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Systems Theory (system + theory)
Kinds of Systems Theory Selected AbstractsFunctional consistency across two behavioural modalities: fire-setting and self-harm in female special hospital patientsCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 1 2007Sarah Miller Background,Fire-setting and self-harm behaviours among women in high security special hospitals may be understood using Shye's Action System Theory (AST) in which four functional modes are recognized: ,adaptive', ,expressive', ,integrative', and ,conservative'. Aims,To test for relationships between different forms of fire-setting and self-harm behaviours and AST modes among women in special hospital, and for consistency within modes across the two behaviours. Method,Clinical case files evidencing both fire-setting and self-harm behaviours (n = 50) were analysed for content, focusing on incident characteristics. A total of 29 fire-setting and 22 self-harm variables were analysed using Smallest Space Analysis (SSA). Chi-square and Spearman's rho (,) analyses were used to determine functional consistency across behavioural modes. Results,Most women showed one predominant AST mode in fire-setting (n = 39) and self-harm (n = 35). Significant positive correlations were found between integrative and adaptive modes of functioning. The lack of correlation between conservative and expressive modes reflects the differing behaviours used in each activity. Despite this, significant cross-tabulations revealed that each woman had parallel fire-setting and self-harm styles. Discussion,Findings suggest that, for some women, setting fires and self harm fulfil a similar underlying function. Support is given to AST as a way of furthering understanding of damaging behaviours, whether self- or other-inflicted. Copyright © 2007 John Wiley & Sons, Ltd. [source] Design of Metabolic Engineering Strategies for Maximizing l -(,)-Carnitine Production by Escherichia coli.BIOTECHNOLOGY PROGRESS, Issue 2 2005Bioreactor Levels, Integration of the Metabolic In this work metabolic engineering strategies for maximizing l -(,)-carnitine production by Escherichia coli based on the Biochemical System Theory (1,3) and the Indirect Optimization Method are presented (4). The model integrates the metabolic and the bioreactor levels using power-law formalism. Based on the S-system model, the Indirect Optimization Method was applied, leading to profiles of parameter values that are compatible with both the physiology of the cells and the bioreactor system operating conditions. This guarantees their viability and fitness and yields higher rates of l -(,)-carnitine production. Experimental results using a high cell density reactor were compared with optimized predictions from the Indirect Optimization Method. When two parameters (the dilution rate and the initial crotonobetaine concentration) were directly changed in the real experimental system to the prescribed optimum values, the system showed better performance in l -(,)-carnitine production (74% increase in production rate), in close agreement with the modelapos;s predictions. The model shows control points at macroscopic (reactor operation) and microscopic (molecular) levels where conversion and productivity can be increased. In accordance with the optimized solution, the next logical step to improve the l -(,)-carnitine production rate will involve metabolic engineering of the E. coli strain by overexpressing the carnitine transferase, CaiB, activity and the protein carrier, CaiT, responsible for substrate and product transport in and out of the cell. By this means it is predicted production may be enhanced by up to three times the original value. [source] The Network Perspective: An Integration of Attachment and Family Systems Theories,FAMILY PROCESS, Issue 3 2002FRANZCP, Kasia Kozlowska MBBS In this article we discuss the network paradigm as a useful base from which to integrate attachment and family systems theories. The network perspective refers to the application of general systems theory to living systems, and provides a framework that conceptualizes the dyadic and family systems as simultaneously distinct and interconnected. Network thinking requires that the clinician holds multiple perspectives in mind, considers each system level as both a part and a whole, and shifts the focus of attention between levels as required. Key epistemological issues that have hindered the integration of the theories are discussed. These include inconsistencies within attachment theory itself and confusion surrounding the theoretical conceptualizations of the relationship between attachment and family systems theories. Detailed information about attachment categories is provided using the Dynamic Maturational model. Case vignettes illustrating work with young children and their families explore the clinical implications of integrating attachment data into family therapy practice. [source] Bowen systems theory and mediationCONFLICT RESOLUTION QUARTERLY, Issue 2 2000Wayne Regina The field of mediation is largely technique- and process-driven. In an effort to develop a more comprehensive theoretical system for mediation, this article applies Bowen Systems Theory to mediation. The article begins with a brief overview of the development of Bowen Systems Theory; it proceeds to define its central concepts, including