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Avaliação bioeconômica de estratégias de alimentação em sistemas de produção de leite. 2. Metodologia alternativa: nível de utilização de capital; Bioeconomic evaluation of feeding strategies in milk production systems. 2. Alternative methodology: level of capital utilization

RENNÓ, Francisco Palma; PEREIRA, José Carlos; LEITE, Carlos Antonio Moreira; RODRIGUES, Marcelo Teixeira; CAMPOS, Oriel Fajardo de; FONSECA, Dilermando Miranda da; RENNÓ, Luciana Navajas
Fonte: Viçosa Publicador: Viçosa
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
16.84%
Objetivou-se desenvolver uma metodologia alternativa para avaliação bioeconômica de estratégias de alimentação para rebanhos leiteiros e avaliar a produtividade física e a eficiência bioeconômica de sistemas de alimentação para vacas em lactação quando utilizadas diversas estratégias de alimentação à base de volumosos para vacas de cinco níveis de produção de leite. Utilizou-se uma plataforma computacional desenvolvida com os programas CNCPS v.5.0 e planilhas eletrônicas do Microsoft Excell®, de forma a simular a produção e as exigências de nutrientes ao longo da lactação de uma vaca com cinco níveis de produção de leite. Utilizaram-se a metodologia alternativa "Ajuste para o Nível de Capital", foram observados diversos níveis de utilização de concentrados e capital gasto com alimentação por unidade de área e estimadas equações de regressão da produtividade (PROD/ha) e receita menos os custos com alimentação (LUCR/ha) por hectare, em função destes níveis. Esta metodologia não permitiu que ocorresse utilização de diferentes níveis de insumos e de capital por unidade de área, mesmo quando são avaliadas diferentes estratégias de alimentação. Os resultados obtidos comprovaram diferenças nas avaliações bioeconômicas realizadas pela metodologia "Ajuste para o Nível de Capital" em relação à "Tradicional". De modo geral...

Otimização dinâmica e controle na extração de recursos florestais; Dynamic optimization and control for forest timber harvesting

Pimentel, Carlos Eduardo Hirth
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/09/2014 PT
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Este trabalho aborda um método de otimização dinâmica baseado em modelos bioeconômicos estabelecidos na teoria do controle ótimo, que visa modelar o resultado econômico-financeiro relacionado à atividade de extração dos recursos naturais, de modo que a otimização do resultado financeiro seja controlada por uma extração sustentável desse recurso. Mais especificamente, consideramos a exploração de madeira florestal restrita a uma série de vínculos econômicos e operacionais, bem como à dinâmica de crescimento natural da floresta. Avaliando o uso efetivo dessa metodologia aplicada ao planejamento das concessões florestais e procurando contribuir com o debate a respeito da viabilidade da forma de gestão florestal baseada em concessões florestais no Brasil.; This work addresses a dynamic optimization method based on bioeconomics models established in optimal control theory, which aims to model the economic-financial result related to the activity of extraction of natural resources, so that the optimization of the financial result is controlled by a sustainable extraction of this resources. More specifically, we consider the exploration of forest wood restricted to a series of economic and operational linkages, as well as the dynamics of natural forest growth. Assessing the effective use of this methodology applied to the planning of forest concessions and seeking to contribute to the debate about the viability of forest management form based on forest concessions in Brazil.

A tragédia dos comuns revisitada : a pesca do bacalhau na Terra Nova: consequências do regime das 200 milhas

Coelho, Manuel
Fonte: Instituto Superior de Economia e Gestão Publicador: Instituto Superior de Economia e Gestão
Tipo: Tese de Doutorado
Publicado em //1999 POR
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16.84%
A investigação desenvolvida nesta dissertação centra-se no binómio Direitos de Propriedade / Política de Pescas. A transição de um regime de livre acesso para políticas de limitação à entrada e atribuição de quotas (mais ou menos transferíveis) significou uma alteração sensível na forma de entender os problemas das pescarias e de as ordenar de forma eficiente.A criação do regime das 200 milhas, ao atribuir aos países costeiros, direitos de propriedade e novas prerrogativas na gestão dos seus recursos, representou um imenso potencial para uma gestão sustentável das pescas, uma "Promessa de Abundância". A prática demonstrou que, sem uma política de redução da sobrecapacidade, e em presença de restrições de ordem social e política , estas conclusões devem ser relativizadas. Por outro lado, os problemas derivados da imprecisa definição de direitos nas zonas de Alto-Mar adjacentes às ZEEs, na Lei do Mar ( 1982), nomeadamente os relativos aos straddling stocks, implicam uma revisitação da "Tragédia dos Comums" e da relação entre regras de acesso e sobrepesca. Isto podemos comprovar pela análise do caso: A pesca do bacalhau na Terra Nova. Simultaniamente, avaliamos os efeitos da criação do regime das 200 milhas sobre a frota de pesca longínqua portuguesa que...

