Theory of Non-linear Waves in Multi-dimensions: with Special Reference to Surface Water Waves

The surface water waves are "modal" waves in which the "physical space" (t, x, y, z) is the product of a propagation space (t, x, y) and a cross space, the z-axis in the vertical direction. We have derived a new set of equations for the long waves in shallow water in the propagation space. When the ratio of the amplitude of the disturbance to the depth of the water is small, these equations reduce to the equations derived by Whitham (1967) by the variational principle. Then we have derived a single equation in (t, x, y)-space which is a generalization of the fourth order Boussinesq equation for one-dimensional waves. In the neighbourhood of a wave froat, this equation reduces to the multidimensional generalization of the KdV equation derived by Shen & Keller (1973). We have also included a systematic discussion of the orders of the various non-dimensional parameters. This is followed by a presentation of a general theory of approximating a system of quasi-linear equations following one of the modes. When we apply this general method to the surface water wave equations in the propagation space, we get the Shen-Keller equation.

Co-Signaling by Neurotrophic Factors and the Extracellular Matrix for Axonal Growth and Neuronal Survival

Neurotrophic factors (NTFs) and the extracellular matrix (ECM) are important regulators of axonal growth and neuronal survival in mammalian nervous system. Understanding of the mechanisms of this regulation is crucial for the development of posttraumatic therapies and drug intervention in the injured nervous system. NTFs act as soluble, target-derived extracellular regulatory molecules for a wide range of physiological functions including axonal guidance and the regulation of programmed cell death in the nervous system. The ECM determines cell adhesion and regulates multiple physiological functions via short range cell-matrix interactions. The present work focuses on the mechanisms of the action of NTFs and the ECM on axonal growth and survival of cultured sensory neurons from dorsal root ganglia (DRG). We first examined signaling mechanisms of the action of the glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) on axonal growth. GDNF, neurturin (NRTN) and artemin (ART) but not persephin (PSPN) promoted axonal initiation in cultured DRG neurons from young adult mice. This effect required Src family kinase (SFK) activity. In neurons from GFRalpha2-deficient mice, NRTN did not significantly promote axonal initiation. GDNF and NRTN induced extensive lamellipodia formation on neuronal somata and growth cones. This study suggested that GDNF, NRTN and ARTN may serve as stimulators of nerve regeneration under posttraumatic conditions. Consequently we studied the convergence of signaling pathways induced by NTFs and the ECM molecule laminin in the intracellular signaling network that regulates axonal growth. We demonstrated that co-stimulation of DRG neurons with NTFs (GDNF, NRTN or nerve growth factor (NGF)) and laminin leads to axonal growth that requires activation of SFKs. A different, SFK-independent signaling pathway evoked axonal growth on laminin in the absence of the NTFs. In contrast, axonal branching was regulated by SFKs both in the presence and in the absence of NGF. We proposed and experimentally verified a Boolean model of the signaling network triggered by NTFs and laminin. Our results put forward an approach for predictable, Boolean logics-driven pharmacological manipulation of a complex signaling network. Finally we found that N-syndecan, the receptor for the ECM component HB-GAM was required for the survival of neonatal sensory neurons in vitro. We demonstrated massive cell death of cultured DRG neurons from mice deficient in the N-syndecan gene as compared to wild type controls. Importantly, this cell death could not be prevented by NGF the neurotrophin which activates multiple anti-apoptotic cascades in DRG neurons. The survival deficit was observed during first postnatal week. By contrast, DRG neurons from young adult N-syndecan knock-out mice exhibited normal survival. This study identifies a completely new syndecan-dependent type of signaling that regulates cell death in neurons.

Nonlinear secondary whirl of an overhung rotor

Gravity critical speeds of rotors have hitherto been studied using linear analysis, and ascribed to rotor stiffness asymmetry. Here, we study an idealized asymmetric nonlinear overhung rotor model of Crandall and Brosens, spinning close to its gravity critical speed.Nonlinearities arise from finite displacements, and the rotor's staticlateral deflection under gravity is taken as small. Assuming small asymmetry and damping, slow modulations of whirl amplitudes are studied using the method of multiple scales. Inertia asymmetry appears only at second order. More interestingly, even without stiffness asymmetry, the gravity-induced resonance survives through geometric nonlinearities. The gravity resonant forcing does not influence the resonant mode at leading order, unlike the typical resonant oscillations. Nevertheless,the usual phenomena of resonances, namely saddle-node bifurcations, jump phenomena and hysteresis, are all observed. An unanticipated periodic solution branch is found. In the three-dimensional space oftwo modal coefficients and a detuning parameter, the full set of periodic solutions is found to be an imperfect version of three mutually intersecting curves: a straight line,a parabola and an ellipse.

