STABILITY FOR RETARDED FUNCTIONAL DIFFERENTIAL EQUATIONS

It is known that retarded functional differential equations can be regarded as Banach-space-valued generalized ordinary differential equations (GODEs). In this paper, some stability concepts for retarded functional differential equations are introduced and they are discussed using known stability results for GODEs. Then the equivalence of the different concepts of stabilities considered here are proved and converse Lyapunov theorems for a very wide class of retarded functional differential equations are obtained by means of the correspondence of this class of equations with GODEs.

Interaction of horseradish peroxidase with Langmuir monolayers of phospholipids

The method employed to incorporate guest molecules onto phospholipid Langmuir monolayers plays an important role in the interaction between the monolayer and the guest molecules. In this paper, we show that for the interaction between horseradish peroxidase (HRP) and a monolayer of dipalmitoylphosphatidylglycerol (DPPG) does depend on the method of HRP incorporation. The surface pressure isotherms of the mixed DPPG/HRP monolayers, for instance, were less expanded when the two materials were co-spread than in the case where HRP was injected into the subphase. Therefore, the method for incorporation affected not only the penetration of HRP but also the changes in molecular packing caused to the DPPG monolayer. With experiments with the monolayer on a pendant drop, we observed that the incorporation of HRP affects the dynamic elasticity of the DPPG monolayer, on a way that varies with the surface pressure. At low pressures, HRP causes the monolayer to be more rigid, while the converse is true for surface pressures above 8 mN/m. Taken all the results together, we conclude that HRP is more efficiently incorporated if injected into the subphase on which a DPPG monolayer had been spread and that the interaction between HRP and DPPG is maintained even at high surface pressures. This is promising for the possible transfer of mixed films onto solid substrates and for applications in biosensors and drug delivery systems. (c) 2008 Elsevier B.V. All rights reserved.

El cambio de código en hispanohablantes en Suecia : Experiencias y actitudes

In this thesis it is investigated how Spanish-speakers in Sweden experience living with two languages ​​and how common it is for them to use code-switching in their everyday speech. The study has focused on not only the experiences but also the use of code-switching among Hispanics who have become bilinguals in Sweden. The study has also examined the attitudes the informants show towards code – switching.The aim of this study is to provide a picture of the experiences Spanish-speakers have of becoming bilinguals in Sweden and of learning and using Swedish as a second language. It is of interest to see how the bilinguals converse inside and outside the home and how frequent and accepted it is among the Hispanics in Sweden with the use of code-switching in different social contexts. In summary, we can see that the Hispanics in Sweden are satisfied with the linguistic development they have experienced by learning a new language and that they consider it beneficial being bilingual. The study shows that code-switching is very much used, but not fully accepted even by those who use it on a daily basis. Code-switching is in many cases not considered appropriate and it is sometimes performed unconsciously.

Estimating demolition costs for single residential buildings

With the increasing stock of aging structures, building
demolition is becoming achallenging research field from
the perspective of management. As the converse of
construction, management of demolition puts forward some
new management themes or adds some new contents
even though the same issues are faced in construction
management. This research aims to develop a quantitative
approach to estimate the costs of a demolition project. A
cost analysis method is presented to systematically break
down the cost components involved in the demolition of
a structure. Due to the lack of robust research in theory
and systematic summary in practice to date, the economic
performances of demolition will be studied through acase
study, and the majority of parameters are derived from
actual experiences in practice. The proposed demolition cost
estimation method is applied to the actual form of building
elimination (Scenario 1), and further comparison is carried
out with two other elimination methods, which are the newly
developed deconstruction (Scenario 2) and mechanical
demolition (Scenario 3). Deconstruction is found to be the
most profitable in this particular instance, and is closely
followed by the actual form.

Poets in dialogue, dialogues in poets

Is there something noticeably peculiar about dialogues with poets when transformed into writing, be it in electronic or printed form? The pauses and hesitations, the thrust and parry, the slurrings and overlappings of ordinary speech by and large disappear. In their place is an artifice, a deliberate creation of a script, with questions and responses clearly marked for our attention. Might we be approaching a tidied duologue which, some might also cynically remark, largely reproduces a dual monologue? Moreover, when poets are in dialogue, with whom or what does the poet converse?

Touch it, feel it and experience it: developing professional IS skills using interview-style experiential simulations

The IS education field has made increasing use of computerised experiential simulations, but few attempts have been made to create an authentic learning environment that combines and balances elements of video-based computer simulation with real-life learning activities. This paper explores the design principles used to develop a CD-ROM simulation where learners use interviewing skills to elicit system requirements from simulated employees in an authentic context. The employees are videoed actors who converse with each other and with learners within a dynamic interaction model. The paper also describes how we combined this simulation with other teaching approaches such as in-class discussions, student team work, formal presentations, etc.