differentiation, triangulation, and chronic anxiety; finally, the article applies these concepts to mediation and discusses the relationship between theory and technique, using caucusing and co-mediation as examples. The article concludes that Bowen Systems Theory naturally extends to mediation, providing this field with a comprehensive theoretical system. [source] The Productive Power of Ambiguity: Rethinking Homosexuality through the Virtual and Developmental Systems TheoryHYPATIA, Issue 1 2005ANN BURLEINArticle first published online: 9 JAN 200 This paper juxtaposes Deleuze's notion of the virtual alongside Oyama's notion of a developmental system in order to explore the promises and perils of thinking bodily identity as indeterminate at a time when new technologies render bodily ambiguity increasingly productive of both economic profit and power relations. [source] Do maternal stress and home environment mediate the relation between early income-to-need and 54-months attentional abilities?INFANT AND CHILD DEVELOPMENT, Issue 5 2007Janean E. Dilworth-Bart Abstract Using Ecological Systems Theory and stage sequential modelling procedures for detecting mediation, this study examined how early developmental contexts impact preschoolers' performances on a measure of sustained attention and impulse control. Data from 1273 European-American and African-American participants in the NICHD Study of Early Child Care were used to identify the potential mediators of the relation between early household income-to-need (INR) and 54-month impulsivity and inattention. Exploratory analyses were also conducted to determine whether the relationships between early income, home environment, parenting stress, and the outcome variables differ for African-American versus European-American-American children. We found modest support for the study hypothesis that 36-month home environment quality mediated the INR/attention relationship. INR accounted for more home environment score variance and home environment accounted for more Impulsivity score variance for African-American children. Home environments were related to inattention in the European-American, but not African-American, group. Copyright © 2007 John Wiley & Sons, Ltd. [source] Space, Boundaries, and the Problem of Order: A View from Systems TheoryINTERNATIONAL POLITICAL SOCIOLOGY, Issue 3 2007Jan Helmig The idea our global polity is chiefly divided by territorially organized nation-states captures contemporary constellations of power and authority only insufficiently. Through a decoupling of power and the state, political spaces no longer match geographical spaces. Instead of simply acknowledging a challenge to the state, there is the need to rethink the changing meaning of space for political processes. The paper identifies three aspects, a reconceptualization of the spatial assumptions that IR needs to address: the production of space, the constitutive role of boundaries, and the problem of order. With this contribution, we argue that one avenue in understanding the production of space and the following questions of order is by converging systems theory and critical geopolitics. While the latter has already developed a conceptual apparatus to analyze the production of space, the former comes with an encompassing theoretical background, which takes "world society" as the starting point of analysis. In this respect, nation states are understood as a form of internal differentiation of a wider system, namely world society. [source] Some Problems and Possibilities in the Study of Dynamical Social ProcessesJOURNAL FOR THE THEORY OF SOCIAL BEHAVIOUR, Issue 1 2000John E. Puddifoot The recent challenge of Dynamical Systems Theory (also known as ComplexityTheory or Chaos Theory) to the social sciences, is based largely on the beliefthat processes in the social arena can be considered as analogous to those of the natural world, and that in consequence general theoretical advances in explaining the latter might with advantage be applied to the former. This paper aims to show that claims for Dynamical Systems Theory with respect to the understanding or measurement of social processes would be premature; the reasons for this lying not only in the unfamiliarity and operational difficulties of Dynamical Systems Theory in itself, but also in the problematic nature and history of our usage of the term ,social process'. Reviewing some examples of such usage from Sociology and Social Psychology, it is concluded that Dynamical Systems Theory might serve as a catalyst for a re-examination of existing orthodoxies and major concepts, but that progress would be retarded by the uncritical application of it's terminology, concepts, and techniques of mathematical modelling, without this prior and demanding first step. [source] INITIAL LEVELS OF DIFFERENTIATION AND REDUCTION IN PSYCHOLOGICAL SYMPTOMS FOR CLIENTS IN MARRIAGE AND FAMILY THERAPYJOURNAL OF MARITAL AND FAMILY THERAPY, Issue 1 2005Suzanne Bartle-Haring Using Bowen Family Systems Theory as a theoretical underpinning, in this study, we investigated the hypothesis that clients with higher levels of differentiation would improve more quickly in therapy than clients with lower levels of differentiation. Hierarchical Linear Modeling was used to analyze the data over nine sessions of therapy in a sample from an on-campus training clinic. The results suggest that