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Sporotrichosis is a subcutaneous mycosis with a global distribution, also known as "rose gardener's disease". Brazil is experiencing a rapid spread of the zoonotic transmission of of Sporothrix brasiliensis, the main etiological agent of this disease in this country, affecting domestic felines. Cost-effective interventions need to be developed to control this emergent public health problem. To allow for the comparison of alternative control strategies, we propose in this paper, a mathematical model representing the transmission of S. brasiliensis among cats, stratified by age and sex. Analytical properties of the model are derived and simulations show possible strategies for reducing the endemic levels of the disease in the cat population, with a positive impact on human health. The scenarios included mass treatment of infected cats and mass implementation of contact reduction practices, such as neutering. The results indicate that mass treatment can reduce substantially the disease prevalence, and this effect is potentialized when combined with neutering or other contact-reduction interventions. On the other hand, contact-reduction methods alone are not sufficient to reduce prevalence. [ABSTRACT FROM AUTHOR]

In the context of project management, the attention given to project portfolio management has increased in recent years. The use of mathematical programming for portfolio management is also on the rise, because it integrates the project interactions with the multiple objectives of portfolio management into a single model. Among the possible objectives, recent studies have paid special attention to the emerging objective of future preparedness, which has not yet been incorporated into the existing mathematical models. This paper presents a mixed-integer nonlinear optimization model for portfolio selection that considers four main performance measures for project management, namely, value maximization, strategic alignment, balance, and future preparedness. Given the importance of the last measure, the purpose of this paper is to provide a more complete model that provides the marginal contribution and the best combination of projects according to the needs of the company. The model is tested using real data from two companies, one in Brazil and one in Canada, and the results obtained are coherent with their respective practices. [ABSTRACT FROM AUTHOR]

This paper presents an integer programming model and a matheuristic for the physician rostering problem. Constraints related to physician's preferences, legal restrictions, hospital requirements and workload balance are investigated. Moreover, a comparison of physician and nurse rostering is analyzed to identify common constraints present in both problems. The lack of a mathematical model that could be applied in the studied problem motivated the development of a new formulation. Data and constraints of the proposed physician rostering problem were provided by Hospital de Clínicas de Porto Alegre (HCPA), Brazil. Due to the difficulty of solving large instances, a matheuristic which combines integer programming and heuristic techniques was proposed to approach the problem. Computational experiments were conducted employing commercial and open-source solvers. Results revealed that open-source solvers are a good alternative to solve small problems, while the proposed matheuristic generated near-optimal results within acceptable computation time employing larger instances. [ABSTRACT FROM AUTHOR]

The presence of the golden mussel in Brazil is a matter of great concern and causes harm to the country, particularly affecting the power generation sector. Infestation control represents a challenge, and there is a need to mathematically describe the dynamics of the problem. This work proposes to analyze a mathematical model based on differential equations that relate the populations of larvae, mussels, and algae. For this model, the critical points and stationary states are determined, seeking steady-state conditions stability, through the basic reproduction rate. In addition, it presents the sensitivity analysis of the parameters involved. The paper results are relevant as they allow mathematical interpretation of the golden mussel infestation potential through the basic reproduction rate. Furthermore, the sensitivity analysis suggests how important the parameters are for this potential. For that matter, this work can provide baseline information to guide future control strategies as it provides quantification of the species involved over time as well as a condition for infestation. • Mussel-algae interaction model. • Stability analysis of stationary solutions of the model. • Basal reproduction rate for the golden mussel model. [ABSTRACT FROM AUTHOR]

This paper deals with the mathematical modeling and numerical simulations related to the coronavirus dynamics. A description is developed based on the framework of the susceptible-exposed-infectious-removed model. Initially, a model verification is carried out calibrating system parameters with data from China, Italy, Iran, and Brazil. Results show the model capability to predict infectious evolution. Afterward, numerical simulations are performed in order to analyze different scenarios of COVID-19 in Brazil. Results show the importance of the governmental and individual actions to control the number and the period of the critical situations related to the pandemic. [ABSTRACT FROM AUTHOR]