Modeling and analyses of the retirement of deteriorated structures

With the increasing stock of aging structures, the strategy to model and analyse the retirement of deteriorated structures is becoming a challenging research field. As the converse of construction of new projects, the retirement of constructed facilities puts forward some new management and economics themes as well as environmental issues or adds some new contents even though the same issues are faced in construction. This research aims to model and analyse the maintenance and demolition activities of constructed facilities from economic and environmental perspectives. Both cost and carbon dioxide of maintenance and demolition activities are formulated based on those of construction activities and applied to an empirical study on deteriorated bridges. Further modelling and analysis is investigated to elaborate the demolition stage of a structure. The developed modelling and analysis methodology may enable the decision maker to determine the retirement strategy for a deteriorated structure.

"Where myth becomes history" : the politics of mythical time in Heiner Muller's Medea

Heiner Müller in the 1980s produced a sequence of plays featuring Euripides’ heroine Medea using his distinctive, poetic modality of “the theatre of images”. These ostensibly postmodern narratives take the form of disjointed, visual and textual representations that are also fragmentations of historical and mythical times and spaces. Müller’s Medea plays are thus suggestive of the intersection between the discourses of history and myth — and the blending of historical time with ahistorical, supposedly “timeless” mythical narratives. Further, the postmodern possibility of history’s textuality to liquidate it into a type of (modern) mythology seeks expression in the plays’ representation of a converse equation: the moment signaled in the text as that “where myth becomes history”. This paper examines the problematisation of the myth-history dichotomy in Müller’s Medea plays, outlining the ways in which the “timeless” myth of the classical, infanticidal figure of Medea is strategically deployed to politicise evolutionist teleology, Western colonialism and the technologies of war in twentieth century Europe.

Stability theory and numerical analysis of non-autonomous dynamical systems

The development and use of cocycles for analysis of non-autonomous behaviour is a technique that has been known for several years. Initially developed as an extension to semi-group theory for studying rion-autonornous behaviour, it was extensively used in analysing random dynamical systems [2, 9, 10, 12]. Many of the results regarding asymptotic behaviour developed for random dynamical systems, including the concept of cocycle attractors were successfully transferred and reinterpreted for deterministic non-autonomous systems primarily by P. Kloeden and B. Schmalfuss [20, 21, 28, 29]. The theory concerning cocycle attractors was later developed in various contexts specific to particular classes of dynamical systems [6, 7, 13], although a comprehensive understanding of cocycle attractors (redefined as pullback attractors within this thesis) and their role in the stability of non-autonomous dynamical systems was still at this stage incomplete. It was this purpose that motivated Chapters 1-3 to define and formalise the concept of stability within non-autonomous dynamical systems. The approach taken incorporates the elements of classical asymptotic theory, and refines the notion of pullback attraction with further development towards a study of pull-back stability arid pullback asymptotic stability. In a comprehensive manner, it clearly establishes both pullback and forward (classical) stability theory as fundamentally unique and essential components of non-autonomous stability. Many of the introductory theorems and examples highlight the key properties arid differences between pullback and forward stability. The theory also cohesively retains all the properties of classical asymptotic stability theory in an autonomous environment. These chapters are intended as a fundamental framework from which further research in the various fields of non-autonomous dynamical systems may be extended. A preliminary version of a Lyapunov-like theory that characterises pullback attraction is created as a tool for examining non-autonomous behaviour in Chapter 5. The nature of its usefulness however is at this stage restricted to the converse theorem of asymptotic stability. Chapter 7 introduces the theory of Loci Dynamics. A transformation is made to an alternative dynamical system where forward asymptotic (classical asymptotic) behaviour characterises pullback attraction to a particular point in the original dynamical system. This has the advantage in that certain conventional techniques for a forward analysis may be applied. The remainder of the thesis, Chapters 4, 6 and Section 7.3, investigates the effects of perturbations and discretisations on non-autonomous dynamical systems known to possess structures that exhibit some form of stability or attraction. Chapter 4 investigates autonomous systems with semi-group attractors, that have been non-autonomously perturbed, whilst Chapter 6 observes the effects of discretisation on non-autonomous dynamical systems that exhibit properties of forward asymptotic stability. Chapter 7 explores the same problem of discretisation, but for pullback asymptotically stable systems. The theory of Loci Dynamics is used to analyse the nature of the discretisation, but establishment of results directly analogous to those discovered in Chapter 6 is shown to be unachievable. Instead a case by case analysis is provided for specific classes of dynamical systems, for which the results generate a numerical approximation of the pullback attraction in the original continuous dynamical system. The nature of the results regarding discretisation provide a non-autonomous extension to the work initiated by A. Stuart and J. Humphries [34, 35] for the numerical approximation of semi-group attractors within autonomous systems. . Of particular importance is the effect on the system's asymptotic behaviour over non-finite intervals of discretisation.