there was variation in the initial levels of psychological symptoms and that differentiation was a significant predictor of this variance. The results also suggest that although psychological symptoms decreased over the nine sessions of therapy, there was very little variance in this change. These results are discussed in relation to Bowen Theory. The difficulties of doing this type of research and the lessons learned from this project are also discussed. [source] Issues in Growing a Family Business: A Strategic Human Resource ModelJOURNAL OF SMALL BUSINESS MANAGEMENT, Issue 1 2001Sandra W. King The conceptual literature on family businesses suggests that family businesses have difficulty managing their human resources, especially when it concerns a family member or the transition from the founder to the successor. The authors empirically examined the assumptions raised in the conceptual literature regarding whether family businesses were experiencing human resource problems in growing their business and what factors enabled or constrained the ability of their businesses to grow. The authors used in-depth interviewing to collect data in order to emphasize the depth of the issue. Using content analysis with subject matter experts coding the data, the authors sought to mine the richness of data. Finally, the authors analyzed the data using Elliot Jaques' Stratified Systems Theory as a model to examine the strategic human resource issues and to draw some tentative conclusions. [source] Introduction: Second Language Development as a Dynamic ProcessMODERN LANGUAGE JOURNAL, Issue 2 2008KEES DE BOT In this contribution, some of the basic characteristics of complex adaptive systems, collectively labeled Dynamic Systems Theory (DST), are discussed. Such systems are self-organizing, dependent on initial conditions, sometimes chaotic, and they show emergent properties. The focus in DST is on development over time. Language is seen as a dynamic system, and language development, both acquisition and attrition, as a dynamic process. A number of examples of possible applications of DST in the field of applied linguistics are mentioned. After a short presentation of each of the individual articles, some possible lines of research are discussed. [source] Resolving the Anti-Antievolutionism Dilemma: A Brief for Relational Evolutionary Thinking in AnthropologyAMERICAN ANTHROPOLOGIST, Issue 2 2009Emily Schultz ABSTRACT Anthropologists often disagree about whether, or in what ways, anthropology is "evolutionary." Anthropologists defending accounts of primate or human biological development and evolution that conflict with mainstream "neo-Darwinian" thinking have sometimes been called "creationists" or have been accused of being "antiscience." As a result, many cultural anthropologists struggle with an "anti-antievolutionism" dilemma: they are more comfortable opposing the critics of evolutionary biology, broadly conceived, than they are defending mainstream evolutionary views with which they disagree. Evolutionary theory, however, comes in many forms. Relational evolutionary approaches such as Developmental Systems Theory, niche construction, and autopoiesis,natural drift augment mainstream evolutionary thinking in ways that should prove attractive to many anthropologists who wish to affirm evolution but are dissatisfied with current "neo-Darwinian" hegemony. Relational evolutionary thinking moves evolutionary discussion away from reductionism and sterile nature,nurture debates and promises to enable fresh approaches to a range of problems across the subfields of anthropology. [Keywords: evolutionary anthropology, Developmental Systems Theory, niche construction, autopoeisis, natural drift] [source] Practitioner Review: Approaches to assessment and treatment of children with DCD: an evaluative reviewTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 8 2005Peter H. Wilson Background:, Movement clumsiness (or Developmental Coordination Disorder , DCD) has gained increasing recognition as a significant condition of childhood. However, some uncertainty still exists about diagnosis. Accordingly, approaches to assessment and treatment are varied, each drawing on distinct theoretical assumptions about the aetiology of the condition and its developmental course. Method:, This review evaluates the current status of different approaches to motor assessment and treatment for children with DCD. These approaches are divided according to their broad conceptual origin (or explanatory framework): Normative Functional Skill Approach, General Abilities Approach, Neurodevelopmental Theory, Dynamical Systems Theory, and the Cognitive Neuroscientific Approach. Conclusions:, Each conceptual framework is shown to support assessment and treatment methods with varying degrees of conceptual and psychometric integrity. The normative functional skill approach supports the major screening devices for DCD and cognitive (or top-down) approaches to intervention. The general abilities approach and traditional neurodevelopmental theory are not well supported by recent research. The dynamical systems approach supports promising trends in biomechanical or kinematic analysis of movement, ecological task analysis, and task-specific intervention. Finally, and more recently, the cognitive neuroscientific approach has generated some examples of process-oriented assessment and treatment