Abstract: The probability of occurrence of spread-F can be modeled and predicted using neural networks (NNs). This paper presents a feasibility study into the development of a NN based model for the prediction of the probability of occurrence of spread-F over selected equatorial stations within the Brazilian sector. The input space included the day number (seasonal variation), hour (diurnal variation), sunspot number (measure of the solar activity), magnetic index (measure of the magnetic activity) and magnetic position. Twelve years of spread-F data from Brazil (covering the period 1978–1989) measured at the equatorial site Fortaleza (3.9°S, 38.45°W) and low latitude site Cachoeira Paulista (22.6°S, 45.0°W) are used in the development of an input space and NN architecture for the model. Spread-F data that is believed to be related to plasma bubble developments (range spread-F) was used in the development of the model. The model results show the probability of spread-F occurrence as a function of local time, season and latitude. Results from the Brazilian Sector NN (BSNN) based model are presented in this paper, as well as a comparative analysis with a Brazilian model developed for the same purpose. [Copyright &y& Elsevier]

Abstract: The Amazon rainforest is one of the world''s greatest natural wonders and holds great importance and significance for the world''s environmental balance. Around 60% of the Amazon rainforest is located in the Brazilian territory. The two biggest states of the Amazon region are Amazonas (the upper Amazon) and Pará (the lower Amazon), which together account for around 73% of the Brazilian Legal Amazon, and are the only states that are serviced by international airports in Brazil''s north region. The purpose of this paper is to model and forecast sustainable international tourism demand for the states of Amazonas, Pará, and the aggregate of the two states. By sustainable tourism is meant a distinctive type of tourism that has relatively low environmental and cultural impacts. Economic progress brought about by illegal wood extraction and commercial agriculture has destroyed large areas of the Amazon rainforest. The sustainable tourism industry has the potential to contribute to the economic development of the Amazon region without destroying the rainforest. The paper presents unit root tests for monthly and annual data, estimates alternative time series models and conditional volatility models of the shocks to international tourist arrivals, and provides forecasts for 2006 and 2007. [Copyright &y& Elsevier]

• We present a new variant of the two-level lot sizing scheduling problem. • The new variant problem was inspired by a real case in the cosmetic industry. • We present a mathematical model for the proposed problem. • We also present a hybrid exact method combining different local search procedures. • We provide computational results and some managerial insights based on real data. In this paper we address a novel variant of the two-level lot-sizing and scheduling problem inspired by a cosmetic industry in Brazil. In this problem, we seek to optimize production activities in an environment consisting of two dependent levels and an intermediate inventory between them. We consider sequence-dependent setup in the first level, non-sequence dependent setup in the second level, and a different number of machines by level. Furthermore, following the mandatory requirements in the cosmetic industry, we also consider that each job must be stored for a minimum time limit and cannot exceeds a maximum time limit in the intermediate inventory. These practical requirements ensure a certain level of quality of the items produced. To solve the problem, we propose Mixed Integer Linear Programming (MILP) formulations and a hybrid exact method combining the traditional Branch and Bound (B&B) algorithm with Local Search (LS) procedures using a sequential framework. Our procedures apply several strategies of the Fix and Optimize (F&O) heuristic and Variable Neighborhood Descent (VND) principles. All methods were evaluated using a set of instances based on a real case scenario. The computational experiments indicated that our hybrid method can achieve competitive solutions, outperforming the results provided by the optimization of the MILP model. [ABSTRACT FROM AUTHOR]

This paper analyzes whether the higher the company's financial leverage, the higher the salaries demanded by staff for the embedded financial distress risk. By applying Berk, Stanton and Zechner's (2010) model, we use a 2SLS for a sample of 250 non-financial companies listed on BOVESPA from 2007 to 2009. Indeed, we find that for each additional 1% of financial leverage, the staff remunerations increase by 0.26%, controlling for Chief Executive Officer (CEO) profile. [ABSTRACT FROM AUTHOR]

Management is a practice that encompasses planning, organization, guidance, control and monitoring of activities in terms of means and ends. This paper presents a management system modelling for Distance Education in programs offered in Brazilian public institutions, using colored Petri nets. Moreover, it is important to mention that management acquires a high degree of complexity due to the fact that in order to deploy and maintain the distance learning courses, a set of processes that integrate and influence each other, aiming to reach pre-defined goals is required. Therefore, in order to achieve this level of complexity, this job involves tasks such as work division, responsibility assignments, setting levels of authority and to establish communication mechanisms. Accordingly, the systemic management system, currently applied to distance learning courses offered by IFCE (Federal Institute of Education, Science and Technology of Ceará), comprises five major pillars which are: institutional, educational, technological, administrative, financial and human resources. Hence, the scope of this work deals with the modelling of the administrative and financial management process in coloured Petri nets. The model analysis has helped to identify and improve actions and activities developed in the process. It also allowed the group to have a graphical and an administrative view, which helped them to plan and execute all the funds received to run the Distance Education courses. In addition, another important aspect to mention concerns the transformation of tacit knowledge into explicit knowledge, such that the execution of administrative and financial processes becomes less dependent on the people who devised it. [ABSTRACT FROM AUTHOR]

