Dynamic Process (dynamic + process)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Introduction: Second Language Development as a Dynamic Process

MODERN LANGUAGE JOURNAL, Issue 2 2008
KEES 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]


Dynamic Processes at Solid-liquid Interfaces

IMAGING & MICROSCOPY (ELECTRONIC), Issue 1 2006
Video-STM Images Nanoscale Dynamics
Scanning tunnelling microscopy (STM) not only provides unsurpassed resolution, enabling real-space imaging of individual surface atoms, but also is capable to operate in a wide range of environments, ranging from ultrahigh vacuum to gases and liquids. The latter allows studies of processes at solidliquid interfaces with a time resolution that can be as low as some 10 msec. in modern instruments. This is sufficiently fast to study elementary transport processes at these interfaces, such as surface diffusion or crystal growth, directly on the atomic scale. [source]


Learning the Dynamic Processes of Color and Light in Interior Design

JOURNAL OF INTERIOR DESIGN, Issue 2 2009
Tiiu Poldma Ph.D.
ABSTRACT Interior environments and their design are profoundly influenced by how designers integrate color and light with form and space. In our increasingly global world, new lighting technologies are changing our perception of color and light and subsequently our interrelationships with one another and with interior space. This alters the choices that we have as designers when we make both color and light decisions. Traditional light and color theories are being challenged with new lighting approaches that are complex, dynamic, and that are changing people's immediate experiences within spaces. Currently, new light technologies alter our perceptual relationships with people and forms, as light, its spectral color, and the forms its affects are more interactive and modulated in real time. Usually, in interior design coursework, students learn about color and light as static theories that they are then asked to apply within the interior design of spaces in subsequent design studios. Through a presentation and examination of the course "Color and Light in Interior Design," this paper proposes considering integrating color and light theories with new contexts of dynamic, integrated human experiences of color and light in interior space. Students acquire learning experiences that integrate theory and practice by understanding the complex interrelationships of light, color, and objects in interior spaces as interactive, and by exploring design concepts in actual environments as a laboratory where they can test theories and their own ideas. The course structure is described and the theories underlying the course goals are explored. Color and light theories are considered in the context of emerging technologies and how phenomenological approaches affect our perceptions and experiences in spaces. Student examples of two of the four course projects are presented as these put theories into practice. The discussion shows that light and color theory, when explored in this way, stimulates both comprehensive and creative responses that integrate new technology with aesthetic theory and functional aspects of well-designed light/color solutions. The integrating of practice into theory stimulates reflective thinking and an understanding of situated contexts in interior design problem solving. The course develops emerging necessities of understanding dynamic color/light concepts that contribute to broadening interior design applied knowledge. [source]


Dynamic process programming for a robotic manipulator based on hopfield NN monotonous optimization searching

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 7 2004
Zhongwei Yu
A new approach to programming the optimal dynamic process for an n -joint rigid robotic manipulator with the use of the monotonous optimization searching ability of a Hopfield NN is presented. By combining robotic dynamics, this paper designs a programmed controller, which satisfies the aforementioned dynamic process. The convergence of the programmed controller is investigated. Simulations and experiments demonstrate the effectiveness of the scheme described. © 2004 Wiley Periodicals, Inc. [source]


Autonomy through identification: a qualitative study of the process of identification used by people with type 2 diabetes

JOURNAL OF CLINICAL NURSING, Issue 7b 2008
Albine Moser MPH
Aims and objectives., The aim of this study is to clarify the process of identification with diabetes as a dimension of autonomy as described by people with type 2 diabetes. Background., People with type 2 diabetes view autonomy as competency in shaping one's life. This concept of autonomy has seven dimensions, which emerged as categories in prior research. Dynamic processes shape these dimensions of autonomy. One of the dimensions of autonomy is identification. Method., This study has a qualitative descriptive and exploratory design and an inductive approach as described in grounded theory. Data were collected by means of in-depth interviews. The sample consisted of 15 people with type 2 diabetes mellitus in a nurse-led, shared-care setting in the Netherlands. Results., The phases of identification are comprehending, struggling, evaluating and mastering. Each phase has its own characteristics. Identifying with the diabetes is a non-linear, cyclical and continuous process because people with diabetes have to deal with changing conditions. Conclusion., The dynamics of identification is directed to a process of identifying with diabetes and its care requirement. Recognizing identification as an element of autonomy enables nurses to adopt a more patient-oriented view of autonomy. Relevance to clinical practice., Nursing that fosters the process of identification promotes autonomy. This implies that a person with diabetes should be able to identify with the nurse's interventions. Hence it is vital that nurses build supportive partnerships when providing care for such a patient. [source]