Clinical application of biomarkers in prostate cancer in men with metabolic syndrome project: Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in diagnosing localised prostate cancer

Localised prostate cancer is a heterogenous disease and a multi-modal approach is required to accurately diagnose and stage the disease. Whilst the use of magnetic resonance imaging (MRI) has become more common, small volume and multi-focal disease are oft en diffi cult to characterise. Prostate specifi c membrane antigen is a cell surface protein, which is expressed in nearly all prostate cancer cells. Its expression is signifi cantly higher in high grade prostate cancer cells. In this study, we compare multi-parametric magnetic resonance imaging and 68-Gallinium-PSMA PET with whole-mount pathology of the prostate to evaluate the applicability of multiparameteric (MP) MRI and 68Ga-PSMA PET in detecting and locating tumour foci in patients with localised prostate cancer.

Vibration characteristics and damage detection in a suspension bridge

Suspension bridges are flexible and vibration sensitive structures that exhibit complex and multi-modal vibration. Due to this, the usual vibration based methods could face a challenge when used for damage detection in these structures. This paper develops and applies a mode shape component specific damage index (DI) to detect and locate damage in a suspension bridge with pre-tensioned cables. This is important as suspension bridges are large structures and damage in them during their long service lives could easily go un-noticed. The capability of the proposed vibration based DI is demonstrated through its application to detect and locate single and multiple damages with varied locations and severity in the cables of the suspension bridge. The outcome of this research will enhance the safety and performance of these bridges which play an important role in the transport network.

Tribology of steel/steel interaction in oil-in-water mulsion; a rationale for lubricity

Oil droplets are dispersed in water by an anionic urfactant to form an emulsion. The lubricity of this emulsion in steel/steel interaction is explored in a ball on flat nanotribometer. The droplet size and charge are measured using dynamic light scattering, while the substrate charge density is estimated using the pH titration method. These data are combined to calculate the DLVO forces for the droplets generated for a range of surfactant concentration and two oil to water volume ratios. The droplets have a clear bi-modal size distribution. The study shows that the smaller droplets which experience weak repulsion are situated (at the highest DLVO barrier) much closer to the substrate than thebigger droplets, which experience the same DLVO force, are. We suggest that the smaller droplets thus play a more important role in lubricity than what the bigger droplets do. The largest volume of such small droplets occurs in the 0.5 mM-1 mM range of surfactant concentration and 1% oil to water volume ratio, where the coefficient of friction is also observed to be the least. (C) 2010 Elsevier Inc. All rights reserved.

Kulutus, tieto, hallinta : Kulutuksen tilastoinnin muutokset 1900-luvun Suomessa

The aim of the study was to find out how the consumption of the population in Finland became a target of social interest and production of statistical data in the early 20th century, and what efforts have been made to influence consumption with social policy measures at different times. Questions concerning consumption are examined through the practices employed in the compilation of statistics on it. The interpretation framework in the study is Michael Foucault s perspective of modern liberal government. This mode of government is typified by pursuit of efficiency and search of equilibrium between economic government and a government of the processes of life. It shows aspirations towards both integration and individualisation. The government is based on freedom practices. It also implies knowledge-based ways of conceptualising reality. Statistical data are of specific significance in this context. The connection between the government of consumption and the compilation of statistics on it is studied through the theoretical, socio-political and statistical conceptualisation of consumption. The research material consisted of Finnish and international documentation on the compilation of statistics on consumption, publications of social programmes, and reports of studies on consumption. The analysis of the material focused especially on the problematisations related to consumption found in these documents and on changes in them over history. There have been both clearly observable changes and as well as historical stratification and diversity in the rationalities and practices of consumption government during the 20th century. Consumption has been influenced by pluralistic government, based at different times and in varying ways on the logics of solidarity and markets. The difference between these is that in the former risks are prepared for collectively while in the latter risks are individualised. Despite the differences, the characteristic that is common to these logics is certain kind of contractuality. They are both permeated by the household logic which differs from them in that it is based on the normative and ethical demands imposed on an individual. There has been a clear interactive connection between statistical data and consumption government. Statistical practices have followed changes in the way consumption has been conceptualised in society. This has been reflected in the statistical phenomena of interest, concepts, classifications and indicators. New ways of compiling statistics have in their turn shaped perceptions of reality. Statistical data have also facilitated a variety of rational calculations with which the consequences of the population s consumption habits have been evaluated at the levels of economy at large and individuals.