Abstract: Goal Programming (GP) is an important analytical approach devised to solve many realworld problems. The first GP model is known as Weighted Goal Programming (WGP). However, Multi-Choice Aspirations Level (MCAL) problems cannot be solved by current GP techniques. In this paper, we propose a Multi-Choice Mixed Integer Goal Programming model (MCMI-GP) for the aggregate production planning of a Brazilian sugar and ethanol milling company. The MC-MIGP model was based on traditional selection and process methods for the design of lots, representing the production system of sugar, alcohol, molasses and derivatives. The research covers decisions on the agricultural and cutting stages, sugarcane loading and transportation by suppliers and, especially, energy cogeneration decisions; that is, the choice of production process, including storage stages and distribution. The MCMIGP allows decision-makers to set multiple aspiration levels for their problems in which “the more/higher, the better” and “the less/lower, the better” in the aspiration levels are addressed. An application of the proposed model for real problems in a Brazilian sugar and ethanol mill was conducted; producing interesting results that are herein reported and commented upon. Also, it was made a comparison between MCMI GP and WGP models using these real cases. [Copyright &y& Elsevier]

This paper provides the main discussions of research conducted in the second half of 2009 that mapped trends and configurations of the 23 legal community radio stations active in Administrative Region of Bauru, located in Brazil's state of São Paulo. Its objective was to understand how they operate, their relation to the local population by means of to research their programming, management models strategies for sustainability, citizenship and promoting popular participation and the circumstances of the case legalization. The methodology of research adopted was the study of multiple cases combined to bibliographical research, also interviews with managers of the radio stations, study of documents and observation of their programming. [ABSTRACT FROM AUTHOR]

Our paper provides a comparative perspective on the development of public primary education in four of the largest developing economies circa 1910: Brazil, Russia, India and China (BRIC). These four countries encompassed more than 50% of the world's population in 1910, but remarkably few of their citizens attended any school by the early 20th century. We present new, comparable data on school inputs and outputs for BRIC drawn from contemporary surveys and government documents. Recent studies emphasize the importance of political decentralization, and relatively broad political voice for the early spread of public primary education in developed economies. We identify the former and the lack of the latter to be important in the context of BRIC, but we also outline how other factors such as factor endowments, colonialism, serfdom, and, especially, the characteristics of the political and economic elite help explain the low achievement levels of these four countries and the incredible amount of heterogeneity within each of them. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to comprehend social representations of kinship relations in a group consisting of twelve family firms from the pharmaceutical industry, located in the State of Minas Gerais, Brazil. In addition, the theory of social representations was employed as the methodological approach, in order to uncover representations produced by different actors about the influence of kinship relations on the family group. The results revealed the occurrence of two major representations: kinship as social integration and a mechanism for the maintenance of the established organizational order, and kinship as a source of conflict. We concluded that the family businesses all shared aspects of contradictory practices and diverse objectives; at times focusing on business objectives and needs, while at other times being dominated by personal and/or family desires. As such, it is difficult to develop formulas and analytical models to understand study objects such as the family business group. This is because its actions are characterized by simultaneous subjective and objective aspects, in a constant dynamic of interaction between family and business. [ABSTRACT FROM AUTHOR]

Abstract: A number of proposals for integrating geographical (Geographical Information Systems—GIS) and multidimensional (data warehouse—DW and online analytical processing—OLAP) processing are found in the database literature. However, most of the current approaches do not take into account the use of a GDW (geographical data warehouse) metamodel or query language to make available the simultaneous specification of multidimensional and spatial operators. To address this, this paper discusses the UML class diagram of a GDW metamodel and proposes its formal specifications. We then present a formal metamodel for a geographical data cube and propose the Geographical Multidimensional Query Language (GeoMDQL) as well. GeoMDQL is based on well-known standards such as the MultiDimensional eXpressions (MDX) language and OGC simple features specification for SQL and has been specifically defined for spatial OLAP environments based on a GDW. We also present the GeoMDQL syntax and a discussion regarding the taxonomy of GeoMDQL query types. Additionally, aspects related to the GeoMDQL architecture implementation are described, along with a case study involving the Brazilian public healthcare system in order to illustrate the proposed query language. [Copyright &y& Elsevier]