Dynamic processes of conceptual change: Analysis of constructing mental models of chemical equilibrium

JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 8 2002
Mei-Hung Chiu
The purpose of this study was to investigate students' mental models of chemical equilibrium using dynamic science assessments. Research in chemical education has shown that students at various levels have misconceptions about chemical equilibrium. According to Chi's theory of conceptual change, the concept of chemical equilibrium has constraint-based features (e.g., random, simultaneous, uniform activities) that might prevent students from deeply understanding the nature of the concept of chemical equilibrium. In this study, we examined how students learned and constructed their mental models of chemical equilibrium in a cognitive apprenticeship context. Thirty 10th-grade students participated in the study: 10 in a control group and 20 in a treatment group. Both groups were presented with a series of hands-on chemical experiments. The students in the treatment group were instructed based on the main features of cognitive apprenticeship (CA), such as coaching, modeling, scaffolding, articulation, reflection, and exploration. However, the students in the control group (non-CA group) learned from the tutor without explicit CA support. The results revealed that the CA group significantly outperformed the non-CA group. The students in the CA group were capable of constructing the mental models of chemical equilibrium,including dynamic, random activities of molecules and interactions between molecules in the microworld,whereas the students in the non-CA group failed to construct similar correct mental models of chemical equilibrium. The study focuses on the process of constructing mental models, on dynamic changes, and on the actions of students (such as self-monitoring/self-correction) who are learning the concept of chemical equilibrium. Also, we discuss the implications for science education. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 688,712, 2002 [source]


Assessment of gestational age and neuromaturation

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2005
Marilee C. Allen
Abstract Neuromaturation is the functional development of the central nervous system (CNS). It is by its very nature a dynamic process, a continuous interaction between the genome and first the intrauterine environment, then the extrauterine environment. Understanding neuromaturation and being able to measure it is fundamental to infant neurodevelopmental assessment. Fetal and preterm neuromaturation has become easier to observe with the advent of prenatal ultrasonography and neonatal intensive care units. A number of measures of degree of fetal maturation have been developed and used to estimate gestational age (GA) at birth. The most reliable measures of GA are prenatal measures, especially from the first trimester. Postnatal GA measurements tend to be least accurate at the extremes of gestation, that is, in extremely preterm and post-term infants. Observations of measures of neuromaturation in infants born to mothers with pregnancy complications, including intrauterine growth restriction, multiple gestation, and chronic hypertension, have led to the discovery that stressed pregnancies may accelerate fetal pulmonary and CNS maturation. This acceleration of neuromaturation does not occur before 30 weeks' gestation and has a cost with respect to cognitive limitations manifested in childhood. The ability to measure fetal and preterm neuromaturation provides an assessment of neurodevelopmental progress that can be used to reassure parents or identify at risk infants who would benefit from limited comprehensive follow-up and early intervention services. In addition, measures of neuromaturation have the potential to provide insight into mechanisms of CNS injury and recovery, much-needed early feedback in intervention or treatment trials and a measure of early CNS function for research into the relationships between CNS structure and function. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:21,33. [source]


Gene transfer by electroporation into hemogenic endothelium in the avian embryo

DEVELOPMENTAL DYNAMICS, Issue 6 2010
Catalina Ana Rosselló
Abstract Hematopoiesis is the dynamic process whereby blood cells are continuously produced in an organism. Blood cell production is sustained by a population of self-renewing multipotent hematopoietic stem cells (HSCs) throughout the life of an organism. Cells with definitive HSC properties appear in the mid-gestation embryo as dense clusters of cells budding from the floor of the aorta, and that of the vitelline and umbilical arteries in the aorta-gonads-mesonephros region. Attempts to genetically modify the aortic floor from which these HSCs arise have been unsuccessful in the mouse, since the regulation of gene expression in the hemogenic endothelium is largely unknown. Here we report the implementation of gene transfer by electroporation into dorsal aortic endothelial cells in the chick embryo. This approach provides a quick and reproducible method of generating gain/loss-of-function models to investigate the function of genes involved in HSC birth. Developmental Dynamics 239:1748,1754, 2010. © 2010 Wiley-Liss, Inc. [source]