The EU and Institutional Twinning in Morocco - An inquiry into the motives of cooperation through discourse ethics

This study examines Institutional Twinning in Morocco as a case of EU cooperation through the pragmatic, ethical and moral logics of reason in Jürgen Habermas’s discourse ethics. As a former accession tool, Twinning was introduced in 2004 for legal approximation in the context of the European Neighborhood Policy. Twinning is a unique instrument in development cooperation from a legal perspective. With its long historical and cultural ties to Europe, Morocco presents an interesting case study of this new form of cooperation. We will analyse motives behind the Twinning projects on illegal immigration, environment legislation and customs reform. As Twinning is a new policy instrument within the ENP context, there is relatively little preceding research, which, in itself, constitutes a reason to inquire into the subject. While introducing useful categories, the approaches discussing “normative power Europe” do not offer methodological tools precise enough to analyse the motives of the Twinning cooperation from a broad ethical standpoint. Helene Sjursen as well as Esther Barbé and Elisabeth Johansson-Nogués have elaborated on Jürgen Habermas’ discourse ethics in determining the extent of altruism in the ENP in general. Situating the analysis in the process-oriented framework of Critical Theory, discourse ethics provides the methodological framework for our research. The case studies reveal that the context in which they operate affects the pragmatic, ethical and moral aspirations of the actors. The utilitarian notion of profit maximization is quite pronounced both in terms of the number of Twinning projects in the economic sphere and the pragmatic logics of reason instrumental to security and trade-related issues. The historical background as well internal processes, however, contribute to defining areas of mutual interest to the actors as well as the motives Morocco and the EU sometimes described as the external projection of internal values. Through its different aspects, Twinning cooperation portrays the functioning of the pragmatic, ethical and moral logics of reason in international relations.

Reconciling Opposites in Organisation Studies: An Aristotelian Approach to Modernism and Post-modernism

In view of the current fragmentation in management and organisation studies, we argue that there is a need to elaborate techniques that help reconcile contradictory and superficially incommensurable standpoints. For this purpose, we draw on ‘pre-modern’ Aristotelian epistemological and methodological sources, particularly the idea of ‘saving the appearances’ (SA), not previously introduced into organisation studies. Using SA as our starting point, we outline a methodology that helps to develop reasonable and acceptable intermediary positions in contemporary debates between ‘modernism’ and ‘post-modernism’. We illustrate the functioning of SA in the case of three issues in the philosophy of science where ‘modernist’ and ‘post-modernist’ scholars seem to have incommensurable standpoints: the nature of scientific knowledge; the conception of causality; and the epistemology of practice. We show in particular how to use the logics of ‘qualification’, ‘new conception’, and ‘complementary combination’ to form the basis for mediating positions which could then be accepted by less extreme proponents of both ‘modernism’ and ‘postmodernism’.

Natural modes of a coupled non-linear system

The natural modes of a non-linear system with two degrees of freedom are investigated. The system, which may contain either hard or soft springs, is shown to possess three modes of vibration one of which does not have any counterpart in the linear theory. The stability analysis indicates the existence of seven different modal stability patterns depending on the values of two parameters of non-linearity.

Personnel Managers and Crisis Situations. Emotion-handling Strategies

This study focuses on personnel managers in crisis situations. The interviewed personnel managers referred to emotions as a central element to be dealt with in a crisis. However, until recently, the exploration of emotions in organisational life has been de-emphasised or ignored. This study aims to bring to the surface aspects of personnel work that have so far been neglected or remained invisible. It specifically examines how personnel managers handle employees’ and their own emotions in a crisis. Based on the interviews, a number of emotional episodes were constructed. They describe the type and context of the crisis and the person(s) whose emotions are handled. The main findings of the study are the five emotion-handling strategies that could be constructed from the data. The negotiation-like manner in which personnel managers handled emotions in crisis situations proved especially interesting. They were actually negotiating emotional value for their organisations. Further, they handled their own emotions within the frame of two logics of appropriateness labelled mothering and guide-following. The episodes described also enabled identification of the values enacted by the personnel managers in handling emotions. The study provides descriptive information on emotion handling, a current and relevant feature in the practice of personnel management. It seeks to offer a frame for developing practical principles that can be helpful in a crisis. It also offers the opportunity to consider a variety of difficult situations that personnel managers may confront in their work.

