983 resultados para Deterministic partially self-avoiding walk


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A density-functional self-consistent calculation of the ground-state electronic density of quantum dots under an arbitrary magnetic field is performed. We consider a parabolic lateral confining potential. The addition energy, E(N+1)-E(N), where N is the number of electrons, is compared with experimental data and the different contributions to the energy are analyzed. The Hamiltonian is modeled by a density functional, which includes the exchange and correlation interactions and the local formation of Landau levels for different equilibrium spin populations. We obtain an analytical expression for the critical density under which spontaneous polarization, induced by the exchange interaction, takes place.

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Recent magnetotransport experiments of holes in InGaAs quantum dots [D. Reuter, P. Kailuweit, A. D. Wieck, U. Zeitler, O. Wibbelhoff, C. Meier, A. Lorke, and J. C. Maan, Phys. Rev. Lett. 94, 026808 (2005)] are interpreted by employing a multiband k¿p Hamiltonian, which considers the interaction between heavy hole and light hole subbands explicitly. No need of invoking an incomplete energy shell filling is required within this model. The crucial role we ascribe to the heavy hole-light hole interaction is further supported by one-band local-spin-density functional calculations, which show that Coulomb interactions do not induce any incomplete hole shell filling and therefore cannot account for the experimental magnetic field dispersion.

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The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Some Guidance on Giving Avoiding charity fraud

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The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoiding Holiday Headaches: Shopping Tips

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BACKGROUND: Little is known about coping specificities, as operationalization of the concept of affect regulation, in borderline personality disorder (BPD). It is most important to take into account methodological criticisms addressed to the self-report questionnaire approach and to compare BPD coping specificities to the ones of neighbouring diagnostic categories, such as bipolar disorder (BD). SAMPLING AND METHODS: The present exploratory study compared the coping profiles of N = 25 patients presenting BPD to those of N = 25 patients presenting BD and to those of N = 25 healthy controls. All participants underwent a clinical interview that was transcribed and rated using the Coping Patterns observer-rater system. RESULTS: Results partially confirmed study hypotheses and showed differences between BPD patients and healthy controls in all coping domains (competence, resources and autonomy), whereas the only coping domain presenting a BPD-specific lack of skills, compared with the BD patients, was autonomy, a set of coping strategies facing stress appraised as challenge. These coping processes were linked to general and BPD symptomatology. CONCLUSIONS: These results extend conclusions of earlier studies on affect regulation processes in BPD and bear important clinical implications, in the context of dialectical behavior therapy and other therapeutic approaches. Limitations of this exploratory study, such as the small sample size, are acknowledged. Copyright © 2012 John Wiley & Sons, Ltd. KEY PRACTITIONER MESSAGE: Coping can be reliably assessed in the narrative process in an non-structured interview frame. Patients with borderline personality disorder present with a specific lack of skills in affect regulation related to autonomy issues, compared to patients with bipolar disorder and healthy controls. Lack of skills in accommodation to distressing emotions in borderline personality disorder is related to symptom gravity and may be treated using radical acceptance strategies.

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Purpose This study aimed to identify self-perception variables which may predict return to work (RTW) in orthopedic trauma patients 2 years after rehabilitation. Methods A prospective cohort investigated 1,207 orthopedic trauma inpatients, hospitalised in rehabilitation, clinics at admission, discharge, and 2 years after discharge. Information on potential predictors was obtained from self administered questionnaires. Multiple logistic regression models were applied. Results In the final model, a higher likelihood of RTW was predicted by: better general health and lower pain at admission; health and pain improvements during hospitalisation; lower impact of event (IES-R) avoidance behaviour score; higher IES-R hyperarousal score, higher SF-36 mental score and low perceived severity of the injury. Conclusion RTW is not only predicted by perceived health, pain and severity of the accident at the beginning of a rehabilitation program, but also by the changes in pain and health perceptions observed during hospitalisation.

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We propose a novel mechanism leading to spatiotemporal oscillations in extended systems that does not rely on local bulk instabilities. Instead, oscillations arise from the interaction of two subsystems of different spatial dimensionality. Specifically, we show that coupling a passive diffusive bulk of dimension d with an excitable membrane of dimension d-1 produces a self-sustained oscillatory behavior. An analytical explanation of the phenomenon is provided for d=1. Moreover, in-phase and antiphase synchronization of oscillations are found numerically in one and two dimensions. This novel dynamic instability could be used by biological systems such as cells, where the dynamics on the cellular membrane is necessarily different from that of the cytoplasmic bulk.

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We have investigated hysteresis and the return-point memory (RPM) property in deterministic cellular automata with avalanche dynamics. The RPM property reflects a partial ordering of metastable states, preserved by the dynamics. Recently, Sethna et al. [Phys. Rev. Lett. 70, 3347 (1993)] proved this behavior for a homogeneously driven system with static disorder. This Letter shows that the partial ordering and the RPM can be displayed as well by systems driven heterogeneously, as a result of its own evolution dynamics. In particular, we prove the RPM property for a deterministic 2D sandpile automaton driven at a central site.

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Starting Jan. 30, 2012, the Iowa Department of Transportation (DOT) will implement new federal regulations that require all CDL holders and applicants to certify the type of driving they do, and require interstate CDL holders that carry a Medical Examiner’s Certificate to give the Iowa DOT a copy of their certificate, produced by the Iowa Department of Transportation.

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Iowa’s Family Development and Self-Sufficiency (FaDSS) Grant Program was created by the 1988 Iowa General Assembly to assist Family Investment Program (FIP) families with significant or multiple barriers reach self-sufficiency. FaDSS provides services that promote, empower, and nurture families toward economic and emotional self-sufficiency.

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Introduction: Human experience takes place in the line of mental-time (MT) created through imagination of oneself in different time-points in past or future (self-projection in time). Here we manipulated self-projection in MT not only with respect to one's life-events but also with respect to one's faces from different past and future time-points. Methods: We here compared MTT with respect to one's facial images from different time points in past and future (study 1: MT-faces) as well as with respect to different past and future life events (study 2: MT-events). Participants were asked to make judgments about past and future face images and past and future events from three different time-points: the present (Now), eight years earlier (Past) or eight years later (Future). In addition, as a control task participants were asked to make recognition judgments with respect to faces and memory-related judgments with respect to events without changing their habitual self-location in time. Behavioral measures and functional magnetic resonance imaging (fMRI) activity after subtraction of recognition and memory related activities show both absolute MT and relative MT effects for faces and events, signifying a fundamental brain mechanism of MT, disentangled from episodic memory functions. Results: Behavioural and event-related fMRI activity showed three independent effects characterized by (1) similarity between past recollection and future imagination, (2) facilitation of judgments related to the future as compared to the past, and (3) facilitation of judgments related to time-points distant from the present. These effects were found with respect to faces and events suggesting that the brain mechanisms of MT are independent of whether actual life episodes have to be re-/pre-experienced and recruited a common cerebral network including the medial-temporal, precuneus, inferior-frontal, temporo-parietal, and insular cortices. Conclusions: These behavioural and neural data suggest that self-projection in time is a crucial aspect of MT, relying on neural structures encoding memory, mental imagery, and self. Furthermore our results emphasize the idea that mental temporal processing is more strongly directed to future prediction than to past recollection.