Report of the ILAE Classification Core Group

EPILEPSIA, Issue 9 2006
Jerome Engel Jr Chair
Summary:, A Core Group of the Task Force on Classification and Terminology has evaluated the lists of epileptic seizure types and epilepsy syndromes approved by the General Assembly in Buenos Aires in 2001, and considered possible alternative systems of classification. No new classification has as yet been proposed. Because the 1981 classification of epileptic seizure types, and the 1989 classification of epilepsy syndromes and epilepsies are generally accepted and workable, they will not be discarded unless, and until, clearly better classifications have been devised, although periodic modifications to the current classifications may be suggested. At this time, however, the Core Group has focused on establishing scientifically rigorous criteria for identification of specific epileptic seizure types and specific epilepsy syndromes as unique diagnostic entities, and is considering an evidence-based approach. The short-term goal is to present a list of seizure types and syndromes to the ILAE Executive Committee for approval as testable working hypotheses, subject to verification, falsification, and revision. This report represents completion of this work. If sufficient evidence subsequently becomes available to disprove any hypothesis, the seizure type or syndrome will be reevaluated and revised or discarded, with Executive Committee approval. The recognition of specific seizure types and syndromes, as well as any change in classification of seizure types and syndromes, therefore, will continue to be an ongoing dynamic process. A major purpose of this approach is to identify research necessary to clarify remaining issues of uncertainty, and to pave the way for new classifications. [source]


Metabolic age modelling: the lesson from centenarians

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2000
G. Paolisso
Evolutionary theories of ageing, and data emerging from cellular and molecular biology of ageing, suggested that animals and humans capable of reaching an age close to the extreme limit of the life span should be equipped with a very efficient network of anti-ageing mechanisms. Indeed several evidences have demonstrated that starting from young to very old subjects, ageing is associated with a progressive remodelling. Thus, a new paradigm, the remodelling theory of age, was proposed. This theory, focusing on the human immune system, suggested that immunosenescence is the net result of the continuous adaptation of the body to the deteriorative changes occurring over time. According to this hypothesis, body resources are continuously optimized, and immunosenescence must be considered a very dynamic process including both loss and gain. Whether the metabolic pathways and the endocrine functions are also part of the age remodelling is not investigated. The aim of this review is to focus on the age-related changes in metabolic pathways and endocrine functions and to demonstrate that healthy centenarians (HC) represent the best living example of successful age-remodelling in whom the age remodelling has occurred without problems. In order to design the clinical picture of such successful ageing, anthropometric, endocrine and metabolic characteristics of healthy centenarians (HC), compared with aged subject, have been outlined. [source]


The Emergence and Institutionalisation of the European Higher Education and Research Area

EUROPEAN JOURNAL OF EDUCATION, Issue 4 2008
ERIC BEERKENS
Since the European unification project started in the 1950s, rules, regulations and policies have been formulated by the European Union (and its predecessors) to facilitate the flow of products and people; those who benefited from the increasing transnational exchange urged European actors to remove remaining obstacles and further facilitate European trade and mobility. In the field of higher education and research, this transnational activity has led to the emergence of European rules, a strengthening of European institutions and the development of a European higher education and research community. In other words, it has led to the institutionalisation of the European higher education and research area (EHERA). The argument put forward in this article is that these three dimensions and the increase in transnational activity shape a dynamic process of which further integration of the EHERA is likely to be a result. [source]


Early cytoskeletal rearrangement during dendritic cell maturation enhances synapse formation and Ca2+ signaling in CD8+ T cells

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2004
Marco Averbeck
Abstract The interplay between dendritic cells (DC) and T cells is a dynamic process critically depending on DC maturation. Ca2+ influx is one of the initial events occurring during DC/T cell contacts. To determine how DC maturation influences DC/T cell contacts, time-lapse video microscopy was established using TCR-transgenic CD8+ T cells from P14 mice. DC maturation shifted DC/T cell contacts from short-lived interactions with transient Ca2+ influx in T cells to long-lasting interactions and sustained Ca2+ influx of 30,min and more. Follow-up of DC/T cell interactions after 2,h using confocal microscopy revealed that long-lasting Ca2+ responses in T cells were preferentially associated with the formation of an immunological synapse involving CD54 and H2-Kb at the DC/T cell interface. Such synapse formation preceded MHC or B7 up-regulation, since DC developed into potent Ca2+ stimulators 7,h after initiation of maturation. Instead, the enhanced capacity of 7,h-matured DC to induce sustained Ca2+ responses in CD8+ T cells is critically dependent on the polarization and rearrangement of the cytoskeleton, as shown by Clostridium difficile toxin B inhibitor experiments. These data indicate that already very early after receiving a maturation stimulus, DC display enhanced cytoskeletal activity resulting in the rapid formation of immunological synapses and effective CD8+ T cell stimulation. [source]


Dynamic Behavior of an N -Metalated ,-Enaminoimine Complex , Preparation of N -Phosphanylenamine and ,-Enaminoimine Derivatives

