882 resultados para Noisy rational expectations
Resumo:
The position of the anthropologist in the field is discussed, in this article, as a position of “estranged intimacy”, that is to say, the anthropologist occupies an ambiguous position of becoming intimately involved whilst concurrently standing back. This definition derives from reflections upon fieldwork, conducted in the north of Portugal, with Cape Verdean migrant young women and their experiences as mothers. The article discusses two aspects related to the fieldwork. Firstly, the way in which diverse strategies of establishing relations in the field placed me in a position of “estranged intimacy” which reconfigured the meanings I had initially attributed to the term “Cape Verdean women”. Secondly, how becoming unexpectedly involved in a situation of intense conjugal conflict led me to reconsider my understanding of Cape Verdean gender relations. Both cases demonstrate how the endeavour to produce analytical and ethnographical knowledge was shot through with an unstable mix of detachment and involvement and how coming up against the unexpected may contribute towards the reconfiguration of ethnographic knowledge, in this specific case, with regard to the dynamics of gender relations.
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Many experiments have shown that human subjects do not necessarily behave in line with game theoretic assumptions and solution concepts. The reasons for this non-conformity are multiple. In this paper we study the argument whether a deviation from game theory is because subjects are rational, but doubt that others are rational as well, compared to the argument that subjects, in general, are boundedly rational themselves. To distinguish these two hypotheses, we study behavior in repeated 2-person and many-person Beauty-Contest-Games which are strategically different from one another. We analyze four different treatments and observe that convergence toward equilibrium is driven by learning through the information about the other player s choice and adaptation rather than self-initiated rational reasoning.
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We examine the role of expectations in the Great Moderation episode. We derive theoretical restrictions in a New-Keynesian model and test them using measures of expectations obtained from survey data, the Greenbook and bond markets. Expectations explain the dynamics of inflation and of interest rates but their importance is roughly unchanged over time. Systems with and without expectations display similar reduced form characteristics. Including or excluding expectations hardly changes the economic explanation of the Great Moderation. Results are robust to changes in the structure of the empirical model.
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I examine the impact of alternative monetary policy rules on arational asset price bubble, through the lens of an overlapping generations model with nominal rigidities. A systematic increase in interestrates in response to a growing bubble is shown to enhance the fluctuations in the latter, through its positive effect on bubble growth. Theoptimal monetary policy seeks to strike a balance between stabilization of the bubble and stabilization of aggregate demand. The paper'smain findings call into question the theoretical foundations of the casefor "leaning against the wind" monetary policies.
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Indoleamine 2,3-dioxygenase (IDO) is an important therapeutic target for the treatment of diseases such as cancer that involve pathological immune escape. We have used the evolutionary docking algorithm EADock to design new inhibitors of this enzyme. First, we investigated the modes of binding of all known IDO inhibitors. On the basis of the observed docked conformations, we developed a pharmacophore model, which was then used to devise new compounds to be tested for IDO inhibition. We also used a fragment-based approach to design and to optimize small organic molecule inhibitors. Both approaches yielded several new low-molecular weight inhibitor scaffolds, the most active being of nanomolar potency in an enzymatic assay. Cellular assays confirmed the potential biological relevance of four different scaffolds.
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We have analyzed the effects of the addition of external noise to nondynamical systems displaying intrinsic noise, and established general conditions under which stochastic resonance appears. The criterion we have found may be applied to a wide class of nondynamical systems, covering situations of different nature. Some particular examples are discussed in detail.
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This paper applies probability and decision theory in the graphical interface of an influence diagram to study the formal requirements of rationality which justify the individualization of a person found through a database search. The decision-theoretic part of the analysis studies the parameters that a rational decision maker would use to individualize the selected person. The modeling part (in the form of an influence diagram) clarifies the relationships between this decision and the ingredients that make up the database search problem, i.e., the results of the database search and the different pairs of propositions describing whether an individual is at the source of the crime stain. These analyses evaluate the desirability associated with the decision of 'individualizing' (and 'not individualizing'). They point out that this decision is a function of (i) the probability that the individual in question is, in fact, at the source of the crime stain (i.e., the state of nature), and (ii) the decision maker's preferences among the possible consequences of the decision (i.e., the decision maker's loss function). We discuss the relevance and argumentative implications of these insights with respect to recent comments in specialized literature, which suggest points of view that are opposed to the results of our study.