Evolution by co-operation. A study in bioeconomics

Doncaster, L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1914 EN
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16.84%

Humanistic and economic aspects of haemophilia treatment in Bulgaria. Comparison between two therapeutic approaches: prophylactic vs. on-demand treatment

Petrova, Guenka; Tachkov, Konstantin; Georgieva, Svetla; Dimitrova, Maria
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.84%
The aim of the present study was to calculate the cost-effectiveness of on-demand and prophylactic treatments of severe haemophilia A for Bulgarian patients. The point of view is that of all patients suffering from severe haemophilia A. An epidemiological model was created, which includes data regarding the number of patients divided into age groups up to 74 years. In the model, the transition age from prophylactic to on-demand treatment was gradually increased to up to 40 years. Costs of blood clotting factor, hospitalization, major surgery and indirect costs were considered; incremental cost-effectiveness ratio was calculated. The results showed that despite the increase in the costs for factor VIII with 20 million BGN, the saving obtained from other health services and indirect expenses reduce the overall expenses with 5.3 million BGN. If there is a gradual increase in the age when patients are transferred from a prophylactic to an on-demand regimen, the costs for factor VIII would increase from 10.4 million to 19.7 million BGN, but due to a decrease in indirect costs as well as other health service costs, the total costs would decrease. The sensitivity analysis showed that the costs for clotting factor VIII are what influences the cost-effectiveness in both regimes. This indicates that decreases in the factor VIII cost will increase the overall efficiency in both regimes. In conclusion...

Marketing approaches for OTC analgesics in Bulgaria

Petkova, Valentina; Valchanova, Velislava; Ibrahim, Adel; Nikolova, Irina; Benbasat, Niko; Dimitrov, Milen
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
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16.84%
The marketing management includes analysis of market opportunities, selection of target markets, planning, developing and implementing of marketing strategies, monitoring and result control. The object of the present study was to analyse the marketing approaches applied for non-steroidal anti-inflammatory drugs (NSAIDs) in Bulgaria. The performed SWOT(planning method used to evaluate the strengths, weaknesses, opportunities, and threats) analysis for one of the leading Bulgarian manufacturers marked the complex corporative strategy for stimulating the sales of NSAIDs. The study results show that the legislation frame in the country gives an opportunity for regulation of the NSAID market in order that incorrect marketing approaches such as disloyal competition are avoided.

Economic consequences of the vaccination against hepatitis A in the Bulgarian healthcare setting

Dimitrova, Maria; Petrova, Guenka; Tachkov, Konstantin; Bozhkova, Maria Krasteva; Kamusheva, Maria; Mitov, Konstantin
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
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16.84%
The purpose of the present analysis is to calculate and compare the costs and results of the implication of the inactivated vaccine against hepatitis A virus (HAV) in the Bulgarian healthcare setting in the period of 2002–2012. A combined pharmacoeconomic and epidemiological study was performed on the basis of the prevalence of hepatitis A infection in this 10-year period. The investments in the vaccination were considered as costs and the avoided costs in the case of vaccination of all one-year old children in the population – as benefits. The results show that the vaccination of one-year-old children would be cost effective to the healthcare system in the years with an epidemiologic outbreak, as in these years the total cost of treatment of patients with hepatitis A infection exceeds the cost for vaccination of the whole one-year-old cohort. The critical threshold is 4600 infected patients per year that equalize the benefits to costs. The inclusion of HAV vaccine in the National Immunization Calendar would be cost effective for the healthcare system when the vaccination is performed in certain risk groups and could help to decrease the circulation of the virus in the general population.