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 5 2003
Alexandrine Maraval
Abstract Variable-temperature NMR spectroscopy of the ,-enaminoimine complex 2 showed a dynamic process which was attributed to an internal fluxional aldimido N -zirconated ,-linear/,-bent structure. Such an internal rearrangement has been previously proposed to occur in these systems but never observed. We have prepared a variety of (N -phosphanyl-,-enamino)imine ligands using the hydrozirconation/transmetalation reaction of malonodinitrile compounds RCH(CN)2 (R = H, PPh2). In addition to their potential uses in coordination chemistry, these systems are good tools for the study of intramolecular hydrogen bonding. The X-ray crystal structure of 14 at 180 K shows an unsymmetrical system with the N(H) proton localized on one of the two chelating nitrogen atoms, consistent with the existence in solution of a low barrier proton transfer process with a double-well potential. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


PET visualization of microglia in multiple sclerosis patients using [11C]PK11195

EUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2003
J. C. Debruyne
Activated microglia are involved in the immune response of multiple sclerosis (MS). The peripheral benzodiazepine receptor (PBR) is expressed on microglia and up-regulated after neuronal injury. [11C]PK11195 is a positron emission tomography (PET) radioligand for the PBR. The objective of the present study was to investigate [11C]PK11195 imaging in MS patients and its additional value over magnetic resonance imaging (MRI) concerning the immuno-pathophysiological process. Seven healthy and 22 MS subjects were included. Semiquantitative [11C]PK11195 uptake values were assessed with normalization on cortical grey matter. Uptake in Gadolinium-lesions was significantly increased compared with normal white matter. Uptake in T2-lesions was generally decreased, suggesting a PBR down-regulation. However, uptake values increased whenever a clinical or MR-relapse was present, suggestive for a dynamic process with a transient PBR up-regulation. During disease progression, an increase of normal-appearing white matter (NAWM) uptake was found, propagating NAWM as the possible real burden of disease. In conclusion, [11C]PK11195 and PET are able to demonstrate inflammatory processes with microglial involvement in MS. [source]


On scientists' discomfort in fisheries advisory science: the example of simulation-based fisheries management-strategy evaluations

FISH AND FISHERIES, Issue 2 2010
Sarah B M Kraak
Abstract Scientists feel discomfort when they are asked to create certainty, where none exists, for use as an alibi in policy-making. Recently, the scientific literature has drawn attention to some pitfalls of simulation-based fisheries management-strategy evaluation (MSE). For example, while estimates concerning central tendencies of distributions of simulation outcomes are usually fairly robust because they are conditioned on ample data, estimates concerning the tails of distributions (such as the probability of falling below a critical biomass) are usually conditional on few data and thus often rely on assumptions that have no strong knowledge base. The clients of scientific advice, such as the European Commission, are embracing the mechanization of the evaluation of proposed Harvest Control Rules against the precautionary principle and management objectives. Where the fisheries management institutions aim for simple answers from the scientists, giving ,green/red light' to a proposed management strategy, the scientists are forced into a split position between satisfying the demands of their advisory role and living up to the standards of scientific rigour. We argue against the mechanization of scientific advice that aims to incorporate all relevant processes into one big model algorithm that, after construction, can be run without circumspection. We rather encourage that fisheries advice should be a dynamic process of expert judgement, incorporating separate parallel concurrent, lines of scientific evidence, from quantitative and qualitative modelling exercises and factual knowledge of the biology and the fishery dynamics. This process can be formalized to a certain degree and can easily accommodate stakeholder viewpoints. [source]


Dynamical similarity of explosions at Stromboli volcano

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2004
S. De Martino
SUMMARY We analyse Strombolian explosions recorded with broadband seismometers to quantify the degree of similarity among explosions. First, we construct the trajectory space. This reconstruction is analogous to that of phase space but, unlike the phase space which relies on the analysis of a single trajectory of a dynamic system, the trajectory space takes into account many trajectories of the dynamic process to study the overlapping properties. Based on the scaling of distances between each pair of histories, it is possible to evaluate the dimension of the trajectory space. We consider the different explosions as different trajectories and, after normalizing all the records, we find that the scaling region is spread over less than one order of magnitude. This absence of scaling implies that all the trajectories cover the same attractor in the trajectory space, and that the trajectories are generated by the same dynamic system. Accordingly, we conclude that all the events are very similar to each other. This result is confirmed by the energy distribution of these events. Standard techniques of energy estimation are inadequate in this case, and we propose an evaluation method based on a quantity that is proportional to energy. The distribution function of this quantity, calculated on 580 events, displays a log-normal behaviour with very low variability (less than two orders of magnitude in energy). These results provide quantitative support for the observation that there is a great degree of similarity among Strombolian explosions and support the idea that a dynamic model underlying these events can be elaborated through the study of just one event. [source]


