A comparative study of the structure of sodium borophosphates made by sol-gel and melt-quench methods

The atomic scale structure of sodium borophosphates made by the sol-gel method is compared to those made by the melt-quench method. It is found that although the sol-gel generated materials have a higher tendency towards crystallization, they nevertheless show a qualitatively similar crystallization trend with composition to their melt-quench analogues; the progressive introduction of boron oxide into the phosphate network initially inhibits then promotes crystallization. At the composition associated with the most stable amorphous sodium borophosphate (20 mol% boron oxide), it is found that the atomic scale structure of the sol-gel synthesized network glass is almost identical to that of the corresponding melt-quenched one.

A method for systematic artifact selection decision making

Artifact selection decisions typically involve the selection of one from a number of possible/candidate options (decision alternatives). In order to support such decisions, it is important to identify and recognize relevant key issues of problem solving and decision making (Albers, 1996; Harris, 1998a, 1998b; Jacobs & Holten, 1995; Loch & Conger, 1996; Rumble, 1991; Sauter, 1999; Simon, 1986). Sauter classifies four problem solving/decision making styles: (1) left-brain style, (2) right-brain style, (3) accommodating, and (4) integrated (Sauter, 1999). The left-brain style employs analytical and quantitative techniques and relies on rational and logical reasoning. In an effort to achieve predictability and minimize uncertainty, problems are explicitly defined, solution methods are determined, orderly information searches are conducted, and analysis is increasingly refined. Left-brain style decision making works best when it is possible to predict/control, measure, and quantify all relevant variables, and when information is complete. In direct contrast, right-brain style decision making is based on intuitive techniques—it places more emphasis on feelings than facts. Accommodating decision makers use their non-dominant style when they realize that it will work best in a given situation. Lastly, integrated style decision makers are able to combine the left- and right-brain styles—they use analytical processes to filter information and intuition to contend with uncertainty and complexity.

Investigating the molecular structures of solid dispersions by the simulated annealing method

Knowledge of the molecular structures of solid dispersions is vital, yet, despite thousands of reports in this area, it remains unclear. The aim of this research is to investigate the molecular structure of solid dispersions with hot melt preparation method by the simulated annealing method. Simulation results showed linear polymer chains form the random coils under heat and the drug molecules stick on the surface of polymer coils, while drug molecules are dispersed molecularly but irregularly within the amorphous low molecular weight carriers. This research presents more reasonable molecular images of solid dispersions than the existed theory.

A fuzzy levelised energy cost method for renewable energy technology assessment

Renewable energy project development is highly complex and success is by no means guaranteed. Decisions are often made with approximate or uncertain information yet the current methods employed by decision-makers do not necessarily accommodate this. Levelised energy costs (LEC) are one such commonly applied measure utilised within the energy industry to assess the viability of potential projects and inform policy. The research proposes a method for achieving this by enhancing the traditional discounting LEC measure with fuzzy set theory. Furthermore, the research develops the fuzzy LEC (F-LEC) methodology to incorporate the cost of financing a project from debt and equity sources. Applied to an example bioenergy project, the research demonstrates the benefit of incorporating fuzziness for project viability, optimal capital structure and key variable sensitivity analysis decision-making. The proposed method contributes by incorporating uncertain and approximate information to the widely utilised LEC measure and by being applicable to a wide range of energy project viability decisions. © 2013 Elsevier Ltd. All rights reserved.

A method for systematic artifact selection decision making

Artifact selection decisions typically involve the selection of one from a number of possible/candidate options (decision alternatives). In order to support such decisions, it is important to identify and recognize relevant key issues of problem solving and decision making (Albers, 1996; Harris, 1998a, 1998b; Jacobs & Holten, 1995; Loch & Conger, 1996; Rumble, 1991; Sauter, 1999; Simon, 1986). Sauter classifies four problem solving/decision making styles: (1) left-brain style, (2) right-brain style, (3) accommodating, and (4) integrated (Sauter, 1999). The left-brain style employs analytical and quantitative techniques and relies on rational and logical reasoning. In an effort to achieve predictability and minimize uncertainty, problems are explicitly defined, solution methods are determined, orderly information searches are conducted, and analysis is increasingly refined. Left-brain style decision making works best when it is possible to predict/control, measure, and quantify all relevant variables, and when information is complete. In direct contrast, right-brain style decision making is based on intuitive techniques—it places more emphasis on feelings than facts. Accommodating decision makers use their non-dominant style when they realize that it will work best in a given situation. Lastly, integrated style decision makers are able to combine the left- and right-brain styles—they use analytical processes to filter information and intuition to contend with uncertainty and complexity.