Health technology assessment in the Balkans: opportunities for a balanced drug assessment system

Dankó, Dávid; Petrova, Guenka
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.84%
Countries in the Balkan region use pharmaco-economic data for decisions about the inclusion of new pharmaceuticals into their positive drug lists, but no predefined frameworks are used and resources for health technology assessment (HTA) are limited. The goal of this analysis is to investigate into possible development directions for the HTA system in the region, and provide some practical recommendations for a sustainable model. For this purpose, the main factors currently influencing HTA in Balkan countries are briefly presented, and possible development strategies are compared. A resource-saving balanced assessment approach is proposed. It is aligned with available resources and capabilities, and helps access to new pharmaceuticals while ensuring the transparency of decision-making processes and the stability of the pharmaceutical budget.

ISO 9001 certification for hospitals in Bulgaria: does it help service?

Stoimenova, Assena; Stoilova, Ani; Petrova, Guenka
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.84%
The aim of our study is to review the published literature on establishment and implementation of ISO 9001 QMS in European hospitals, to study the availability of International Organization for Standardization (ISO) quality management systems (QMS) in Bulgarian hospitals and to outline the main advantages of ISO implementation in the hospitals in Bulgaria. The information on availability of ISO QMS in the hospitals in Bulgaria was gathered via Bulgarian certification register, the registries of various quality associations, websites of hospitals and certification companies presented in Bulgaria. A total number of 312 hospitals in Bulgaria were screened for the availability of QMS certified against the ISO 9001 requirements. The experience of European hospitals that implemented QMS is positive and the used approaches to improve the processes and the demonstrated effects from ISO implementation are analysed by the researchers. Unlike other European Union member states, the establishment of quality management systems in Bulgaria is not compulsory. However, our study revealed that 14.42% of the hospitals in Bulgaria have implemented and have certified quality systems against the requirements of ISO 9001. Our study confirmed that a quality management system using the ISO 9001 standard is useful for the hospitals as it can help to increase the operational efficiencies...

Comparison of health-related quality-of-life measurement instruments in diabetic patients

Yordanova, Stanislava; Petkova, Valentina; Petrova, Guenka; Dimitrov, Milen; Naseva, Emilia; Dimitrova, Maria; Petkova, Elina
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
EN
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16.84%
The objective of the study was to compare three different questionnaires (Short Form (SF)-6D, EuroQuol (EQ)-5D and WHO-5) to establish which one is more sensitive and which one gives an adequate assessment of the quality of life in patients with diabetes.

“Mentor in Bioeconomics avant la lettre”: A tribute to Bernard Witholt by those who worked with him

Prieto, Auxiliadora; Eggink, Gerrit; Wubbolts, Marcel
Fonte: John Wiley & Sons, Ltd Publicador: John Wiley & Sons, Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.84%

Bioeconomics of the Alfalfa Snout Beetle (Coleoptera: Curculionidae)

Bechinskp, E. J.; Hescock, R.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
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Microplot and small-plot field studies were conducted during 1988 to quantify relationships between density of alfalfa snout beetle, Otiorhynchus ligustici (L.), and alfalfa yield and quality. Cumulative dry matter yield of single plants declined as a linear function of absolute larval density at the end of the growing season. Plant stands tolerated pest presence without yield loss unless density exceeded 12.9 beetles/m2 or 150.7 beetle-days/m2. Thereafter, alfalfa yield declined as a quadratic function of beetle density but offsetting increases in stand weediness maintained total forage production (weeds + alfalfa) at constant levels. Alfalfa nutritional quality and economic value were unaffected by pest damage. Within season stand losses were 19.7 to 22.4% in plots with 20 and 25 beetles/m2. Stand winter kill was significantly greater at low to moderate pest densities compared with severe densities. A general formula was derived to compute economic injury levels (EILs) for crops characterized by tolerant responses to injury. EILs expressed as absolute pest density and pest days ranged from 15.2 to 21.6 beetles/m2 and 194 to 227 beetle-days/m2, respectively, depending on assumptions about management costs, forage market value...