Being in between: An Ethnographic Study of Opera and Dialogical Identity Construction

The paradoxical co-existence of conflicting logics governs practices in cultural organizations. This requires ‘balancing acts’ between artistic and managerial efforts, which are often subjects to struggle among the organizational members. This ethnographic study aims to go beyond either-or thinking on the paradoxical organizational context by examining how the organizational members of an opera house construct views on their organization in dialogical meaning-making processes. Various professional groups, dozens of upcoming productions, increased international cooperation, and global competition combined with scarce financial resources make opera houses a complex though interesting context for organization studies. In order to provide a deeper knowledge of the internal dynamics of an opera organization this thesis takes an interpretative view to examine the ways organizational members construct and make sense of their organization. How is the opera organization constructed by the organizational members? How do the members draw on different logics when relating to their organization? Or what are the elements that characterize the relational processes of organizational identity construction in an opera organization? The thesis aims to answer these questions by providing a detailed description of the everyday life of an opera organization and a particular focus put on organizational identity construction. The processes of organizational identity construction are approached from a relational point of view. This may involve various relations between multiple positions, different professional groups, other organizations in the cultural field or between past and present understandings of an organization. The study shows that the construction of an opera organization involves not only the two conflicting logics of art and economy, but also the logic of a national institution. The study suggests also that organizational identities are constructed through processes related to the dialogics of positions, work and management practices. The dialogics involve various struggles through which the organizational members find themselves between the different organizational aspects such as visiting ‘stars’ and an ensemble or between ‘Finnishness’ of opera productions and internationalization. In addition, the study argues that a struggle between different elements is a general mode of relation in cultural organizations and therefore an inherent and enduring aspect in the organizational identity construction. However, the space of ‘being in between’ involves both the enabling and constraining elements in the dialogical identity construction in the context of cultural organizations, which present the struggle in a more generative light.

Active vibration suppression of beams with discrete actuators using optimal dynamic inversion

Most of the structural elements like beams, cables etc. are flexible and should be modeled as distributed parameter systems (DPS) to represent the reality better. For large structures, the usual approach of 'modal representation' is not an accurate representation. Moreover, for excessive vibrations (possibly due to strong wind, earthquake etc.), external power source (controller) is needed to suppress it, as the natural damping of these structures is usually small. In this paper, we propose to use a recently developed optinial dynamic inversion technique to design a set of discrete controllers for this purpose. We assume that the control force to the structure is applied through finite number of actuators, which are located at predefined locations in the spatial domain. The method used in this paper determines control forces directly from the partial differential equation (PDE) model of the system. The formulation has better practical significance, both because it leads to a closed form solution of the controller (hence avoids computational issues) as well as because a set of discrete actuators along the spatial domain can be implemented with relative ease (as compared to a continuous actuator).

Rethinking Service Companies’ Business Logic: Do We Need a Customer-Dominant Logic as a Guideline?

Purpose –This paper explores and expands the roles of customers and companies in creating value by introducing a new a customer-based approach to service. The customer’s logic is examined as being the foundation of a customer-based marketing and business logic. Design/methodology/approach – The authors argue that both goods-dominant logics and service-dominant logics are provider-dominant. Contrasting the customer-dominant logic with provider-dominant logics, the paper examines the creation of service value from the perspectives of value-in-use, the customer’s own context, and the customer’s experience of service. Findings –Moving from a provider-dominant logic to a customer-dominant logic uncovered five major challenges to service marketers: Company involvement, company control in co-creation, visibility of value creation, locus of customer experience, and character of customer experience. Research limitations/implications – The paper is exploratory. It presents and discusses a conceptual model and suggests implications for research and practice. Practical implications –Awareness of the mechanisms of customer logic will provide businesses with new perspectives on the role of the company in their customer’s lives. We propose that understanding the customer’s logic should represent the starting-point for the marketer’s business logic. Originality/value – The paper increases the understanding of how the customer’s logic underpins the customer-dominant business logic. By exploring consequences of applying a customer-dominant logic, we suggest further directions for theoretical and empirical research.