Toward the prediction of class I and II mouse major histocompatibility complex-peptide-binding affinity:in silico bioinformatic step-by-step guide using quantitative structure-activity relationships

Quantitative structure-activity relationship (QSAR) analysis is a cornerstone of modern informatics. Predictive computational models of peptide-major histocompatibility complex (MHC)-binding affinity based on QSAR technology have now become important components of modern computational immunovaccinology. Historically, such approaches have been built around semiqualitative, classification methods, but these are now giving way to quantitative regression methods. We review three methods--a 2D-QSAR additive-partial least squares (PLS) and a 3D-QSAR comparative molecular similarity index analysis (CoMSIA) method--which can identify the sequence dependence of peptide-binding specificity for various class I MHC alleles from the reported binding affinities (IC50) of peptide sets. The third method is an iterative self-consistent (ISC) PLS-based additive method, which is a recently developed extension to the additive method for the affinity prediction of class II peptides. The QSAR methods presented here have established themselves as immunoinformatic techniques complementary to existing methodology, useful in the quantitative prediction of binding affinity: current methods for the in silico identification of T-cell epitopes (which form the basis of many vaccines, diagnostics, and reagents) rely on the accurate computational prediction of peptide-MHC affinity. We have reviewed various human and mouse class I and class II allele models. Studied alleles comprise HLA-A*0101, HLA-A*0201, HLA-A*0202, HLA-A*0203, HLA-A*0206, HLA-A*0301, HLA-A*1101, HLA-A*3101, HLA-A*6801, HLA-A*6802, HLA-B*3501, H2-K(k), H2-K(b), H2-D(b) HLA-DRB1*0101, HLA-DRB1*0401, HLA-DRB1*0701, I-A(b), I-A(d), I-A(k), I-A(S), I-E(d), and I-E(k). In this chapter we show a step-by-step guide into predicting the reliability and the resulting models to represent an advance on existing methods. The peptides used in this study are available from the AntiJen database (http://www.jenner.ac.uk/AntiJen). The PLS method is available commercially in the SYBYL molecular modeling software package. The resulting models, which can be used for accurate T-cell epitope prediction, will be made are freely available online at the URL http://www.jenner.ac.uk/MHCPred.

Structure of glassy GeO2

The full set of partial structure factors for glassy germania, or GeO2, were accurately measured by using the method of isotopic substitution in neutron diffraction in order to elucidate the nature of the pair correlations for this archetypal strong glass former. The results show that the basic tetrahedral Ge(O-1/2)(4) building blocks share corners with a mean inter-tetrahedral Ge-O-Ge bond angle of 132(2)degrees. The topological and chemical ordering in the resultant network displays two characteristic length scales at distances greater than the nearest neighbour. One of these describes the intermediate range order, and manifests itself by the appearance of a first sharp diffraction peak in the measured diffraction patterns at a scattering vector k(FSDP) approximate to 1.53 angstrom(-1), while the other describes so-called extended range order, and is associated with the principal peak at k(PP) = 2.66( 1) angstrom(-1). We find that there is an interplay between the relative importance of the ordering on these length scales for tetrahedral network forming glasses that is dominated by the extended range ordering with increasing glass fragility. The measured partial structure factors for glassy GeO2 are used to reproduce the total structure factor measured by using high energy x-ray diffraction and the experimental results are also compared to those obtained by using classical and first principles molecular dynamics simulations.

