Validation of the Quality of Life Inventory for patients with anxiety and depression

Background: In 1992, Frisch et al (Psychol Assess. 1992;4:92- 10 1) developed the Quality of Life Inventory (QOLI) to measure the concept of quality of life (QOL) because it has long been thought to be related to both physical and emotional well-being. However, the psychometric properties of the QOLI in clinical populations are still in debate. The present study examined the factor structure of QOLI and reported its validity and reliability in a clinical sample. Method: Two hundred seventeen patients with anxiety and depressive disorders completed the QOLI and additional questionnaires measuring symptoms (Zung Self-rating Depression Scale, Beck Anxiety Inventory, Fear Questionnaire, Depression Anxiety Stress Scale-Stress) and subjective well-being (Satisfaction With Life Scale) were also used. Results: Exploratory factor analysis via the principal components method, with oblique rotation, revealed a 2-factor structure that accounted for 42.73% of the total variance, and a subsequent confirmatory factor analysis suggested a moderate fit of the data to this model. The 2 factors appeared to describe self-oriented QOL and externally oriented QOL. The Cronbach alpha coefficients were 0.85 for the overall QOLI score, 0.81 for the first factor, and 0.75 for the second factor. Conclusion: Consistent evidence was also found to support the concurrent, discriminant, predictive, and criterion-related validity of the QOLI. (c) 2006 Elsevier Inc. All rights reserved.

Comparison of the reintroduced MEIA (R) assay with HPLC-MS/MS for the determination of whole-blood sirolimus from transplant recipients

Therapeutic monitoring with dosage individualization of sirolimus drug therapy is standard clinical practice for organ transplant recipients. For several years sirolimus monitoring has been restricted as a result of lack of an immunoassay. The recent reintroduction of the microparticle enzyme immunoassay (MEIA (R)) for sirolimus on the IMx (R) analyser has the potential to address this situation. This Study, using patient samples, has compared the MEIA (R) sirolimus method with an established HPLC-tandem mass spectrometry method (HPLC-MS/MS). An established HPLC-UV assay was used for independent cross-validation. For quality control materials (5, 11, 22 mu g/L), the MEIA (R) showed acceptable validation criteria based on intra-and inter-run precision (CV) and accuracy (bias) of < 8% and < 13%, respectively. The lower limit of quantitation was found to be approximately 3 mu g/L. The performance of the immunoassay was compared with HPLC-MS/MS using EDTA whole-blood samples obtained from various types of organ transplant recipients (n = 116). The resultant Deming regression line was: MEIA = 1.3 x HPLC-MS/MS+ 1.3 (r = 0.967, s(y/x) = 1) with a mean bias of 49.2% +/- 23.1 % (range, -2.4% to 128%; P < 0.001). The reason for the large and variable bias was not explored in this study, but the sirolimus-metabolite cross-reactivity with the MEIA (R) antibody could be a substantive contributing factor. Whereas the MEIA (R) sirolimus method may be an adjunct to sirolimus dosage individualization in transplant recipients, users must consider the implications of the substantial and variable bias when interpreting results. In selected patients where difficult clinical issues arise, reference to a specific chromatographic method may be required.

Numerical modelling of advanced modulation formats and WDM transmission

This thesis presents a theoretical investigation of the application of advanced modelling formats in high-speed fibre lightwave systems. The first part of this work focuses on numerical optimisation of dense wavelength division multiplexing (DWDM) system design. We employ advanced spectral domain filtering techniques and carrier pulse reshaping. We then apply these optimisation methods to investigate spectral and temporal domain characteristics of advanced modulation formats in fibre optic telecommunication systems. Next we investigate numerical methods used in detecting and measuring the system performance of advanced modulation formats. We then numerically study the combination of return-to-zero differential phase-shift keying (RZ-DPSK) with advanced photonic devices. Finally we analyse the dispersion management of Nx40 Gbit/s RZ-DPSK transmission applied to a commercial terrestrial lightwave system.