Intramitochondrial crystalline inclusions in nonalcoholic steatohepatitis,

HEPATOLOGY, Issue 6 2009
Stephen H. Caldwell
Mitochondrial dysfunction is an important element in the pathogenesis of nonalcoholic steatohepatitis (NASH). Intramitochondrial crystals (IMCs) are a well-documented morphological abnormality seen on transmission electron microscopy in this disease. It has been suggested that IMCs consist of phospholipids, but their exact composition remain uncertain many years after their discovery. Micellar phase transitions of phospholipid bilayers is a well-known but little-studied phenomenon in living systems. Its presence in the mitochondria of NASH would offer significant insight into the disease with possible therapeutic implications. We postulated that intramitochondrial disturbances in NASH are sufficient to produce such transitions and that their detection in fresh biopsies would therefore be a dynamic process. To test this, we performed a blinded, prospective analysis of fresh liver biopsy samples immediately fixed under different conditions. Quantitative transmission electron microscopy morphometry, performed by systematically counting total mitochondria and IMCs within areas of uniform dimension, showed a stepwise decline in IMCs with cooler fixation temperature in each subject studied. Randomization testing (Monte Carlo resampling) confirmed that the detection of IMCs was strongly dependent on fixation temperature (P < 0.0001). Conclusion: These results indicate that the intramitochondrial crystals characteristic of NASH are highly dynamic and unstable structures. The findings offer the strongest support yet for their origin in micellar phase transitions. We speculate that such transitions result from microenvironmental changes within the mitochondria and carry therapeutic implications, especially in regard to dietary manipulations of mitochondrial lipid composition. (HEPATOLOGY 2009.) [source]


Modelling the hydrologic effects of dynamic land-use change using a distributed hydrologic model and a spatial land-use allocation model

HYDROLOGICAL PROCESSES, Issue 18 2010
Hone-Jay Chu
Abstract This study develops a novel approach for modelling and examining the impacts of time,space land-use changes on hydrological components. The approach uses an empirical land-use change allocation model (CLUE-s) and a distributed hydrological model (DHSVM) to examine various land-use change scenarios in the Wu-Tu watershed in northern Taiwan. The study also uses a generalized likelihood uncertainty estimation approach to quantify the parameter uncertainty of the distributed hydrological model. The results indicate that various land-use policies,such as no change, dynamic change and simultaneous change,have different levels of impact on simulating the spatial distributions of hydrological components in the watershed study. Peak flow rates under simultaneous and dynamic land-use changes are 5·71% and 2·77%, respectively, greater than the rate under the no land-use change scenario. Using dynamic land-use changes to assess the effect of land-use changes on hydrological components is more practical and feasible than using simultaneous land-use change and no land-use change scenarios. Furthermore, land-use change is a spatial dynamic process that can lead to significant changes in the distributions of ground water and soil moisture. The spatial distributions of land-use changes influence hydrological processes, such as the ground water level of whole areas, particularly in the downstream watershed. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Navigating a Way through Plurality and Social Responsibility

INTERNATIONAL JOURNAL OF ART & DESIGN EDUCATION, Issue 1 2008
David A. GallArticle first published online: 21 JAN 200
Teachers need to have a clearer understanding of the dynamic process effecting change in culture and identity if they are to overcome fears about teaching diversity. This article draws on Eastern and Western insights on culture to clarify its dynamic process. In particular, teachers need to be aware of the two phases of culture: in one it appears as an organic integrity that suffers violence when any aspect of it is changed, removed or replaced; in the other it appears as a mechanical assemblage of parts momentarily caught in a particular relationship, comfortable with change. Each moment requires appropriate curriculum planning and pedagogical practice. Crucial to achieving that end is keeping the two phases distinct while exploring and exposing their relationship in culture and identity transformation. This will help a great deal to alleviate teachers'fears about teaching diversity or multiculturalism. [source]


Decubitus ulcers: A review of the literature

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2005
Cheryl Bansal BA
Decubitus ulcers are a worldwide health care concern affecting tens of thousands of patients and costing over a billion dollars a year. Susceptibility to pressure ulcers comes from a combination of external factors (pressure, friction, shear force, and moisture), and internal factors (e.g. fever, malnutrition, anaemia, and endothelial dysfunction). Often, enough damage is done to create the basis for a decubitus ulcer after as little as 2 h of immobility, a situation which may be difficult to avoid if the patient must undergo prolonged surgery or remain bedridden. Damage owing to pressure may also occur hours before the patient receives medical attention, especially if the patient falls or becomes immobilized owing to a vascular event. Several classification systems for decubitus ulcers have been described, based on where injury first occurs. The histologic progression of decubitus ulcers is a dynamic process involving several stages, each having characteristic histologic features. A team-focused approach integrating all aspects of care, including pressure relief, infection control, nutrition, and surgery, may improve healing rates. With accurate risk assessment and preventative care, we can hope to minimize complications and mortality owing to decubitus ulcers. [source]


