A model of private bank-note issue

A random-matching model (ofmoney) is formulated in which there is complete public knowledge of the trading histories of a subset of the population, called the banking sector, and no public knowledge of the trading histories of the complement of that subset, called the non bank sector. Each person, whether a banker or a non banker, is assumed to have the technological capability to create indivisible and durable objects called notes. If outside money is indivisible and sufficiently scarce, then the optimal mechanism is shown to have note issue and note destruction (redemption) by members of the banking sector.

KittyCat: a cognitive model of structure-form discovery

Cognition is a core subject to understand how humans think and behave. In that sense, it is clear that Cognition is a great ally to Management, as the later deals with people and is very interested in how they behave, think, and make decisions. However, even though Cognition shows great promise as a field, there are still many topics to be explored and learned in this fairly new area. Kemp & Tenembaum (2008) tried to a model graph-structure problem in which, given a dataset, the best underlying structure and form would emerge from said dataset by using bayesian probabilistic inferences. This work is very interesting because it addresses a key cognition problem: learning. According to the authors, analogous insights and discoveries, understanding the relationships of elements and how they are organized, play a very important part in cognitive development. That is, this are very basic phenomena that allow learning. Human beings minds do not function as computer that uses bayesian probabilistic inferences. People seem to think differently. Thus, we present a cognitively inspired method, KittyCat, based on FARG computer models (like Copycat and Numbo), to solve the proposed problem of discovery the underlying structural-form of a dataset.

Labor legislation and the size of informal sector in Brazil

This paper studies the increase in the rate of informal workers in the Brazilian economy that occurred between 1985 and 1999. We develop an overlapping generations model with incomplete markets in which agents are ex-post heterogeneous. We calibrate it to match some features of the Brazilian economy for 1985. We conduct a policy experiment which reproduces the 1988 constitution reforms that increased the retirement benefits and labor costs in the formal sector. We show that these reforms can explain the increase in informal labor. Then, we conduct a policy experiment and analyze its impact on the Brazilian economy.

Duration of spermatogenesis in the bullfrog (Lithobates catesbeianus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Short-term temporal changes of soil carbon losses after tillage described by a first-order decay model

Tillage stimulates soil carbon (C) losses by increasing aeration, changing temperature and moisture conditions, and thus favoring microbial decomposition. In addition, soil aggregate disruption by tillage exposes once protected organic matter to decomposition. We propose a model to explain carbon dioxide (CO2) emission after tillage as a function of the no-till emission plus a correction due to the tillage disturbance. The model assumes that C in the readily decomposable organic matter follows a first-order reaction kinetics equation as: dC(sail)(t)/dt = -kC(soil)(t) and that soil C-CO2 emission is proportional to the C decay rate in soil, where C-soil(t) is the available labile soil C (g m(-2)) at any time (t). Emissions are modeled in terms soil C available to decomposition in the tilled and non-tilled plots, and a relationship is derived between no-till (F-NT) and tilled (F-Gamma) fluxes, which is: F-T = a1F(NT)e(-a2t), where t is time after tillage. Predicted and observed fluxes showed good agreement based on determination coefficient (R-2), index of agreement and model efficiency, with R-2 as high as 0.97. The two parameters included in the model are related to the difference between the decay constant (k factor) of tilled and no-till plots (a(2)) and also to the amount of labile carbon added to the readily decomposable soil organic matter due to tillage (a,). These two parameters were estimated in the model ranging from 1.27 and 2.60 (a(1)) and - 1.52 x 10(-2) and 2.2 x 10(-2) day(-1) (a(2)). The advantage is that temporal variability of tillage-induced emissions can be described by only one analytical function that includes the no-till emission plus an exponential term modulated by tillage and environmentally dependent parameters. (C) 2008 Elsevier B.V. All rights reserved.

Gestão de satisfação e fidelidade do cliente na hotelaria :um estudo sobre os fatores que influenciam a satisfação e a fidelidade do turista internacional no Brasil

The objective of this thesis was studying the factors which contribute to customer s satisfaction and loyalty, focusing the Norwegian model of satisfaction and loyalty of the consumer, applied in the sector of hotel services in Natal/RN, Brazil. The theoretical research was led through the concepts of service quality, customer satisfaction and loyalty, models of quality management systems, national index of customer s satisfaction and methods which evaluate the customer s satisfaction. The field research was carried through from December 1st of 2004 to 24 st, among 381 international tourists who had been housed in the hotels of Natal. The analyses of the data had been made through the descriptive statistics and analysis of multiple regression. The results had evidenced that the main precedents variables of satisfaction had been: hotel s room, staff friendliness, hotel restaurant food and price paid; these are factors which explained, in 56,0% the variation of satisfaction with hotels. In relation to the constructs which had influenced the tourist s loyalty, were founds: tourist s satisfaction, hotel image and affective commitment, which had explained 53.0% of the data variability. The complaint management resulted as a basic factor for the tourist s satisfaction and loyalty