Structure-sensitive biodiesel synthesis over MgO nanocrystals

Size-controlled MgO nanocrystals were synthesised via a simple sol-gel method and their bulk and surface properties characterised by powder XRD, HRTEM and XPS. Small, cubic MgO single crystals, generated by low temperature processing, expose weakly basic (100) surfaces. High temperature annealing transforms these into large, stepped cuboidal nanoparticles of periclase MgO which terminate in more basic (110) and (111) surfaces. The size dependent evolution of surface electronic structure correlates directly with the associated catalytic activity of these MgO nanocrystals towards glyceryl tributyrate transesterification, revealing a pronounced structural preference for (110) and (111) facets. © 2009 The Royal Society of Chemistry.

Infer user interests via link structure regularization

Learning user interests from online social networks helps to better understand user behaviors and provides useful guidance to design user-centric applications. Apart from analyzing users' online content, it is also important to consider users' social connections in the social Web. Graph regularization methods have been widely used in various text mining tasks, which can leverage the graph structure information extracted from data. Previously, graph regularization methods operate under the cluster assumption that nearby nodes are more similar and nodes on the same structure (typically referred to as a cluster or a manifold) are likely to be similar. We argue that learning user interests from complex, sparse, and dynamic social networks should be based on the link structure assumption under which node similarities are evaluated based on the local link structures instead of explicit links between two nodes. We propose a regularization framework based on the relation bipartite graph, which can be constructed from any type of relations. Using Twitter as our case study, we evaluate our proposed framework from social networks built from retweet relations. Both quantitative and qualitative experiments show that our proposed method outperforms a few competitive baselines in learning user interests over a set of predefined topics. It also gives superior results compared to the baselines on retweet prediction and topical authority identification. © 2014 ACM.

A method using long digital straight segments for fingerprint recognition

In this paper, we proposed a new method using long digital straight segments (LDSSs) for fingerprint recognition based on such a discovery that LDSSs in fingerprints can accurately characterize the global structure of fingerprints. Different from the estimation of orientation using the slope of the straight segments, the length of LDSSs provides a measure for stability of the estimated orientation. In addition, each digital straight segment can be represented by four parameters: x-coordinate, y-coordinate, slope and length. As a result, only about 600 bytes are needed to store all the parameters of LDSSs of a fingerprint, as is much less than the storage orientation field needs. Finally, the LDSSs can well capture the structural information of local regions. Consequently, LDSSs are more feasible to apply to the matching process than orientation fields. The experiments conducted on fingerprint databases FVC2002 DB3a and DB4a show that our method is effective.

Quantitative structure-activity relationships and the prediction of MHC supermotifs

The underlying assumption in quantitative structure–activity relationship (QSAR) methodology is that related chemical structures exhibit related biological activities. We review here two QSAR methods in terms of their applicability for human MHC supermotif definition. Supermotifs are motifs that characterise binding to more than one allele. Supermotif definition is the initial in silico step of epitope-based vaccine design. The first QSAR method we review here—the additive method—is based on the assumption that the binding affinity of a peptide depends on contributions from both amino acids and the interactions between them. The second method is a 3D-QSAR method: comparative molecular similarity indices analysis (CoMSIA). Both methods were applied to 771 peptides binding to 9 HLA alleles. Five of the alleles (A*0201, A* 0202, A*0203, A*0206 and A*6802) belong to the HLA-A2 superfamily and the other four (A*0301, A*1101, A*3101 and A*6801) to the HLA-A3 superfamily. For each superfamily, supermotifs defined by the two QSAR methods agree closely and are supported by many experimental data.

Incremental tensor biased discriminant analysis:a new color-based visual tracking method

Most existing color-based tracking algorithms utilize the statistical color information of the object as the tracking clues, without maintaining the spatial structure within a single chromatic image. Recently, the researches on the multilinear algebra provide the possibility to hold the spatial structural relationship in a representation of the image ensembles. In this paper, a third-order color tensor is constructed to represent the object to be tracked. Considering the influence of the environment changing on the tracking, the biased discriminant analysis (BDA) is extended to the tensor biased discriminant analysis (TBDA) for distinguishing the object from the background. At the same time, an incremental scheme for the TBDA is developed for the tensor biased discriminant subspace online learning, which can be used to adapt to the appearance variant of both the object and background. The experimental results show that the proposed method can track objects precisely undergoing large pose, scale and lighting changes, as well as partial occlusion. © 2009 Elsevier B.V.