The use of thrombelastography to determine coagulation status in severe anorexia nervosa: A case series

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 4 2010
Jennifer L. Gaudiani MD
Abstract Objective: Hospitalized patients with severe anorexia nervosa (AN) frequently have a complex coagulation profile, with elements of hypocoagulability-thrombocytopenia and elevated international normalized ratio (INR) and elements of hypercoagulability-usually manifested as immobility, which is either due to their marked weakness or from enforced degrees of bed rest to minimize energy expenditure. Hospitalized medical patients have been shown to have appropriate prophylaxis for venous thromboembolic (VTE) disease in only 40% of cases. Method: A simple test that could evaluate the overall coagulation profile of these patients would help guide appropriate VTE prophylaxis. The thrombelastogram is a blood test that evaluates the full dynamic process of hemostasis. Results: The study of patients did not reveal evidence of being hypocoagulable and thus should be considered for VTE prophylaxis. Discussion: We report on three cases of young women with severe AN and weakness, hospitalized for closely monitored refeeding, in whom the thromboelastogram was used to evaluate the coagulation status of the patient and assist in guiding therapy. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010 [source]


On open-set lattices and some of their applications in semantics

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 12 2003
Mouw-Ching Tjiok
In this article, we present the theory of Kripke semantics, along with the mathematical framework and applications of Kripke semantics. We take the Kripke-Sato approach to define the knowledge operator in relation to Hintikka's possible worlds model, which is an application of the semantics of intuitionistic logic and modal logic. The applications are interesting from the viewpoint of agent interactives and process interaction. We propose (i) an application of possible worlds semantics, which enables the evaluation of the truth value of a conditional sentence without explicitly defining the operator "," (implication), through clustering on the space of events (worlds) using the notion of neighborhood; and (ii) a semantical approach to treat discrete dynamic process using Kripke-Beth semantics. Starting from the topological approach, we define the measure-theoretical machinery, in particular, we adopt the methods developed in stochastic process,mainly the martingale,to our semantics; this involves some Boolean algebraic (BA) manipulations. The clustering on the space of events (worlds), using the notion of neighborhood, enables us to define an accessibility relation that is necessary for the evaluation of the conditional sentence. Our approach is by taking the neighborhood as an open set and looking at topological properties using metric space, in particular, the so-called ,-ball; then, we can perform the implication by computing Euclidean distance, whenever we introduce a certain enumerative scheme to transform the semantic objects into mathematical objects. Thus, this method provides an approach to quantify semantic notions. Combining with modal operators Ki operating on E set, it provides a more-computable way to recognize the "indistinguishability" in some applications, e.g., electronic catalogue. Because semantics used in this context is a local matter, we also propose the application of sheaf theory for passing local information to global information. By looking at Kripke interpretation as a function with values in an open-set lattice ,,U, which is formed by stepwise verification process, we obtain a topological space structure. Now, using the measure-theoretical approach by taking the Borel set and Borel function in defining measurable functions, this can be extended to treat the dynamical aspect of processes; from the stochastic process, considered as a family of random variables over a measure space (the probability space triple), we draw two strong parallels between Kripke semantics and stochastic process (mainly martingales): first, the strong affinity of Kripke-Beth path semantics and time path of the process; and second, the treatment of time as parametrization to the dynamic process using the technique of filtration, adapted process, and progressive process. The technique provides very effective manipulation of BA in the form of random variables and ,-subalgebra under the cover of measurable functions. This enables us to adopt the computational algorithms obtained for stochastic processes to path semantics. Besides, using the technique of measurable functions, we indeed obtain an intrinsic way to introduce the notion of time sequence. © 2003 Wiley Periodicals, Inc. [source]


Nonadiabatic evolution of electronic states by electron nuclear dynamics theory

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2005
Frank Hagelberg
Abstract The problem of how to determine the nonadiabatic content of any given dynamic process involving molecular motion is addressed in the context of Electron Nuclear Dynamics (END) theory. Specifically, it is proposed to cast the dynamic END wave function into the language of static electronic configurations with time dependent complex-valued amplitudes. This is achieved by adiabatic transport of an electronic basis along the classical nuclear trajectories of the studied molecular system, as yielded by END simulation. Projecting the dynamic wave function on this basis yields a natural distinction between adiabatic and nonadiabatic components of the motion considered. Tracing the evolution of the leading configurations is shown to be a helpful device for clarifying the physical nature of electronic excitation processes. For illustration of these concepts, dynamic configuration analysis is applied to the scattering of a proton by a lithium atom. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [source]