Análisis de competitividad de las empresas de acuicultura. Aplicaciones empíricas al cultivo de la dorada (Sparus Aurata)y la lubina (Dicentrarchus Labrax)

Llorente García, Ignacio
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Tese de Doutorado
SPA
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RESUMEN: El presente trabajo aborda la competitividad de las empresas acuícolas desde la perspectiva de la gestión de operaciones con el objetivo de contribuir a la mejora de la eficiencia de los procesos de cultivo. Tras identificar los principales factores que determinan la competitividad de los procesos acuícolas a través de una revisión de literatura, se desarrollan tres aplicaciones empíricas independientes. La primera propone un modelo explicativo de la rentabilidad de las empresas de cultivo de dorada (Sparus aurata) y lubina (Dicentrarchus labrax) en España. La segunda aborda la optimización económica del cultivo de dorada a través de la determinación de las estrategias de producción que maximicen los beneficios presentes. La tercera tiene por objetivo analizar la posible existencia de ventajas competitivas en el cultivo de dorada en el mar Mediterráneo derivadas de las condiciones medioambientales. En las dos últimas aplicaciones se utiliza un modelo bioeconómico de engorde de dorada para la simulación del proceso de cultivo, y un algoritmo de enjambre de partículas para la optimización de las estrategias.; ABSTRACT: This study addresses the competitiveness of aquaculture companies from the perspective of operations management in order to improve the efficiency of cultivation processes. After identify the main factors that determine the competitiveness of farming processes through a review of scientific literature...

Extended Inclusive Fitness Theory bridges Economics and Biology through a common understanding of Social Synergy

Jaffe, Klaus
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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Inclusive Fitness Theory (IFT) was proposed half a century ago by W.D. Hamilton to explain the emergence and maintenance of cooperation between individuals that allows the existence of society. Contemporary evolutionary ecology identified several factors that increase inclusive fitness, in addition to kin-selection, such as assortation or homophily, and social synergies triggered by cooperation. Here we propose an Extend Inclusive Fitness Theory (EIFT) that includes in the fitness calculation all direct and indirect benefits an agent obtains by its own actions, and through interactions with kin and with genetically unrelated individuals. This formulation focuses on the sustainable cost/benefit threshold ratio of cooperation and on the probability of agents sharing mutually compatible memes or genes. This broader description of the nature of social dynamics allows to compare the evolution of cooperation among kin and non-kin, intra- and inter-specific cooperation, co-evolution, the emergence of symbioses, of social synergies, and the emergence of division of labor. EIFT promotes interdisciplinary cross fertilization of ideas by allowing to describe the role for division of labor in the emergence of social synergies, providing an integrated framework for the study of both...

Viable harvest of monotone bioeconomic models

De Lara, Michel; Gajardo, Pedro; Cabrera, Hector Ramirez
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/06/2009
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16.84%
Some monospecies age class models, as well as specific multi-species models (with so-called technical interactions), exhibit useful monotonicity properties. This paper deals with discrete time monotone bioeconomics dynamics in the presence of state and control constraints. In practice, these latter "acceptable configurations" represent production and preservation requirements to be satisfied for all time, and they also possess monotonicity properties. A state $\state$ is said to belong to the viability kernel if there exists a trajectory, of states and controls, starting from $\state$ and satisfying the constraints. Under monotonicity assumptions, we present upper and lower estimates of the viability kernel. This helps delineating domains where a viable management is possible. Numerical examples, in the context of fisheries management, for the Chilean sea bass (\emph{Dissostichus eleginoides}) and Alfonsino (\emph{Beryx splendens}) are given.

How to model marine reserves ?

Loisel, Patrice; Cartigny, Pierre
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 23/02/2013
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The safeguarding of resources is one of the principal subjects of halieutics studies. Among the solutions proposed to avert the disappearance of species, the setting in place of no take reserves is often mentioned. Most work on this subject, theoretical as well as applied, was undertaken in recent years. In this paper, we seek to compare two different models presented in existing literature by highlighting their underlying assumptions. Both models were derived from what is often referred to as the "model of Schaefer-Clark" (reference to the work of the last author on Mathematical Bioeconomics : Clark [7]). We show that various variations of this model lead to properties that can be very different.