The structure and dynamics of saxicolous lichen communities

The saxicolous lichen vegetation on Ordovician slate rock at the mouth of the River Dovey, South Merionethshire, Wales was described in relation to several environmental variables which include aspect, slope angle, light intensity, rock porosity, rock microtopography and rock stability. Each of the measured environmental variables was shown to influence the lichen vegetation. A number of groups of species which were characteristic of certain environments were described. The data from the saxicolous lichen communities were analysed using multivariate analysis. Qualitative and quantitative data were ordinated, the qualitative data being easier to interpret ecologically, and site number (which reflects distance from the sea and altitude), rock porosity and light intensity were shown to be important environmental variables. A classification of the data was also carried out. The results of the ordination and classification were combined together and a model constructed which describes saxicolous lichen vegetation. A method which uses the model as an aid to the design and interpretation of field experiments is described. The model is applied to an experiment which investigates the effect on growth of transplanting four saxicolous lichens to different aspects. Growth was inhibited in Physcia orbicularis and Parmelia conspersa on rock surfaces of northwest aspect compared with growth on rock surfaces of southeast aspect. Growth was inhibited in Parmelia glabratula ssp. fuliginosa on rock surfaces of southeast aspect compared with rock surfaces of northwesr aspect. The growth of Parmelia saxatilis was similar at both southeast and northwesr aspects. Growth inhibition or stimulation in thalli of Physcia orbicularis, Parmelia conspersa and Parmelia glabratula ssp. fuliginosa after transplantation was consistent with the predictions of the model while the results for Parmelia saxatilis were not as expected. There was evidence that the frequency of Parmelia conspersa and Parmelia glabratula at a site is related to an effect of the environment on the growth of the thalli. There was also evidence that the frequency of Physcia orbicularis at a site is related to an effect of the environment on the establishment phase of the thalli and for the competitive exclusion of Parmelia saxatilis thalli from southeast facing rock surfaces. The distribution of lichens in relation to height on nine rock surfaces was investigated. It was suggested that the distribution of the lichens was influenced by microclimatic factors which are related to height on the rock, environmental variables which are associated with the rock substratum (e.g. rock porosity and rock microtopography) and by historical factors. The pattern of one crustose and one foliose lichen on four rock surfaces of different aspect and slope was investigated. On the vertically inclined surface the density of small thalli of Buellia aethalea and Parmelia glabratula ssp fuliginosa was correlated with the microtopography of the surface in transects horizontally across the rock surface but not in transects vertically down the rock surface. there were consitent differences in the scale and intensity of pattern horizontally and vertically and also a decrease in the intensity of pattern vertically as the slope of the rock surface decreased. These results were consistent with the suggestion of a gradient of microclimatic factors up the rock. The differences in the scale and intensity of pattern in different size classes in the population were consistent with the changes in pattern with time which have been shown to occur during succession in sand dune and salt marsh vegetation. The relationship between thallus size and height on a rock surface and between the radial growth rate and location of a thallus on a rock surface were investigated. Thalli of Parmelia glabratula ssp. fuliginosa were larger at the top of the rock surface than at the bottom and the data were consistent with the suggestion that the colonisation of the rock surface began at the top and, in time, spread downwards. The radial growth rate of the thalli could not be related to variation in slope, porosity, microtopography or directly to height on the rock but could be related to the horizontal location of the thalli on the rock. These results were consistent with the suggestion that here is a gradient of microclimatic factors across the rock surface which is also modified by height on the rock surface. The succession of lichen communities was described by relating the vegetation to rock porosity, rock microtopography, species diversity and rock stability. An initial stage dominated by crustose lichens leads to communities dominated by crustose, foliose and fruticose species. In the late stages of the succession on some rock surfaces crustose species again become dominant. The occurrence of the climax state and cyclic vegetation change in lichen communities are discussed. A mthod of estimating the age structure of a lichen population by relating thallus size to growth rate is described. The sources of error in the method are discussed in some detail and several refinements suggested to increase the accuracy of the method. The population dynamics of Parmelia glabratula ssp. fuliginosa was investigated by applying life tables to the age structures of eight different populations. The data were consistent with a period of relatively constant recruitment of thalli into the populations. Mortality in lichen populations was divided into deaths which occur after fragmentation of the thallus and deaths which occur after catastrophic environmental events. THe data suggest that the rate of fragmenting death is dependent on the age of the thallus while the rate of catastrophic death is dependent on the number of thalli established in an age class. A comparison of the numbers of thalli in each age class in the eight populations suggested that population density is controlled firstly, by climate and secondly, by variables related to the local rock surface environment. The rate of fragmenting death is related to the diversity of the community and the influence of diversity together with environmental variables in fluctuating or cyclic changes in population number.