Equilibrium properties of disordered spin models with two-scale interactions

Methods for understanding classical disordered spin systems with interactions conforming to some idealized graphical structure are well developed. The equilibrium properties of the Sherrington-Kirkpatrick model, which has a densely connected structure, have become well understood. Many features generalize to sparse Erdös- Rényi graph structures above the percolation threshold and to Bethe lattices when appropriate boundary conditions apply. In this paper, we consider spin states subject to a combination of sparse strong interactions with weak dense interactions, which we term a composite model. The equilibrium properties are examined through the replica method, with exact analysis of the high-temperature paramagnetic, spin-glass, and ferromagnetic phases by perturbative schemes. We present results of replica symmetric variational approximations, where perturbative approaches fail at lower temperature. Results demonstrate re-entrant behaviors from spin glass to ferromagnetic phases as temperature is lowered, including transitions from replica symmetry broken to replica symmetric phases. The nature of high-temperature transitions is found to be sensitive to the connectivity profile in the sparse subgraph, with regular connectivity a discontinuous transition from the paramagnetic to ferromagnetic phases is apparent.

Determination of muscle fatigue in clinical practices using dynamically embedded signals

This paper explores a new method of analysing muscle fatigue within the muscles predominantly used during microsurgery. The captured electromyographic (EMG) data retrieved from these muscles are analysed for any defining patterns relating to muscle fatigue. The analysis consists of dynamically embedding the EMG signals from a single muscle channel into an embedded matrix. The muscle fatigue is determined by defining its entropy characterized by the singular values of the dynamically embedded (DE) matrix. The paper compares this new method with the traditional method of using mean frequency shifts in the EMG signal's power spectral density. Linear regressions are fitted to the results from both methods, and the coefficients of variation of both their slope and point of intercept are determined. It is shown that the complexity method is slightly more robust in that the coefficient of variation for the DE method has lower variability than the conventional method of mean frequency analysis.

Understanding the IT-related attitudes and needs of persons with age-related macular degeneration : a case study

In the UK, 20 per cent of people aged 75 years and over are living with sight loss; this percentage is expected to increase as the population ages (RNIB, 2011). Age-Related Macular Degeneration (AMD) is the UK’s leading cause of severe visual impairment amongst the elderly. It accounts for 16,000 blind/partial sight registrations per year and is the leading cause of blindness among people aged 55 years and older in western countries (Bressler, 2004). Our ultimate goal is to develop an assistive mobile application to support accurate and convenient diet data collection on which basis to then provide customised dietary advice and recommendations in order to help support individuals with AMD to mitigate their ongoing risk and retard the progression of the disease. In this paper, we focus on our knowledge elicitation activities conducted to help us achieve a deep and relevant understanding of our target user group. We report on qualitative findings from focus groups and observational studies with persons with AMD and interviews with domain experts which enable us to fully appreciate the impact that technology may have on our intended users as well as to inform the design and structure of our proposed mobile assistive application.

Structural effects in photopolymerized sodium AMPS hydrogels crosslinked with poly(ethylene glycol) diacrylate for use as burn dressings

Synthetic hydrogel polymers were prepared by free radical photopolymerization in aqueous solution of the sodium salt of 2-acrylamido-2-methylpropane sulfonic acid (Na-AMPS). Poly(ethylene glycol) diacrylate (PEGDA) and 4,4'-azo-bis(4-cyanopentanoic acid) were used as the crosslinker and UV-photoinitiator, respectively. The effects of varying the Na-AMPS monomer concentration within the range of 30-50% w/v and the crosslinker concentration within the range of 0.1-1.0% mol (relative to monomer) were studied in terms of their influence on water absorption properties. The hydrogel sheets exhibited extremely high swelling capacities in aqueous media which were dependent on monomer concentration, crosslink density, and the ionic strength and composition of the immersion medium. The effects of varying the number-average molecular weight of the PEGDA crosslinker from = 250 to 700 were also investigated. Interestingly, it was found that increasing the molecular weight and therefore the crosslink length at constant crosslink density decreased both the rate of water absorption and the equilibrium water content. Cytotoxicity testing by the direct contact method with mouse fibroblast L929 cells indicated that the synthesized hydrogels were nontoxic. On the basis of these results, it is considered that photopolymerized Na-AMPS hydrogels crosslinked with PEGDA show considerable potential for biomedical use as dressings for partial thickness burns. This paper describes some structural effects which are relevant to their design as biomaterials for this particular application. © 2013 Copyright Taylor and Francis Group, LLC.