based on validated (brain,behaviour) models of motor control and learning. A multi-level approach to movement assessment and treatment is recommended for DCD, providing a more complete representation of motor development at different levels of function , behavioural, neurocognitive, and emotional. [source] A new synthesis: Resituating approaches to the evolution of human behaviourANTHROPOLOGY TODAY, Issue 3 2009Agustín Fuentes Most anthropologists would agree that humans are simultaneously historical, biological, behavioral, and social. However, many researchers retain a relatively dualistic paradigm dividing anthropological questions into biological and/or social aspects. Many practitioners of Neo-Darwinian perspectives prioritize natural selection in all explanations of human evolution. Many other anthropologists refuse to acknowledge a significant role for biological features and biological histories in human action, sensation, and engagement. Both perspectives are misplaced. Incorporating emerging perspectives in evolutionary theory into the broader anthropological discourse may help discard simplistic dualisms and resituate our assessments of the evolution of human behavior. In this essay I review three major emergent themes in evolutionary theory; Multi-Inheritance Systems Theory, Developmental Systems Theory, and Niche Construction. I suggest, with one brief example, that placing these elements in transaction with other perspectives in anthropology might enhance the possibilities of assessing human evolution and behavior. [source] THE USE OF THEORY IN FAMILY THERAPY RESEARCH: A CONTENT ANALYSIS OF FAMILY THERAPY JOURNALSJOURNAL OF MARITAL AND FAMILY THERAPY, Issue 1 2000Dale R. Hawley Ninety-five studies from Family Process and Journal of Marital and Family Therapy were evaluated with regard to their use of theory. While a majority of the articles were judged to use theory in either an explicit or an implicit manner, 42% did not appear to draw on theory in either the introductory or discussion sections. Studies that used qualitative methods appeared to use theory more frequently and explicitly than those using quantitative methods alone. Systems theory was found to be the most common conceptual framework, followed by feminism. We conclude that the link between theory and reasearch in family therapy needs strengthening and suggest that the role of theory in family therapy be reexamined. [source] A network of net-workers: report of the Euresco conference on ,Bacterial Neural Networks' held at San Feliu (Spain) from 8 to 14 May 2004MOLECULAR MICROBIOLOGY, Issue 1 2004Klaas J. Hellingwerf Summary In May 2004, over 100 bacteriologists from 19 different countries discussed recent progress in identification and understanding of individual signal transfer mechanisms in bacteria and in the mutual interactions between these systems to form a functional living cell. The meeting was held in San Feliu and supported by ESF and EMBO. In part through the extensive sequencing efforts of the past few years, the bulk of the bacterial signal transfer systems have been resolved and their detailed characterization is revealing such characteristics as signal specificity, signalling rate constants, molecular interaction affinities, subcellular localization, etc., which should provide a solid basis to a computational extension of this field of studies. In parallel, the new genomics techniques are providing tools to characterize the way a collection of such systems interact in an individual cell, to give rise to ,life'. Systems theory provides rational and convenient ways to bring order to the wide range of observables thus obtained. Ultimately, the performance of engineered design will have to prove whether or not we know enough about the processes involved. [source] Major Innovation as a Dynamic Capability: A Systems Approach,THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2008Gina Colarelli O'Connor Major innovation (MI), composed of both radical and really new innovation, is an important mechanism for enabling the growth and renewal of an enterprise. Yet it is poorly managed in most established firms, and success stories are rare. This conceptual article draws on systems theory, recent advances in dynamic capabilities theory, and the management of innovation literature to offer a framework for building an MI dynamic capability. The framework is composed of seven elements that together form a management system rather than a process-based approach to nurturing radical innovation. These system elements are (1) an identifiable organization structure; (2) interface mechanisms with the mainstream organization, some of which are tightly coupled and others of which are loose; (3) exploratory processes; (4) requisite skills and talent development, given that entrepreneurial talent is not present in most organizations; (5) governance and decision-making mechanisms at the project, MI portfolio, and MI system levels; (6) appropriate performance metrics; and (7) an appropriate culture and leadership context. It is argued that dynamic capabilities for phenomena as complex as MI must be considered in a systems fashion rather than as operating routines and repeatable processes as the literature currently suggests. A set of propositions is offered regarding how each element should play out in this parallel management system. Finally, each element's