Pirouetting in chiral [2]catenanes,

ISRAEL JOURNAL OF CHEMISTRY, Issue 2 2007
Seogshin Kang
One of the best known classes of mechanically interlocked molecules is the category of [2]catenanes, which exhibit donor-acceptor interactions between the 1,5-dioxynaphthalene (DNP) units in a crown ether and the bipyridinium units in the tetracationic cyclophane, cyclobis(paraquat- p -phenylene) (CBPQT4+). In order to gain an in-depth understanding and appreciation of the stereochemistry and dynamic behavior of these [2]catenanes, chiral analogues,having both the DNP ring, which is capable of displaying planar chirality, and the axially chiral binaphthol (BINAP) moiety (as both enantiomers and as the racemic modification), in a crown ether, in addition to the CBPQT4+ cyclophane,have been synthesized using a template-directed protocol. Dynamic 1H NMR spectroscopy shows that (i) the presence of immutable axial chirality, arising from the BINAP moiety in the crown ether component, leads to no induction of diastereoselectivity,the chiral catenanes exist as a mixture of diastereoisomers in solution at low temperatures in the approximate ratio of 1:1, (ii) the barrier (,GcD,) to the interconversion between these two diastereoisomers is 7.9 ± 0.1 kcal mol,1 at 171 K, and (iii) no induction of diastereoselectivity is observed upon the addition of a chiral solvating agent to the chrial catenanes. The pattern of behavior in the variable temperature 1H NMR spectra and the low ,TGcD, value indicates that the dynamic process involving the interconversion between these two diastereoisomers is one of a pirouetting nature. Of the four possible diastereoisomers, only two, (R)-(pR/pS) or (S)-(pR/pS), are shown to exist in solution. [source]


Keeping off the grass?

JOURNAL OF APPLIED ECONOMETRICS, Issue 4 2004
An econometric model of cannabis consumption in Britain
This paper presents estimates of a dynamic individual-level model of cannabis consumption, using data from a 1998 survey of young people in Britain. The econometric model is a split-population generalization of the non-stationary Poisson process, allowing for separate dynamic process for initiation into cannabis use and subsequent consumption. The model allows for heterogeneity in consumption levels and behavioural shifts induced by leaving education and the parental home. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Cellular organization and appearance of differentiated structures in developing stages of the parasitic platyhelminth Echinococcus granulosus

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2005
Claudio Martínez
Abstract Echinococcus granulosus is the causative agent of hydatidosis, a major zoonoses that affects humans and herbivorous domestic animals. The disease is caused by the pressure exerted on viscera by hydatid cysts that are formed upon ingestion of E. granulosus eggs excreted by canine. Protoscoleces, larval forms infective to canine, develop asynchronously and clonally from the germinal layer (GL) of hydatid cysts. In this report, we describe the cellular organization and the appearance of differentiated structures both in nascent buds and developed protoscoleces attached to the GL. Early protoscolex morphogenesis is a highly complex and dynamic process starting from the constitution of a foramen in the early bud, around which nuclei are distributed mainly at the lateral and apical regions. Similarly, distribution of nuclei in mature protoscoleces is not homogenous but underlies three cellular territories: the suckers, the rostellar pad, and the body, that surrounds the foramen. Several nuclei are associated to calcareous corpuscles (Cc), differentiated structures that are absent in the earlier bud stages. The number of nuclei is similar from the grown, elongated bud stage to the mature protoscolex attached to the GL, strongly suggesting that there is no significant cellular proliferation during final protoscolex development. The amount of DNA per nucleus is in the same range to the one described for most other platyhelminthes. Our results point to a sequential series of events involving cell proliferation, spatial cell organization, and differentiation, starting in early buds at the GL of fertile hydatid cysts leading to mature protoscoleces infective to canine. © 2004 Wiley-Liss, Inc. [source]


AKT and MAPK signaling in KGF-treated and UVB-exposed human epidermal cells

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2007
Lavinia Vittoria Lotti
Regulation of proliferation and differentiation in keratinocyte is a complex and dynamic process that involves activation of multiple signaling pathways triggered by different growth factors. Keratinocyte growth factor (KGF) is not only a potent mitogen, but differently from other growth factors, is a potent inducer of differentiation. The MAP kinase and AKT pathways are involved in proliferation and differentiation of many cell types including keratinocytes. We investigated here the role of KGF in modulating AKT and MAPK activity during differentiation of human keratinocytes. Our results show that the mechanisms of action of KGF are dose-dependent and that a sustained activation of the MAPK signaling cascade causes a negative regulation of AKT. We also demostrated increasing expression of KGFR substrates, such as PAK4 during keratinocyte differentiation parallel to the receptor upregulation. J. Cell. Physiol. 212:633,642, 2007. © 2007 Wiley-Liss, Inc. [source]


An exploration of mothers' and fathers' views of their identities in chronic-kidney-disease management: parents as students?