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We have analyzed the effects of the addition of external noise to nondynamical systems displaying intrinsic noise, and established general conditions under which stochastic resonance appears. The criterion we have found may be applied to a wide class of nondynamical systems, covering situations of different nature. Some particular examples are discussed in detail.
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BACKGROUND: In Canada, many health authorities recommend that primary care physicians (PCP) stay involved throughout their patients' cancer journey to increase continuity of care. Few studies have focused on patient and physician expectations regarding PCP involvement in cancer care. OBJECTIVE: To compare lung cancer patient, PCP and specialist expectations regarding PCP involvement in coordination of care, emotional support, information transmission and symptom relief at the different phases of cancer. DESIGN: Canadian survey of lung cancer patients, PCPs and cancer specialists PARTICIPANTS: A total of 395 patients completed questionnaires on their expectations regarding their PCP participation in several aspects of care, at different phases of their cancer. Also, 45 specialists and 232 community-based PCP involved in these patients' care responded to a mail survey on the same aspects of cancer care. RESULTS: Most specialists did not expect participation of the PCP in coordination of care in the diagnosis and treatment phases (65% and 78% respectively), in contrast with patients (83% and 85%) and PCPs (80% and 59%) (p < 0.0001). At these same phases, the best agreement among the 3 groups was around PCP role in emotional support: 84% and more of all groups had this expectation. PCP participation in symptom relief was another shared expectation, but more unanimously at the treatment phase (p = 0.85). In the advanced phase, most specialists expect a major role of PCP in all aspects of care (from 81% to 97%). Patients and PCP agree with them mainly for emotional support and information transmission. CONCLUSION: Lung cancer patient, PCP and specialist expectations regarding PCP role differ with the phase of cancer and the specific aspect of cancer care. There is a need to reach a better agreement among them and to better define PCP role, in order to achieve more collaborative and integrated cancer care.
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PURPOSE To evaluate the prevalence of acute coronary syndrome (ACS) in patients presenting initially with atypical chest pain and suspected to have pulmonary embolism (PE) or acute aortic syndromes (AAS). To evaluate the overlap between ACS, PE and AAS in routine practice and determine how many patients could have benefit from a single CT protocol to rule out ACS at the same time as PE and AAS. METHOD AND MATERIALS Our electronic hospital database revealed 1122 consecutive patients who underwent a thoracic CT angiography for PE or AAS from 2004 to 2006 (mean age, 63±13 years). Patients without chest pain were excluded from this study. Thus, 447 patients presented with isolated atypical chest were included in the analysis. All patients who underwent a thoracic CT scan previously received standard clinical care and were initially considered as non ACS. The final diagnosis was obtained by the hospital stay report. RESULTS Among the 447 patients with atypical chest pain, 25 (5.5%) were finally found to have ACS: 19 patients (4.2%) were suspected for PE and 6 (1. 3%) were suspected for AAS. There were 90 patients diagnosed to have PE, 89 (98.8%) of them were suspected for PE while only 1 (1%) was suspected for AAS. Eleven patients diagnosed to have AAS, 9 (82%) of them were suspected for AAS while 2 (18%) were suspected for PE. CONCLUSION In clinical practice, the overlap between PE, AAS and ACS is limited which make the triple rule-out studies less recommended to be done at the time being because of the high dose radiation. A double rule-out investigation is suggested to be done for patients being evaluated for atypical chest pain and suspected of having AAS or PE because of a significant overlap between the two entities as well it doesn't implicate any increment in radiation dose. CLINICAL RELEVANCE/APPLICATION With 64-slice CT, coronary circulation and total chest can be evaluated at the same time offering new opportunitie for the evaluation of three major life-threatening conditions :ACS,PE and AAS.
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Indoleamine 2,3-dioxygenase 1 (IDO1) is an important therapeutic target for the treatment of diseases such as cancer that involve pathological immune escape. Starting from the scaffold of our previously discovered IDO1 inhibitor 4-phenyl-1,2,3-triazole, we used computational structure-based methods to design more potent ligands. This approach yielded highly efficient low molecular weight inhibitors, the most active being of nanomolar potency both in an enzymatic and in a cellular assay, while showing no cellular toxicity and a high selectivity for IDO1 over tryptophan 2,3-dioxygenase (TDO). A quantitative structure-activity relationship based on the electrostatic ligand-protein interactions in the docked binding modes and on the quantum chemically derived charges of the triazole ring demonstrated a good explanatory power for the observed activities.