A fast XPS study of propene decomposition over clean and sulphated Pt{111}

The thermal decomposition of propene over clean and sulphate precovered Pt{111} has been followed by Fast XPS. The saturation propene coverage over the clean surface is 0.21 mL at 90 K. Propene is stable up to 200 K, above which molecular desorption and dehydrogenation result in the formation of a stable propylidyne intermediate adlayer at 300 K. Propylidyne decomposes above 400 K eventually forming graphitic carbon above 800 K. Preadsorbed surface sulphate promotes room temperature propene combustion associated with the decomposition of a thermally unstable alkyl--sulphate complex. Propylidyne also forms as on clean Pt{111}, but is less reactive, its decomposition above 450 K triggering partial oxidation with residual surface oxygen to liberate gas phase CO.

Understanding the IT-related attitudes and needs of persons with age-related macular degeneration:a case study

In the UK, 20 per cent of people aged 75 years and over are living with sight loss; this percentage is expected to increase as the population ages (RNIB, 2011). Age-Related Macular Degeneration (AMD) is the UK’s leading cause of severe visual impairment amongst the elderly. It accounts for 16,000 blind/partial sight registrations per year and is the leading cause of blindness among people aged 55 years and older in western countries (Bressler, 2004). Our ultimate goal is to develop an assistive mobile application to support accurate and convenient diet data collection on which basis to then provide customised dietary advice and recommendations in order to help support individuals with AMD to mitigate their ongoing risk and retard the progression of the disease. In this paper, we focus on our knowledge elicitation activities conducted to help us achieve a deep and relevant understanding of our target user group. We report on qualitative findings from focus groups and observational studies with persons with AMD and interviews with domain experts which enable us to fully appreciate the impact that technology may have on our intended users as well as to inform the design and structure of our proposed mobile assistive application.

A Refinement of some Overrelaxation Algorithms for Solving a System of Linear Equations

In this paper we propose a refinement of some successive overrelaxation methods based on the reverse Gauss–Seidel method for solving a system of linear equations Ax = b by the decomposition A = Tm − Em − Fm, where Tm is a banded matrix of bandwidth 2m + 1. We study the convergence of the methods and give software implementation of algorithms in Mathematica package with numerical examples. ACM Computing Classification System (1998): G.1.3.

First-Order Conditions for Optimization Problems with Quasiconvex Inequality Constraints

2000 Mathematics Subject Classification: 90C46, 90C26, 26B25, 49J52.

Bagging model with cost sensitive analysis on diabetes data

Diabetes patients might suffer from an unhealthy life, long-term treatment and chronic complicated diseases. The decreasing hospitalization rate is a crucial problem for health care centers. This study combines the bagging method with base classifier decision tree and costs-sensitive analysis for diabetes patients' classification purpose. Real patients' data collected from a regional hospital in Thailand were analyzed. The relevance factors were selected and used to construct base classifier decision tree models to classify diabetes and non-diabetes patients. The bagging method was then applied to improve accuracy. Finally, asymmetric classification cost matrices were used to give more alternative models for diabetes data analysis.

Svájci rendszerű sakk csapatversenyek rangsorolása (Ranking in Swiss system chess team tournaments)

