Cisplatin is a chemotherapeutic agent that causes severe renal dysfunction. The kinin B1 receptor... more Cisplatin is a chemotherapeutic agent that causes severe renal dysfunction. The kinin B1 receptor has been associated with the migration of immune cells to injured tissue as well as with renal inflammation. To examine the role of the kinin B1 receptor in cisplatin-induced acute kidney injury, we used kinin B1 receptor knockout mice and treatment with a receptor antagonist before and after cisplatin administration. Cisplatin injection caused exacerbation of renal macrophage and neutrophil migration, higher levels of serum creatinine and blood urea, upregulation of B1 receptor mRNA and an increase in proinflammatory cytokines expression. B1 receptor knockout mice exhibited a reduction in serum creatinine and blood urea levels, diminished apoptosis, and decreased cisplatin-induced upregulation of inflammatory components. Moreover, treatment with the B1 receptor antagonist prior to cisplatin administration normalized serum creatinine, blood urea levels, protected from acute tubular necrosis, apoptosis-related genes, and prevented upregulation of pro-inflammatory cytokines. Thus, we propose that kinins have an important role in cisplatin-induced acute kidney injury by impairing immune cells migration to renal tissue during cisplatin nephrotoxicity.
As the size of adipocytes increases during obesity, the establishment of resident immune cells in... more As the size of adipocytes increases during obesity, the establishment of resident immune cells in adipose tissue becomes an important source of proinflammatory mediators. Exercise and caloric restriction are two important, nonpharmacological tools against body mass increase. To date, their effects on the immune cells of adipose tissue in obese organisms, specifically when a high-fat diet is consumed, have been poorly investigated. Thus, after consuming a high-fat diet, mice were submitted to chronic swimming training or a 30% caloric restriction in order to investigate the effects of both interventions on resident immune cells in adipose tissue. These strategies were able to reduce body mass and resulted in changes in the number of resident immune cells in the adipose tissue and levels of cytokines/chemokines in serum. While exercise increased the number of NK cells in adipose tissue and serum levels of IL-6 and RANTES, caloric restriction increased the CD4+/CD8+ cell ratio and MCP-1 levels. Together, these data demonstrated that exercise and caloric restriction modulate resident immune cells in adipose tissues differently in spite of an equivalent body weight reduction. Additionally, the results also reinforce the idea that a combination of both strategies is better than either individually for combating obesity.
The aim of the present study was to characterize single nucleotide polymorphisms (SNPs) in the pr... more The aim of the present study was to characterize single nucleotide polymorphisms (SNPs) in the promoter region of the bovine paraoxonase 1 (PON1) gene and determine their relationship with PON1 serum activity. Blood samples were collected from 47 Holstein cows during the periparturient period. Serum PON1 was measured and DNA extracted for PCR and sequencing of the promoter region of the PON1 gene. Seven novel SNPs were identified and of these, five SNPs, at positions -105, -221, -392, -611 and -674, upstream of the start of the published mRNA sequence (NM_001046269.2), were found to be associated with variability in serum PON1 activity (P < 0.05). The SNPs at positions -221 and -611 were located in regions predicted to bind to transcription factors linked to the acute phase response.
This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants... more This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants with a two-stage procedure. In the first stage, the plants' relative technical efficiency is estimated with DEA (data envelopment analysis) to establish which plants perform most efficiently. These plants could serve as peers to help improve performance of the least efficient plants. The paper ranks these plants according to their relative efficiency for the period 1996-2004. In a second stage, the Simar and Wilson [Simar, L., Wilson, P.W., 2007. Estimation and inference in two-stage, semi-parametric models of production processes. Journal of Econometrics 136, 1-34] bootstrapped procedure is adopted to estimate the efficiency drivers. Economic implications arising from the study are considered.
This article analyzes the dismissal of head coaches in the top tier of German professional footba... more This article analyzes the dismissal of head coaches in the top tier of German professional football, the ''Bundesliga". A random parameter logit model is used to analyse the characteristics that are associated with the probability of a coach to be dismissed, taking into account uncontrolled heterogeneity of the data. Policy implications are presented.