role in the major innovation system is justified in terms of four criteria required by systems theory: (1) The system is identifiable, and its elements are interdependent; (2) the effect of the whole is greater than the sum of the parts; (3) homeostasis is achieved through interaction and networking with the larger organization; and (4) there is a clear purpose in the larger system in which the MI management system is embedded. Examples are given to demonstrate these criteria. Systems theory offers a new way of thinking about dynamic capability development and management. [source] Nonlinear epigenetic variance: review and simulationsDEVELOPMENTAL SCIENCE, Issue 1 2010Kees-Jan Kan We present a review of empirical evidence that suggests that a substantial portion of phenotypic variance is due to nonlinear (epigenetic) processes during ontogenesis. The role of such processes as a source of phenotypic variance in human behaviour genetic studies is not fully appreciated. In addition to our review, we present simulation studies of nonlinear epigenetic variance using a computational model of neuronal network development. In each simulation study, time series for monozygotic and dizygotic twins were generated and analysed using conventional behaviour genetic modelling. In the results of these analyses, the nonlinear epigenetic variance was subsumed under the non-shared environmental component. As is commonly found in behaviour genetic studies, observed heritabilities and unique environmentabilities increased with time, whereas common environmentabilities decreased. The fact that the phenotypic effects of nonlinear epigenetic processes appear as unsystematic variance in conventional twin analyses complicates the identification and quantification of the ultimate genetic and environmental causes of individual differences. We believe that nonlinear dynamical system theories provide a challenging perspective on the development of individual differences, which may enrich behaviour genetic studies. [source] Creating and Justifying Research and Development Value: Scope, Scale, Skill and Social Networking of R&DCREATIVITY AND INNOVATION MANAGEMENT, Issue 1 2002Aard J. Groen In this paper we describe a framework for analysing the creation and justification of Research & Development. The 4S framework is developed for analysing the scope, scale, skills and social network aspects of Research & Development value. The framework is based on social system theory, a process contingency model, and recent Research & Development metrics. We present a first empirical assessment based on a workshop using the 4S framework for leveraging Research & Development. Results that assist in the assessment of value creation utilising R & D within networks are very relevant in high tech industries. The multi,dimensional process approach of this framework seems promising for understanding and managing R&D value creation, but needs further operationalisation. Case studies are described and a Dutch network on leveraging R&D has been initiated. [source] Signal representation and approximation,fundamental limitsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2007Holger Boche The expansion of functions in orthonormal bases is an important analytical and practical instrument in many different areas such as in signal processing, in system and information theory and in communications. However, the selection of an optimal basis is a non-trivial task in general and depends strongly on the performance measure of the concrete problem. This paper considers the basis selection problem for three different applications, starting with a problem from system theory, looking on entropy based methods from information theory, and finally it investigates the peak-to-average power ratio problem in communication systems. In particular, it is investigated under which conditions the problems are solvable, that is under which conditions there exists an appropriate basis. Copyright © 2007 John Wiley & Sons, Ltd. [source] An Optimal Grey PID Control SystemIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2009Guo-Dong Li Non-member Abstract The PID control algorithm has been widely applied in many industry control system to solve efficiently the control problems of manufacturing processes. However, PID control algorithm belong to "delay control", because it functions on basis of the actions occurred in the system. Thus the control accuracy in real-time is limited. In this paper, in order to realize the accurate control in real-time, the grey model based on grey system theory is first proposed to combine with PID control to establish the control system. We define the proposed control system as grey PID control system. Then the cubic spline function is integrated into the grey model. to enhance the control accuracy of system. To further improve the performance, the particle swarm optimization (PSO) algorithm is employed to optimize the parameters of PID algorithm. Finally, we validated the effectiveness of the proposed control system by computer simulation. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Analysis of the current methods used to size a wind/hydrogen/fuel cell-integrated system: A new perspectiveINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 12 2010H. G. Geovanni Abstract As an alternative to the production and storage of intermittent renewable energy sources, it has been suggested that one can combine several renewable energy technologies in one system, known as integrated or hybrid system, that integrate wind technology with hydrogen production unit and fuel cells. This work assesses the various methods used in sizing such systems. Most of the published papers relate the use of simulation tools such as HOMER, HYBRID2 and TRNSYS, to simulate the operation of different configurations for a given application in order to select the best economic option. But, with these methods one may not accurately determine certain characteristics of the energy resources available on a particular site, the profiles of estimated consumption and the demand for hydrogen, among other factors, which will be the optimal parameters of each subsystem. For example, velocity design, power required for the wind turbine, power required for the fuel cell and electrolyzer and the storage capacity needed for the system. Moreover, usually one makes excessive use of bi-parametric Weibull distribution function to approximate the histogram of the observed wind to the theoretical, which is not appropriate when there are bimodal frequency distributions of wind, as is the case in several places in the world. A new perspective is addressed in this paper, based on general system theory, modeling and simulation with a systematic approach and the use of exergoeconomic analysis. There are some general ideas on the advantages offered in this method, which is meant for the implementation of wind/hydrogen/fuel cell-integrated systems and in-situ clean hydrogen production. Copyright © 2009 John Wiley & Sons, Ltd. [source] Higher order explicit time integration schemes for Maxwell's equationsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5-6 2002Holger Spachmann Abstract The finite integration technique (FIT) is an efficient and universal method for solving a wide range of problems in computational electrodynamics. The conventional formulation in time-domain (FITD) has a second-order accuracy with respect to spatial and temporal discretization and is computationally equivalent with the well-known finite difference time-domain (FDTD) scheme. The dispersive character of the second-order spatial operators and temporal integration schemes limits the problem size to electrically small structures. In contrast higher-order approaches result not only in low-dispersive schemes with modified stability conditions but also higher computational costs. In this paper, a general framework of explicit Runge,Kutta and leap-frog integrators of arbitrary orders N is derived. The powerful root-locus method derived from general system theory forms the basis of the theoretical mainframe for analysing convergence, stability and dispersion characteristics of the proposed integrators. As it is clearly stated, the second- and fourth-order leap-frog scheme are highly preferable in comparison to any other higher order Runge,Kutta or leap-frog scheme concerning stability, efficiency and energy conservation. Copyright © 2002 John Wiley & Sons, Ltd. [source] Learning about dynamical systems via unfalsification of hypothesesINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 11 2004Paul B. Brugarolas Abstract This paper examines the problem of learning behaviours of a dynamical system from experimental data via unfalsification of hypotheses within the behavioural approach to system theory of Willems. Behaviours of the dynamic systems are postulated as hypotheses and then tested against experimental data. A simple and concise condition for falsification of hypotheses by experimental data in terms of a kernel is presented. The approach is applicable both to learning models for a plant and to adapting controllers to satisfy performance and robustness goals. Copyright © 2004 John Wiley & Sons, Ltd. [source] Some peculiarities of load sharing controlINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 7 2003Eduard Eitelberg In the recently published book, ,Load Sharing Control' (Eitelberg, 1999), a frequency domain, loop-by-loop load sharing control system design methodology was developed and demonstrated with engineering examples. A number of new concepts were introduced in order to characterize some peculiarities that are not relevant in single-loop control systems, or have been overlooked in the general multivariable control system theory. Some of these concepts and peculiarities are introduced and explained in this paper with a minimum of technical detail. Copyright © 2003 John Wiley & Sons, Ltd. [source] A novel mating system in a solitary carnivore: the fossaJOURNAL OF ZOOLOGY, Issue 3 2009C. E. Hawkins Abstract The mating strategies of male mammals have long been treated as broadly predictable on the basis of just two factors: the dispersion of females and the benefit of paternal care to male reproductive success. Female strategies and finer scale variations in mating systems remain poorly understood. In the fossa Cryptoprocta ferox, we had the rare opportunity to examine the mating system of a wild solitary carnivore directly, and identified features not classified or predicted by mating system theory. Males competed for mating opportunities at a traditional site monopolized by a female, high in a tree. The female mated with multiple males, repeatedly mated with some individuals and appeared to express mate choice. We observed three females thus, one