Spurious precision : variability in procedural validity of diagnostic procedures in psychotic disorders and implications for research and treatment

Very few studies have quantified the level of agreement among alternative diagnostic procedures that use a common set of fixed operational criteria. The authors examined the procedural validity of four independent methods of assigning DSM-III-R diagnoses of psychotic disorders. METHOD: The research was conducted as a satellite study to the DSM-IV Field Trial for Schizophrenia and Related Psychotic Disorders. The setting was the National Health and Medical Research Council Schizophrenia Research Unit's Early Psychosis Prevention and Intervention Centre, which focuses on first-episode psychosis. Consecutively admitted patients (N = 50) were assessed by independent raters who used four different procedures to determine a DSM-III-R diagnosis. These procedures were 1) the diagnostic instrument developed for the DSM-IV field trial, 2) the Royal Park Multidiagnostic Instrument for Psychosis, 3) the Munich Diagnostic Checklists, and 4) a consensus DSM-III-R diagnosis assigned by a team of clinician researchers who were expert in the use of diagnostic criteria. RESULTS: Concordance between pairs of diagnostic procedures was only moderate. Corresponding levels of percent agreement, however, ranged from 66% to 76%, with converse misclassification rates of 24%-34% (assuming one procedure to be "correct"). CONCLUSIONS: These findings have significant research and clinical implications. Despite the introduction of operationally defined diagnoses, there remained an appreciable level of differential classification or misclassification arising from variability in the method of assigning the diagnostic criteria rather than the criteria themselves. Such misclassification may impede neurobiological research and have harmful clinical effects on patients with first-episode psychosis.

Dopamine dysregulation syndrome : implications for a dopamine hypothesis of bipolar disorder

Objective: Rational therapeutic development in bipolar is hampered by a lack of pathophysiological model. However, there is a wealth of converging data on the role of dopamine in bipolar disorder. This paper therefore examines the possibility of a dopamine hypothesis for bipolar disorder.

Method: A literature search was conducted using standard search engines Embase, PyschLIT, PubMed and MEDLINE. In addition, papers and book chapters known to the authors were retrieved and examined for further relevant articles.

Results: Collectively, in excess of 100 articles were reviewed from which approximately 75% were relevant to the focus of this paper.

Conclusion: Pharmacological models suggest a role of increased dopaminergic drive in mania and the converse in depression. In Parkinson’s disease, administration of high-dose dopamine precursors can produce a ‘maniform’ picture, which switches into a depressive analogue on withdrawal. It is possible that in bipolar disorder there is a cyclical process, where increased dopaminergic transmission in mania leads to a secondary down regulation of dopaminergic receptor sensitivity over time. This may lead to a period of decreased dopaminergic transmission, corresponding with the depressive phase, and the repetition of the cycle. This model, if verified, may have implications for rational drug development.

Blood pressure modifies retinal susceptibility to intraocular pressure elevation

Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP) is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP). An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine) Long-Evan rats with low (~60 mmHg, sodium nitroprusside infusion), moderate (~100 mmHg, saline), or high levels (~160 mmHg, angiotensin II) of mean arterial pressure (MAP, n = 5–10 per group) were subjected to IOP challenge (10–120 mmHg, 5 mmHg steps every 3 minutes). Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave) and inner retinal function (scotopic threshold response or STR). Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.

Literary conversations: an Australian classroom

Teachers listen attentively to the classroom conversations in which their students engage. This often involves delicate judgments about whether to stay silent or intervene. Should I move the discussion along by asking a question or making a comment? Or would it be better to allow the conversation to continue, however awkwardly the students might be expressing their insights? Awkward or not, there is value in providing opportunities for young people to find the words they need in order to converse with one another in classroom settings, building on each other’s sentences in an effort to jointly construct meaning and reach understanding.

The War Memoirs: Some origins of the thought of W.R. Bion

The work of W. R. Bion changed the shape of psychoanalytic theory in fundamental ways, one of the most important of which was Bion's insight into the nature of normal projective identification. No other psychoanalytic theorist has Bion's ability to represent the horrors of psychic abandonment and the converse, the absolute necessity of the presence of another mind for psychic survival. Through a discussion of Bion's War Memoirs 1917-1919 (Bion, 1997), Attacks on linking and A theory of thinking (1993), this paper explores the link between war, masculinity, the maternal and Bion's sensitivity to the significance of everyday interpersonal contact. It is argued that Bion's apocalyptic experiences as a teenage tank commander gave him shattering insight into the extent to which mind is inter-mind, self is inter-self. Bion's life writing has the quality of survivor insight: 'And only I am escaped alone to tell thee' (Job 1: 14-19), as he returns repeatedly to the events of the day when he 'died ', 8 August 1918. His insight into the elemental passions nature of love, hate and mindlessness are borne of his experiences on the battlefield, and exquisitely crystallized in his repeated explorations of an encounter with a dying soldier.

Some properties of finite-time stable stochastic nonlinear systems

In this paper we study some properties of finite-time stable stochastic nonlinear systems. We begin by showing several continuous dependence theorems of solutions on initial values under some conditions on the coefficients of stochastic systems. We then derive some regular properties of its stochastic settling time for a finite-time stable stochastic nonlinear system. We show continuity, positive definiteness and boundedness of the expected stochastic settling time under appropriate conditions. Finally, a Lyapunov function is constructed by making use of the expectation of the stochastic settling time, and the infinitesimal generator of the stochastic system defined on the Lyapunov function is also given, and hence resulting in a converse Lyapunov theorem of finite-time stochastic stability.