The magnitude of the basic reproduction ratio R 0 of an epidemic can be estimated in several ways, namely, from the final size of the epidemic, from the average age at first infection, or from the initial growth phase of the outbreak. In this paper, we discuss this last method for estimating R 0 for vector-borne infections. Implicit in these models is the assumption that there is an exponential phase of the outbreaks, which implies that in all cases R 0 > 1. We demonstrate that an outbreak is possible, even in cases where R 0 is less than one, provided that the vector-to-human component of R 0 is greater than one and that a certain number of infected vectors are introduced into the affected population. This theory is applied to two real epidemiological dengue situations in the southeastern part of Brazil, one where R 0 is less than one, and other one where R 0 is greater than one. In both cases, the model mirrors the real situations with reasonable accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes an optimization model to minimize the load curtailments necessary to restore the equilibrium of operating point with relaxation of restrictions. This model can be used for the operation planning of electrical power systems. The developed methodology minimizes the load cuts, limiting them to their importance and establishing different stages for them through the relaxation of the minimum limits of voltage and maximum limits of active power flows through the transformers. For instance, when an emergency occurs, if some operational limits are violated for a short period, fewer loads can be cut at a first stage than would be necessary if those violations would not be admitted. If the emergency does not cease, the remaining cuts necessary to recover the violations are made as a second stage of the strategy. On the other hand, if the contingency ceases, within this break, the system is recovered, and at this second stage, unnecessary cuts can be avoided, admitting only small breakings of operational restrictions. This methodology was tested at a system of 291 buses that is equivalent, in heavy load, to the electric network or the State of Parańa in Brazil. [ABSTRACT FROM AUTHOR]

The last decade has witnessed a steady reduction of the malaria burden worldwide. With various countries targeting disease elimination in the near future, the popular parasite infection or entomological inoculation rates are becoming less and less informative of the underlying malaria burden due to a reduced number of infected individuals or mosquitoes at the time of sampling. To overcome such problem, alternative measures based on antibodies against specific malaria antigens have gained recent interest in malaria epidemiology due to the possibility of estimating past disease exposure in absence of infected individuals. This paper aims then to review current mathematical models and corresponding statistical approaches used in antibody data analysis. The application of these models is illustrated with three data sets from Equatorial Guinea, Brazilian Amazonia region, and western Kenyan highlands. A brief discussion is also carried out on the future challenges of using these models in the context of malaria elimination. [ABSTRACT FROM AUTHOR]

Free to air television is still an important tool to provide information and communication in many countries. Therefore, the universal access to the television system is very important. This paper presents a set of Digital Television accessible remote control devices designed for the Brazilian Digital Television. A research was conducted, interviewing people with disabilities in Brazil. Three remote control models were proposed, consolidating the main identified requirements, being accessible for a diverse group of impairments. [ABSTRACT FROM PUBLISHER]

Although Brazil is predominantly a tropical country, frosts are observed with relative high frequency in the Center-Southern states of the country, affecting mainly agriculture, forestry, and human activities. Therefore, information about the frost climatology is of high importance for planning of these activities. Based on that, the aims of the present study were to develop monthly meteorological (FMET) and agronomic (FAGR) frost day models, based on minimum shelter air temperature (TMN), in order to characterize the temporal and spatial frost days variability in Center-Southern Brazil. Daily minimum air temperature data from 244 weather stations distributed across the study area were used, being 195 for developing the models and 49 for validating them. Multivariate regression models were obtained to estimate the monthly TMN, once the frost day models were based on this variable. All TMN regression models were statistically significant (p < 0.001), presenting adjusted R2 between 0.69 and 0.90. Center-Southern Brazil is mainly hit by frosts from mid-fall (April) to mid-spring (October). The period from November to March is considered as frost-free, being very rare a frost day within that period. Monthly FMET and FAGR presented significant sigmoidal relationships with TMN (p < 0.0001), with adjusted R2 above of 0.82. The residuals of the frost day models were random, which means that the sigmoidal models performed quite well for interpreting the frost day variability throughout the study area. The highlands of Santa Catarina, Rio Grande do Sul, São Paulo, and Minas Gerais had in average more than 25 and 13 frosts per year, respectively, for FMET and FAGR. The FMET and FAGR maps developed in this study for Center-Southern Brazil is a useful tool for farmers, foresters, and researchers, since they contribute to reduce frost spatial and temporal uncertainty, helping in planning project for strategic purposes. Furthermore, the monthly FMET and FAGR maps for this Brazilian region are the first zoning of these variables for the country. [ABSTRACT FROM AUTHOR]