Gestão de satisfação e fidelidade do cliente: um estudo com turistas em hotéis

This Thesis deals with a study on customer satisfaction and loyalty focusing on a model of factors antecedents of customer satisfaction and loyalty. The model is based on a Satisfaction Index model adopted in Norway developed by Johnson et al.(2001) and the service quality drivers from the literature. It is surveyed a sample of tourist in Natal. It is used a survey questionnaire applied at the airport in the departure moment of the tourist. The final sample results on 198 cases. Is is used a multiple regression analysis as the method to verify the factor affecting satisfaction and loyalty. Two models arise from the analysis. The first model concerning satisfaction results with cleaness and hygiene of the bathroom, leisure facilities, employees promptness, and price as the significant factors affecting satisfaction. The model has a R2 of 0.6430 and the also check in service, cleaness of the apartment and the hotel in general, bedroom setting have colinearity with some factors entering the model. The loyalty model results with satisfaction, affective commitment as the main factors affecting loyalty, with a R2 0.5396, and also image has collinearity with satisfaction. A small part of the sample has complained and this factor was not considered in the models. The results are consistent with the literature in term of quality as the main driver of the satisfaction and that it is not the only one factor to explain loyalty

Breeding value accuracy estimates for growth traits using random regression and multi-trait models in Nelore cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Amphetamine- and nicotine-induced cross-sensitization in adolescent rats persists until adulthood

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stress-induced reinstatement of amphetamine-conditioned place preference and changes in tyrosine hydroxylase in the nucleus accumbens in adolescent rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modeling of interfaces in two-dimensional problems using solid finite elements with high aspect ratio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Combined Pool/Bilateral Short-Term Hydrothermal Scheduling Model for Day-Ahead Energy Markets

This paper proposes a combined pool/bilateral short term hydrothermal scheduling model (PDC) for the context of the day-ahead energy markets. Some innovative aspects are introduced in the model, such as: i) the hydraulic generation is optimized through the opportunity cost function proposed; ii) there is no decoupling between physical and commercial dispatches, as is the case today in Brazil; iii) interrelationships between pool and bilateral markets are represented through a single optimization problem; iv) risk exposures related to future deficits are intrinsically mitigated; v) the model calculates spot prices in an hourly basis and the results show a coherent correlation between hydrological conditions and calculated prices. The proposed PDC model is solved by a primal-dual interior point method and is evaluated by simulations involving a test system. The results are focused on sensitivity analyses involving the parameters of the model, in such a way to emphasize its main modeling aspects. The results show that the proposed PDC provides a conceptual means for short term price formation for hydrothermal systems.

Duality of parity doublets of helicity +/- 2 in D=2+1 dimensions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On the dynamic behaviour of the "click" mechanism in dipteran flight

In this paper, the dynamic behaviour of the "click" mechanism is analysed. A more accurate model is used than in the past, in which the limits of movement due to the geometry of the flight mechanism are imposed. Moreover, the effects of different damping models are investigated. In previous work, the damping model was assumed to be of the linear viscous type for simplicity, but it is likely that the damping due to drag forces is nonlinear. Accordingly, a model of damping in which the damping force is proportional to the square of the velocity is used, and the results are compared with the simpler model of linear viscous damping. Because of the complexity of the model an analytical approach is not possible so the problem has been cast in terms of non-dimensional variables and solved numerically. The peak kinetic energy of the wing root per energy input in one cycle is chosen to study the effectiveness of the "click" mechanism compared with a linear resonant mechanism. It is shown that, the "click" mechanism has distinct advantages when it is driven below its resonant frequency. When the damping is quadratic, there are some further advantages compared to when the damping is linear and viscous, provided that the amplitude of the excitation force is large enough to avoid the erratic behaviour of the mechanism that occurs for small forces. (C) 2011 Elsevier Ltd. All rights reserved.

The early systemic and gastrointestinal oxygenation effects of hemorrhagic shock resuscitation with hypertonic saline and hypertonic saline 6% dextran-70: A comparative study in dogs

The smaller volemic state from hypertonic (7.5%) saline (HS) solution administration in hemorrhagic shock can determine lesser systemic oxygen delivery and tissue oxygenation than conventional plasma expanders. In a model of hemorrhagic shock in dogs, we studied the systemic and gastrointestinal oxygenation effects of HS and hyperoncotic (6%) dextran-70 in combination with HS (HSD) solutions in comparison with lactated Ringer's (LR) and (6%) hydroxyethyl starch (HES) solutions. Forty-eight mongrel dogs were anesthetized, mechanically ventilated, and subjected to splenectomy. A gastric air tonometer was placed. in the stomach for intramucosal gastric CO2 (Pgco(2)) determination and for the calculation of intramucosal. pH (pHi):[pHi = pHa - log(Pgco(2)/Paco(2))].The dogs were hemorrhaged (42% of blood volume) to hold mean arterial blood pressure at 40-50 mm Hg over 30 min and were then resuscitated with LR (n = 12) in a 3:1 relation to removed blood volume; HS (n = 12), 6 mL / kg; HSD (n = 12), 6 mL / kg; and HES (mean molecular weight, 200 kDa; degree of substitution, 0.5) (n = 12) in a 1:1 relation to the removed blood volume. Hemodynamic, systemic, and gastric oxygenation variables were measured at baseline, after 30 min of hemorrhage, and 5, 60, and 120 min after intravascular fluid resuscitation. After fluid resuscitation, HS showed significantly lower arterial pH and mixed venous Po-2 and higher systemic oxygen uptake index and systemic oxygenation extraction than LR and HES (P < 0.05), whereas HSD showed significantly lower arterial pH than LR and HES (P < 0.05). Only HS and HSD did not return arterial pH and pHi to control levels (P < 0.05). In conclusion, all solutions improved systemic and gastrointestinal oxygenation after hemorrhagic shock in dogs. However, the HS solution showed the worst response in comparison to LR and HES solutions in relation to systemic oxygenation, whereas HSD showed intermediate values. HS and HSD solutions did not return regional oxygenation to control values.