A cikk a páros összehasonlításokon alapuló pontozási eljárásokat alkalmazza svájci rendszerű sakk csapatversenyek eredményének meghatározására. Bemutatjuk a nem körmérkőzéses esetben felmerülő kérdéseket, az egyéni és csapatversenyek jellemzőit, valamint a hivatalos lexikografikus rendezések hibáit. Axiomatikus alapokon rangsorolási problémaként modellezzük a bajnokságokat, definícióinkat összekapcsoljuk a pontszám, az általánosított sorösszeg és a legkisebb négyzetek módszerének tulajdonságaival. A javasolt eljárást két sakkcsapat Európa-bajnokság részletes elemzésével illusztráljuk. A végső rangsorok összehasonlítását távolságfüggvények segítségével végezzük el, majd a sokdimenziós skálázás révén ábrázoljuk azokat. A hivatalos sorrendtől való eltérés okait a legkisebb négyzetek módszerének dekompozíciójával tárjuk fel. A sorrendeket három szempont, az előrejelző képesség, a mintailleszkedés és a robusztusság alapján értékeljük, és a legkisebb négyzetek módszerének alkalmas eredménymátrixszal történő használata mellett érvelünk. ____ The paper uses paired comparison-based scoring procedures in order to determine the result of Swiss system chess team tournaments. We present the main challenges of ranking in these tournaments, the features of individual and team competitions as well as the failures of official lexicographical orders. The tournament is represented as a ranking problem, our model is discussed with respect to the properties of the score, generalised row sum and least squares methods. The proposed method is illustrated with a detailed analysis of the two recent chess team European championships. Final rankings are compared through their distances and visualized by multidimensional scaling (MDS). Differences to official ranking are revealed due to the decomposition of least squares method. Rankings are evaluated by prediction accuracy, retrodictive performance, and stability. The paper argues for the use of least squares method with an appropriate generalised results matrix favouring match points.

Ranking in Swiss system chess team tournaments

The paper uses paired comparison-based scoring procedures for ranking the participants of a Swiss system chess team tournament. We present the main challenges of ranking in Swiss system, the features of individual and team competitions as well as the failures of official lexicographical orders. The tournament is represented as a ranking problem, our model is discussed with respect to the properties of the score, generalized row sum and least squares methods. The proposed procedure is illustrated with a detailed analysis of the two recent chess team European championships. Final rankings are compared by their distances and visualized with multidimensional scaling (MDS). Differences to official ranking are revealed by the decomposition of least squares method. Rankings are evaluated by prediction accuracy, retrodictive performance, and stability. The paper argues for the use of least squares method with a results matrix favoring match points.

Reduced organic sulfur: Analysis and interaction with mercury in the aquatic environment

Reduced organic sulfur (ROS) compounds are environmentally ubiquitous and play an important role in sulfur cycling as well as in biogeochemical cycles of toxic metals, in particular mercury. Development of effective methods for analysis of ROS in environmental samples and investigations on the interactions of ROS with mercury are critical for understanding the role of ROS in mercury cycling, yet both of which are poorly studied. Covalent affinity chromatography-based methods were attempted for analysis of ROS in environmental water samples. A method was developed for analysis of environmental thiols, by preconcentration using affinity covalent chromatographic column or solid phase extraction, followed by releasing of thiols from the thiopropyl sepharose gel using TCEP and analysis using HPLC-UV or HPLC-FL. Under the optimized conditions, the detection limits of the method using HPLC-FL detection were 0.45 and 0.36 nM for Cys and GSH, respectively. Our results suggest that covalent affinity methods are efficient for thiol enrichment and interference elimination, demonstrating their promising applications in developing a sensitive, reliable, and useful technique for thiol analysis in environmental water samples. The dissolution of mercury sulfide (HgS) in the presence of ROS and dissolved organic matter (DOM) was investigated, by quantifying the effects of ROS on HgS dissolution and determining the speciation of the mercury released from ROS-induced HgS dissolution. It was observed that the presence of small ROS (e.g., Cys and GSH) and large molecule DOM, in particular at high concentrations, could significantly enhance the dissolution of HgS. The dissolved Hg during HgS dissolution determined using the conventional 0.22 μm cutoff method could include colloidal Hg (e.g., HgS colloids) and truly dissolved Hg (e.g., Hg-ROS complexes). A centrifugal filtration method (with 3 kDa MWCO) was employed to characterize the speciation and reactivity of the Hg released during ROS-enhanced HgS dissolution. The presence of small ROS could produce a considerable fraction (about 40% of total mercury in the solution) of truly dissolved mercury (< 3 kDa), probably due to the formation of Hg-Cys or Hg-GSH complexes. The truly dissolved Hg formed during GSH- or Cys-enhanced HgS dissolution was directly reducible (100% for GSH and 40% for Cys) by stannous chloride, demonstrating its potential role in Hg transformation and bioaccumulation.