Physicochemical characterization of grewia polysaccharide gum:effect of drying method

Grewia polysaccharide gum, a potential pharmaceutical excipient was extracted from the inner stem bark of Grewia mollis, thereupon drying was achieved by three techniques: air-drying, freeze-drying and spray-drying. Analysis of the monosaccharide composition including 1H and 13C NMR spectroscopic analysis of the polysaccharide gum was carried out. The effect of the drying methods on the physicochemical properties of the gum was evaluated by Fourier transformed infra-red (FT-IR) spectroscopy, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, differential scanning calorimetry and gel permeation chromatography. Monosaccharide sugar analysis revealed that the gum is composed of glucose, rhamnose, galactose, arabinose and xylose as the main neutral sugars. These were supported by the results from 1H and 13C NMR spectroscopic analysis. FT-IR and solid-state NMR results indicated that drying technique has little effect on the structure of the polysaccharide gum but XPS showed that surface chemistry of the gum varied with drying methods. Thermogravimetric analyses showed that oxidation onset varied according to the drying method. The molecular weight was also dependent on the drying technique. For industrial extrapolation, air-drying may be preferable to spray-drying and freeze-drying when relative cost, product stability and powder flow are required, for example in tablet formulation. © 2010 Elsevier Ltd. All rights reserved.

Combined quality function deployment and logical framework analysis to improve quality of emergency care in Malta

Purpose – The purpose of this paper is to develop an integrated patient-focused analytical framework to improve quality of care in accident and emergency (A&E) unit of a Maltese hospital. Design/methodology/approach – The study adopts a case study approach. First, a thorough literature review has been undertaken to study the various methods of healthcare quality management. Second, a healthcare quality management framework is developed using combined quality function deployment (QFD) and logical framework approach (LFA). Third, the proposed framework is applied to a Maltese hospital to demonstrate its effectiveness. The proposed framework has six steps, commencing with identifying patients’ requirements and concluding with implementing improvement projects. All the steps have been undertaken with the involvement of the concerned stakeholders in the A&E unit of the hospital. Findings – The major and related problems being faced by the hospital under study were overcrowding at A&E and shortage of beds, respectively. The combined framework ensures better A&E services and patient flow. QFD identifies and analyses the issues and challenges of A&E and LFA helps develop project plans for healthcare quality improvement. The important outcomes of implementing the proposed quality improvement programme are fewer hospital admissions, faster patient flow, expert triage and shorter waiting times at the A&E unit. Increased emergency consultant cover and faster first significant medical encounter were required to start addressing the problems effectively. Overall, the combined QFD and LFA method is effective to address quality of care in A&E unit. Practical/implications – The proposed framework can be easily integrated within any healthcare unit, as well as within entire healthcare systems, due to its flexible and user-friendly approach. It could be part of Six Sigma and other quality initiatives. Originality/value – Although QFD has been extensively deployed in healthcare setup to improve quality of care, very little has been researched on combining QFD and LFA in order to identify issues, prioritise them, derive improvement measures and implement improvement projects. Additionally, there is no research on QFD application in A&E. This paper bridges these gaps. Moreover, very little has been written on the Maltese health care system. Therefore, this study contributes demonstration of quality of emergency care in Malta.