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Autofocus for ISAR Imaging Using Higher Order Statistics
Get PDFAutofocus is imperative for inverse synthetic aperture radar (ISAR) imaging. In this letter, a new approach for ISAR autofocus is developed by using fourth-order statistics properties of the radar’s return signal. After the ISAR signal model is established, the approach is described. The results of processing real data confirm the effectiveness of the proposed approach and show its capability for suppressing noise. The developed approach has a numerical stability and a smaller computational load compared with the maximum image contrast and the minimum image entropy methods
Virtual Backbone Configuration in Wireless Mesh Networks
Get PDFThis paper introduces methods for the minimisation of virtual backbone size in wireless mesh networks, subject to practical constraints. The methods are centralised, which limits their usage to static applications. Four algorithms are presented, one exact and three heuristic. The exact method guarantees to find an optimal solution but runs in exponential time. Of the three heuristics, one is shown to match the performance of the optimal algorithm for all problem instances tested. The problem is constrained to introduce potentially massive levels of redundancy into the network topology, making the designs survivable
On Positive Psychological Outcomes: What Helps Groups With a History of Conflict to Forgive and Reconcile With Each Other?
No full textThree studies examined the roles of traditional and novel social psychological variables involved in intergroup forgiveness. Study 1 (N = 480) revealed that among the pro-Pinochet and the anti-Pinochet groups in Chile, forgiveness was predicted by ingroup identity (negatively), common ingroup identity (positively), empathy and trust (positively), and competitive victimhood (the subjective sense of having suffered more than the outgroup, negatively). Political ideology (Right vs. Left) moderated the relationship between empathy and forgiveness, trust and forgiveness, and between the latter and competitive victimhood. Study 2 (N = 309), set in the Northern Irish conflict between Protestants and Catholics, provided a replication and extension of Study 1. Finally, Study 3 (N = 155/108) examined the longitudinal relationship between forgiveness and reconciliation in Northern Ireland, revealing that forgiveness predicted reconciliation intentions. The reverse direction of this relationship was also marginally significant. Results are discussed in terms of their theoretical and practical implications
Determination of the calorific value of gum Arabic in rats using modified versions of the growth bioassay and the digestibility assay
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Empirical theology: a natural development?
Get PDFEmpirical theology is distinguished from practical theology by reference to the views of Duncan Forrester and J van der Ven. The nature and historical emergence of theological disciplines are considered and related to the social science methods found in van der Ven’s account of empirical theology. Such social science methods are congruent with those used in natural sciences and therefore in natural theology. Empirical theology may be variously located within the whole enterprise of theology. Yet, it belongs in the theological fold by virtue of its relation to natural theology and through the historical trajectory by which the subdisciplines of theology have come into being
Chain scission of hyaluronan by carbonate and dichloride radical anions: Potential reactive oxidative species in inflammation?
No full textThe reactions of the carbonate and dichloride radical anions, CO3− and Cl2−, with the extracellular matrix glycosaminoglycan hyaluronan (HA) have been studied using the kinetic technique of pulse radiolysis and also by steady-state irradiation combined with gel permeation chromatography/multiangle laser light scattering(gpc/MALLS) to measure the rates of reaction with HA and the yield of HA chain scission, respectively. For comparison, the same measurements were made for the reactions of the free radicals OH, Br2−, and N3. The carbonate and dichloride radical anions were found to react relatively quickly with HA (7.0 × 105 and 6.9 × 106 dm3 mol−1 s−1, respectively) although they are much less reactive than the hydroxyl radical, OH. Significant yields (20 and 38%, respectively) of chain scission of HA by these radical anions were also determined from the gpc/MALLS experiments, providing some support for their potential participation in the depolymerization of HA in vivo. These results are compared with data obtained for the other free radicals (hydroxyl, azide radicals, and dibromide radical anions) investigated in this study in order to gain an insight into their mechanism of reaction with HA. Earlier chain scission yields of HA by hydroxyl radicals determined by the authors have also been revised using the gpc/MALLS technique employed in the current study. The yields of 52% (absence of air) and 44% (in air) are much lower than the previous values. In the current study, the effect of oxygen on the yields of HA chain breaks is discussed in terms of the reactivity of HA peroxyl radicals in the presence of superoxide radical anions. The relevance of the results of this study to mechanisms of inflammation is discussed
Characterization and properties of Acacia senegal (L.) Willd. var. senegal with enhanced properties (Acacia (sen) SUPER GUM™): Part 1—Controlled maturation of Acacia senegal var. senegal to increase viscoelasticity, produce a hydrogel form and convert a poor into a good emulsifier
No full textThe Acacia gum (Acacia senegal var. senegal), which is a food additive approved by Codex Alimentarius, is defined within the Acacia subgenus (family Leguminosae). The structural characteristics associated with a “poor” and “good” emulsifying A. senegal var. senegal exudate gum are identified and it is shown that it is possible to maturate the “poor” emulsifier in a process comparable to that which occurs to the exudate gum as the age of the tree increases from 1 to 15 years and when the gum is stored naturally after collection. Thus, the molecular parameters of the “good” gum can be matched, and the emulsification effectiveness can attain the level of the “good” emulsifier. The process can be further continued to produce a series of gums of precisely structured molecular dimensions with improved properties and if the maturation is continued can yield a hydrogel form of Acacia. The new forms of A. senegal which are described here, and which have not previously been available are designated Acacia (sen) SUPER GUM™ which are constant in properties and with precisely structured molecular dimensions, unlike the naturally occurring gum. The viscosity can be increased up to 20 times compared to the starting material. The controlling factor is the agglomeration of the proteinaceous components within the molecularly disperse system that is A. senegal gum to increase the amount of arabinogalactan protein (AGP) emulsifying component up to more than double the amount present originally. This results in a dramatic increase in the interfacial surface properties and coverage of the oil droplet in oil in water emulsion. No other chemical change is initiated by the maturation process