Effort dynamics in a fisheries bioeconomic model: A vessel level approach through Game Theory; Dinámica de esfuerzo en un modelo bioeconómico pesquero: aproximación a nivel de barco a través de teoría de juegos

Merino, Gorka; Maynou, Francesc; García-Olivares, Antonio
Fonte: CSIC - Instituto de Ciencias del Mar (ICM) Publicador: CSIC - Instituto de Ciencias del Mar (ICM)
Tipo: Artículo Formato: 1928902 bytes; application/pdf
ENG
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14 pages, 8 figures, 4 tables.; [EN] Red shrimp, Aristeus antennatus (Risso, 1816) is one of the most important resources for the bottom-trawl fleets in the northwestern Mediterranean, in terms of both landings and economic value. A simple bioeconomic model introducing Game Theory for the prediction of effort dynamics at vessel level is proposed. The game is performed by the twelve vessels exploiting red shrimp in Blanes. Within the game, two solutions are performed: non-cooperation and cooperation. The first is proposed as a realistic method for the prediction of individual effort strategies and the second is used to illustrate the potential profitability of the analysed fishery. The effort strategy for each vessel is the number of fishing days per year and their objective is profit maximisation, individual profits for the non-cooperative solution and total profits for the cooperative one. In the present analysis, strategic conflicts arise from the differences between vessels in technical efficiency (catchability coefficient) and economic efficiency (defined here). The ten-year and 1000-iteration stochastic simulations performed for the two effort solutions show that the best strategy from both an economic and a conservationist perspective is homogeneous effort cooperation. However...

Optimal economic planning and control for the management of ecosystems

Macksamie, Kevin
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
17.53%
In recent years the interest on sustainable systems has increased significantly. Among the many interested problems, creating and restoring sustainable ecosystems is a challenging and complex problem. One of the fundamental problems within this area is the imbalance between species that have a predator-prey relationship. Solutions involving management have become an integral player in many environments. Management systems typically use ad hoc methods to develop harvesting policies to control the populations of species to desired numbers. In order to amalgamate intelligence and structure, ecological systems require a diverse research effort from three primary fields: ecology, economics, and control theory. In this thesis, all three primary fields aforementioned are researched to develop a theoretical framework that includes an optimal trajectory planning system that exploits an ecosystem to maximize profits for the supporting community, and a robust control system design to track the optimal trajectories subjected to exogenous disturbances. Population ecology is used to select a model that identifies the key characteristics a management system needs to understand the behavior of the natural environment. A bioeconomic model is developed to relate the species populations to revenue. The nonlinear ecosystem is transformed into a linear parameter-varying (LPV) system that is then controlled using hinf synthesis and the gain scheduling methodology. The consequences of the results in this thesis are that optimal trajectories of an ecosystem can be obtained by constructing and solving a nonlinear programming problem (NLP)...

The Bioeconomics of Marine Reserves: A Selected Review with Policy Implications

Grafton, R Quentin; Kompas, Thomas; Schneider, Viktoria
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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The paper 'bridges the divide' between the biological and economic literature on marine reserves. It provides a selected review of the traditional use of reserves, the early reserve literature, the potential benefits of reserves, spillovers from reserves

Theoretical assessment of the impact of seeding on the exploitation of some economically viable marine populations

Lacayo,Ramón; Sfeir,Rodrigo
Fonte: ASOCIACIÓN INTERCIENCIA Publicador: ASOCIACIÓN INTERCIENCIA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
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Many rural communities in the developing world practice small-scale harvesting of marine species of various kinds (fish, crustaceans, mollusks) as their main economic activity. Lack of regulation or enforcement or both has led in many cases to overexploitation of resources and consequent decline of the populations of organisms on which the communities depend. This situation, common along the north-central Chilean coast, served as the starting point of the present work. Recent advances in biotechnology and aquaculture, however, have made plausible halting or even reversing the trend towards resource depletion, favorably affecting the economic wellbeing of the communities. In this paper the theoretical implications of seeding the habitual harvesting grounds of a hypothetical community with individuals produced in the laboratory is explored. In particular, we examine the effect of periodic seeding of hatchlings or juveniles on the population of an economically important species harvested under either one of two modes of extraction, constant harvest or harvest proportional to the stock level. The population dynamics is modeled by a first order ordinary differential equation containing a series of delta functions, and which in words reads as follows: the population growth rate is equal to the natural growth rate minus the harvest rate plus the seeding rate. It was found that...