replacing another on the site after each was seen to mate with four to five males over a period of 1,6 days. Copulations were prolonged (up to 3 h 8 min), involving a weak copulatory tie, and males appeared to guard females briefly after mating. Fossas are at low population density and do not use a den regularly; we suggest that both these factors impede individuals from locating a mate. We hypothesize that the observed mating system reduces this problem for both sexes, and increases the number of mates available to a female while ensuring a low risk of sexual harassment. [source] The dynamical stability of a Kuiper Belt-like regionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007A. Celletti ABSTRACT The dynamics of the Kuiper Belt region between 33 and 63 au is investigated just taking into account the gravitational influence of Neptune. Indeed the aim is to analyse the information which can be drawn from the actual exoplanetary systems, where typically physical and orbital data of just one or two planets are available. Under this perspective we start our investigation using the simplest three-body model (with Sun and Neptune as primaries), adding at a later stage the eccentricity of Neptune and the inclinations of the orbital planes to evaluate their effects on the Kuiper Belt dynamics. Afterwards we remove the assumption that the orbit of Neptune is Keplerian by adding the effect of Uranus through the Lagrange,Laplace solution or through a suitable resonant normal form. Finally, different values of the mass ratios of the primary to the host star are considered in order to perform a preliminary analysis of the behaviour of exoplanetary systems. In all cases, the stability is investigated by means of classical tools borrowed from dynamical system theory, like Poincaré mappings and Lyapunov exponents. [source] Construction of an Aboriginal Theory of Mind and Mental Health1ANTHROPOLOGY OF CONSCIOUSNESS, Issue 2 2009Lewis Mehl-Madrona ABSTRACT Most research on aboriginal mind and mental health has sought to apply or confirm preexisting European-derived theories among aboriginal people. Culture has been underappreciate. An understanding of uniquely aboriginal models for mind and mental health might lead to more effective and robust interventions. To address this issue, a core group of elders from five separate regions of North America was developed to help determine how aboriginal people conceived of mind, self, and identity before European contact. The process utilized for this study is iterative and involves discussions of teachings, traditional stories, and elder's comments on conclusions drawn. The elders endorsed a relational theory of mind in which mind exists between people as a product of the stories told and created within and by that relationship. Mind is distinguished from consciousness which is without language and exists within the individual as awareness. Language immediately results in an "out there" orientation in which two or more individuals generate stories about their experiences. The community is the basic unit of study for mind and mental health, and mental "illness" is not distinguished from physical "illness," but rather all are seen as a continuum of suffering and pain. What emerged from this research is that North American theories of mind are more closely related to Daoist and Shinto theories than to the logical positivism which drives most of North America's conventional psychology and psychiatry. Within European traditions, however, the philosophy of Mikhail Bakhtin with his emphasis on a dialogical self coupled with system theory comes closest to resembling North American aboriginal theories. This model explains why ceremony and ritual, community interventions, talking circles (including AA and the Wellbriety Movement), and family therapy are more compatible with aboriginal thought than conventional North American biomedicine and psychology. [source] Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central AfricaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 6 2009ZHANG Yamin Abstract: The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source,reservoir,seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu Gabra subsystem as a self generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu Gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10 000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect. [source] Fractal response of physiological signals to stress conditions, environmental changes, and neurodegenerative diseases,COMPLEXITY, Issue 5 2007Nicola Scafetta In the past two decades the biomedical community has witnessed several applications of nonlinear system theory to the analysis of biomedical time series and the development of nonlinear dynamic models. The development of this area of medicine can best be described as nonlinear and fractal physiology. These studies have been intended to develop more reliable methodologies for understanding how biological systems respond to peculiar altered conditions induced by internal stress, environment stress, and/or disease. Herein, we summarize the theory and some of our results showing the fractal dependency on different conditions of physiological signals such as inter-breath intervals, heart inter-beat intervals, and human stride intervals. © 2007 Wiley Periodicals, Inc. 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