Religious orientation, religious coping and happiness among UK adults
No full textIt has been demonstrated that the relationship between religiosity and happiness varies according to the precise measures used and the samples studied. To examine further the generalisability of this association the present work examined the relationship between religiosity and happiness within the context of the distinction between subjective and psychological well-being. One hundred and thirty eight UK adults completed two measures of both religiosity (the ‘Age Universal’ Religious Orientation Scale [Intrinsic and Extrinsic subscales] and the Religious Coping Scale [Positive and Negative subscales]) and happiness (the Depression–Happiness Scale and the Oxford Happiness Questionnaire Short-Form). In general, no significant associations were found between religiosity scores and happiness scores. However, both higher intrinsic orientation scores and positive religious coping were significantly associated with higher scores on the Oxford Happiness Questionnaire Short-Form. It is proposed that these differential findings are consistent with the theoretical distinction between subjective and psychological well-being. It is suggested that when religiosity is related to happiness, it is related to psychological well-being, which is thought to reflect human development, positive functioning and existential life challenges
Visualising the Invisible’: Arts and Science Collaboration
Get PDFThis research explores, psychoanalyst/linguist/philosopher, Julia Kristeva’s concept that female subjectivity seems linked to both cyclical time (menstruation/pregnancy/repetition) and monumental time in sense of eternity (motherhood/reproduction/genetic chain). Whilst also investigating ‘psychological resonance,’ a particular part of the creative process that conjures up the idea of movement between something experienced (object) and it’s impact on the individual (subject). Heald and Liggett are developing ideas relating to a ‘space’ an ‘in-between-ness’ and ‘cyclical time’ from an art/science perspective. Heald began exploring Kristeva’s notion of the semiotic chora as a preverbal space that relates to rhythms, colours and trace, the preverbal infant, the depressive and the psychotic. She became interested in the aspect of the unconscious/subconcious, through working with the patients, exploring maternal/cyclical/monumental time, poetics and the chora. Through ‘dream films’ she creates ambient environments, where the audience is unsure as to whether one is asleep/awake, or even in a state of ‘in-between-ness’. Liggett found ‘in-between-ness’ relates to the stage in the creative process where the artists in her research could not articulate in words exactly what they were intending in their work. The dream state described as occupying ‘in-between-ness’ could also be akin to ‘psychological resonance’, the movement between ‘sites' or 'states of being', that exists, but are intangible and difficult to articulate. Exploring Winnicott (1994) and Witkin (1974) Liggett suggests that there are three areas of related experience, the subjective, the objective and what Winnicott calls 'potential space'. This 'potential space' Liggett sees as having similarities to ‘in-between-ness’. Heald and Liggetts work at the hospital only enabled the artist’s access to patients who are on/adjusting to medication. Building upon the work being completed at the psychiatric unit and in collaboration with Dr Richard Tranter, consultant psychiatrist, Prof. Rob Poole, Professor of Mental Health and GP surgeries, Heald and Liggett are proposing new perspectives into the effects of anti-depressant medications. Scientists know that antidepressants subtly alter the way people perceive emotional stimuli around them, altering people’s social behaviour’s, on a level that people are not consciously aware of. Through arts/science research the collaborators are interested to explore if patient changes are reflected in the way people express themselves and respond to their environment, prior, during and post antidepressant medication. The collaborative arts/science practice will explore these interests through creative, patient lead, artistic expressions of change alongside conventional, reductionist measures of changing depressive symptoms (Beck Depression Inventory) producing sophisticated fusions of art/science
Magnetophoretic assembly and printing of nanowires
Get PDFNanowires are a well-established class of materials covering both metals and semiconductors. Although the synthesis of nanowires has been highly developed, their manipulation into specific device structures has lagged behind. Here we report a simple room temperature method for creating directly patterned structures out of nickel nanowires of submicron diameters as previously formed by electrotemplating. Specially shaped magnetic pole-pieces are used to form patterns of these ferromagnetic rods on thin flexible plastic foils, which were then fixed permanently into place either by electrodepositing an additional thin nickel coating or by a UV-curable polymer solution. It is shown that it is possible with oriented and patterned magnetic fields to create both vertically and, by using additional surface tension forces upon drying, horizontally aligned arrays of nickel rods. The authors show that linewidths down to 50 μm can easily be realized with this technique and also show that direct printing of these magnetophoretically assembled structures onto adhesive or rubber substrates is also possible. The simplicity and low-cost inherent in this lithography-free method suggests that it is suitable as a general manufacturing method for nanowire assembly. As an example, a simple field emission display device is demonstrated