 6-celled colonies than remained nearly constant. For Fragilaria crotonensis chains, no such upper limit to Phi was observed in chains of up to 20 cells ( longer ones were not measured). The effect of symmetry on Phi was tested in 1 - 6-celled Asterionella colonies, having variable angles between the cells, and in Tetrastrum staurogeniaeforme coenobia, having different spine arrangements. In all cases, symmetric forms had considerably higher form resistance than asymmetric ones. However, for Pediastrum coenobia with symmetric/asymmetric fenestration, no difference was observed with respect to symmetry. Increasing number and length of spines on Tetrastrum coenobia substantially increased Phi. For a series of Staurastrum forms, a significant positive correlation was found between arm-length/cell-width ratio and Phi: protuberances increased form resistance. Flagellates (Rhodomonas, Gymnodinium) had a Phi 1. The highest value ( Phi = 8.1) was established for a 20-celled Fragilaria crotonensis chain. Possible origin of the so-called 'vital component' ( a factor that shows how much slower viable populations sink than morphologically similar senescent or dead ones) is discussed, as is the role of form resistance in evolution of high diversity of plankton morphologies

    A Hedged Monte Carlo Approach to Real Option Pricing

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    In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

    Retail ring-fencing of banks and its implications

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    Financial stability remains a key theme globally in view of the Euro zone debt crisis. The latest strategy by Germany and France is to ring-fence the crisis among the PIIGS countries (Portugal, Greece, Ireland, Italy and Spain). In the United Kingdom, the big four major banks have all responded to the Independent Commission of Bankings interim report key recommendation: ring-fencing retail operations into a separate subsidiary of any bank that wishes to operate in the United Kingdom. The report has clearly discussed the advantages and disadvantages of various types of subsidiarisation. Retail ring-fencing is considered a compromise as full subsidiarisation is too costly and operational subsidiarisation is too minimal. The Independent Commission of Banking published its final report on 12 September 2011. They recommended ring-fencing retail banking and a 10 per cent equity baseline. This article focuses on structural reforms of UK banks. It aims to address the question of financial stability from a wider European perspective. The first question is whether cross-border retail banking in the European Economic Area (EEA) is best served by branches or subsidiaries? The second question concerns the legality of setting up subsidiaries in the European Union (EU). Although there are no legal problems for UK-based banks setting up subsidiaries for their retail activities, there might be a legal hurdle for requiring foreign banks setting up subsidiaries in the United Kingdom. The third question concerns EU cross-border banking regulation and supervision. Are the passporting system and the home country supervisory approach still applicable in this post-financial crisis era? Many factors influence the choice of setting up branches or subsidiaries. However, the general position is that branches are more suited for wholesale/investment activities because of ease of funds transfer. Subsidiaries are more suitable for retail banking because of the limited liability principle and extensive local network. Effective cross-border banking must be accompanied by effective supervision and resolution regimes. The passporting concept under EU law and home country dominance are somewhat dated post-financial crisis. Host country control should play a dominant part in financial regulation, especially in the light of the importance of subsidiaries and the limited liability principle associated with them. The Icelandic bank crisis and collapse of Lehman Brothers International Europe illustrate the importance of host country control. Finally, the author argues that requiring banks to hold its retail activities in the form of subsidiaries in another European country is necessary to achieve financial stability. © 2012 Macmillan Publishers Ltd

    Determinantes Nacionais e Setoriais da Estrutura de Capital na América Latina

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    This study identified the role of the national environment (the Macroeconomy, Financial Development and Institutional Quality) and industry characteristics (Munificence, Dynamism, Concentration, Life Cycle, Technological Efficiency Dispersion, Product Quality Dispersion, Customer Bargaining Power and Supplier Bargaining Power) on debt of 612 listed companies from 7 Latin American countries (Argentina, Brazil, Chile, Colombia, Mexico, Peru and Venezuela). For comparison purposes, the analysis is also extended to 847 U.S. companies. The period of study is 1996-2009 and the analysis employed a Hierarchical Linear Model, which controls the effects according to the level of the variables (country, industry, time and firm). The results suggest that Financial Development eases access to external funds and Institutional Quality is negatively related to firm Leverage. The research also finds evidence that institutional quality can promote asymmetrical development between stock markets and credit markets

    Development of Resorbable Phosphate-Based Glass Microspheres as MRI Contrast Media Agents

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    In this research, resorbable phosphate-based glass (PBG) compositions were developed using varying modifier oxides including iron (Fe2O3), copper (CuO), and manganese (MnO2), and then processed via a rapid single-stage flame spheroidisation process to manufacture dense (i.e., solid) and highly porous microspheres. Solid (63–200 µm) and porous (100–200 µm) microspheres were produced and characterised via SEM, XRD, and EDX to investigate their surface topography, structural properties, and elemental distribution. Complementary NMR investigations revealed the formation of Q2, Q1, and Q0 phosphate species within the porous and solid microspheres, and degradation studies performed to evaluate mass loss, particle size, and pH changes over 28 days showed no significant differences among the microspheres (63–71 µm) investigated. The microspheres produced were then investigated using clinical (1.5 T) and preclinical (7 T) MRI systems to determine the R1 and R2 relaxation rates. Among the compositions investigated, manganese-based porous and solid microspheres revealed enhanced levels of R2 (9.7–10.5 s−1 for 1.5 T; 17.1–18.9 s−1 for 7 T) and R1 (3.4–3.9 s−1 for 1.5 T; 2.2–2.3 s−1 for 7 T) when compared to the copper and iron-based microsphere samples. This was suggested to be due to paramagnetic ions present in the Mn-based microspheres. It is also suggested that the porosity in the resorbable PBG porous microspheres could be further explored for loading with drugs or other biologics. This would further advance these materials as MRI theranostic agents and generate new opportunities for MRI contrast-enhancement oral-delivery applications
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