JOURNAL OF CLINICAL NURSING, Issue 23 2008
Veronica Swallow
Aim., To explore parents' views of their identities as they learn to manage their child's chronic kidney disease. Background., Parents are expected to participate in management and usually learn necessary skills from the multidisciplinary team. Research highlights the importance of professionals defining parents' management roles in chronic disease; but little is known about parents' views on their own identities as the complex and dynamic process of teaching and learning unfolds around their child's condition. According to positioning theory, identity development is a dynamic and fluid process that occurs during interaction, with each person positioning themselves while simultaneously positioning the other person, yet this concept has not been considered in relation to parents' contributions to disease management. Design., A longitudinal, grounded theory study conducted in a UK Children's Kidney Unit. Method., This paper focuses on one aspect of a larger study exploring family learning in disease management. Six mothers and two fathers of six children with a recently diagnosed chronic kidney disease participated in a total of 21 semi-structured interviews during the 18 months after referral to the unit. Interviews included discussion about the parts they played in relation to professionals during the management process. Findings were interpreted within a framework of positioning theory. Results., Parents participated in teaching/learning/assessment that was both planned (involving allocated clinical lessons and tasks) and spontaneous (in response to current situations), to facilitate their participation. They positioned multidisciplinary team members as teachers as well as professionals, simultaneously positioning themselves as students as well as parents. Conclusion., Parents' clinical duties and obligations are not an automatic part of parenting but become part of the broader process of sharing disease management, this can lead to them assuming the additional identity of a ,student'. Relevance to clinical practice., Involving parents in ongoing discussions about their positions in management may help promote their active and informed participation. [source]


Subcutaneous pseudomembranous fat necrosis: new observations,/linkr>

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2002
Carlos Diaz-Cascajo
Background: Pseudomembranous fat necrosis is a peculiar manifestation of necrosis of adipose tissue characterized by formation of pseudocystic cavities lined by crenulated membranes. The underlying mechanism for the formation of pseudomembranes is unknown and numerous hypotheses have been proposed. Despite divergent interpretations, most authors consider necrotic fat cells to be the anatomic substrate for the formation of pseudomembranes. Methods: A total of 341 panniculitides were reviewed for the presence of pseudomembranous fat necrosis. The specific diagnoses were established after correlation of all available clinical and laboratory data with the histopathology. Special attention was given to the time in the evolution of the disease when the biopsy was taken. Additional immunohistochemical studies were performed in 12 cases. Results: Thirty of 341 cases of different types of panniculitides were found to show pseudomembranous fat necrosis, namely: 10 of 15 cases of sclerosing panniculitis (lipodermatosclerosis), 6 of 95 cases of erythema nodosum, 7 of 34 cases of traumatic panniculitis, 1 of 7 cases of lupus panniculitis, 1 of 20 cases of erythema induratum Bazin (nodular vasculitis), 1 of 9 cases of necrobiosis lipoidica, 1 of 4 cases of sclerotic lipogranuloma, 1 of 9 cases of infectious panniculitis (erysipelas), 1 of 2 cases of pancreatic panniculitis, and 1 of 4 cases of subcutaneous sarcoidosis. Pseudomembranous fat necrosis labelled strongly for the histiocytic markers CD68 and lysozyme. Conclusions: Our series provides data suggesting that pseudomembranous fat necrosis represents a dynamic process that varies according to the evolution of the lesion at the time of the biopsy. In biopsies taken from early foci of panniculitides pseudomembranes show vescicular or picnotic nuclei. Later, pseudomembranes retain their crenulated appearance but lack nuclear elements. Furthermore, we present histopathologic, histochemical, and immunohistochemical evidence that pseudomembranous fat necrosis results from the interaction of residual products of disintegrated fat cells and macrophages. Histiocytic markers such as CD68 and lysozyme may be used as reliable tools in order to detect pseudomembranes in panniculitides. [source]


Dynamic process programming for a robotic manipulator based on hopfield NN monotonous optimization searching

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 7 2004
Zhongwei Yu
A new approach to programming the optimal dynamic process for an n -joint rigid robotic manipulator with the use of the monotonous optimization searching ability of a Hopfield NN is presented. By combining robotic dynamics, this paper designs a programmed controller, which satisfies the aforementioned dynamic process. The convergence of the programmed controller is investigated. Simulations and experiments demonstrate the effectiveness of the scheme described. © 2004 Wiley Periodicals, Inc. [source]