This study analyses and compares the cost efficiency of Japanese steam power generation companies... more This study analyses and compares the cost efficiency of Japanese steam power generation companies using the fixed and random Bayesian frontier models. We show that it is essential to account for heterogeneity in modelling the performance of energy companies. Results from the model estimation also indicate that restricting CO 2 emissions can lead to a decrease in total cost. The study finally discusses the efficiency variations between the energy companies under analysis, and elaborates on the managerial and policy implications of the results.
This paper uses data envelopment analysis (DEA) to evaluate the operational performance of a samp... more This paper uses data envelopment analysis (DEA) to evaluate the operational performance of a sample of AEA-Association of European Airlines from 2000 to 2005, combining operational and financial variables. In this paper an innovative DEA two-stage procedure proposed by Estimation and inference in two stage, semi-parametric models of productive efficiency. Journal of Econometrics 136, 31-64] is used. In the first stage a DEA model is used to rank the airlines by their overall efficiency. In the second stage a bootstrapped truncated regression is used to evaluate the drivers of efficiency. The regressions test the roles played, respectively, by population and network alliance in the efficiency of the airlines. The implications of this research for managerial purposes are then drawn.
This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants... more This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants with a two-stage procedure. In the first stage, the plants' relative technical efficiency is estimated with DEA (data envelopment analysis) to establish which plants perform most efficiently. These plants could serve as peers to help improve performance of the least efficient plants. The paper ranks these plants according to their relative efficiency for the period 1996-2004. In a second stage, the Simar and Wilson [Simar, L., Wilson, P.W., 2007. Estimation and inference in two-stage, semi-parametric models of production processes. Journal of Econometrics 136, 1-34] bootstrapped procedure is adopted to estimate the efficiency drivers. Economic implications arising from the study are considered.
This paper employs the two-stage procedure of to analyse the effects of deregulation on the effic... more This paper employs the two-stage procedure of to analyse the effects of deregulation on the efficiency of the Greek insurance industry. The efficiency is estimated by means of data envelopment analysis (DEA). The companies are ranked according to their CRS efficiency score for the period 1994-2003. The first stage results indicate a decline in efficiency over the sample period, while the second stage results confirm that the competition for market shares is a major driver of efficiency in the Greek insurance industry.
Laboratory investigation; a journal of technical methods and pathology, 2012
The kallikrein-kinin system (KKS) has been previously linked to glucose homeostasis. In isolated ... more The kallikrein-kinin system (KKS) has been previously linked to glucose homeostasis. In isolated muscle or fat cells, acute bradykinin (BK) stimulation was shown to improve insulin action and increase glucose uptake by promoting glucose transporter 4 translocation to plasma membrane. However, the role for BK in the pathophysiology of obesity and type 2 diabetes remains largely unknown. To address this, we generated genetically obese mice (ob/ob) lacking the BK B2 receptor (obB2KO). Despite similar body weight or fat accumulation, obB2KO mice showed increased fasting glycemia (162.3 ± 28.2 mg/dl vs 85.3 ± 13.3 mg/dl), hyperinsulinemia (7.71 ± 1.75 ng/ml vs 4.09 ± 0.51 ng/ml) and impaired glucose tolerance when compared with ob/ob control mice (obWT), indicating insulin resistance and impaired glucose homeostasis. This was corroborated by increased glucose production in response to a pyruvate challenge. Increased gluconeogenesis was accompanied by increased hepatic mRNA expression of ...
In this article, the innovative twostage procedure of Simar and Wilson (2007) is used to estimate... more In this article, the innovative twostage procedure of Simar and Wilson (2007) is used to estimate the efficiency determinants of Portuguese hotel groups from 1998 to 2005. In the first stage, the hotels’ technical efficiency is estimated with Data Envelopment Analysis (DEA), in order to establish which hotels have the most efficient performance. These could serve as peers to help
Background: Leptin-deficient mice (Lep ob /Lep ob , also known as ob/ob) are of great importance ... more Background: Leptin-deficient mice (Lep ob /Lep ob , also known as ob/ob) are of great importance for studies of obesity, diabetes and other correlated pathologies. Thus, generation of animals carrying the Lep ob gene mutation as well as additional genomic modifications has been used to associate genes with metabolic diseases. However, the infertility of Lep ob /Lep ob mice impairs this kind of breeding experiment. Objective: To propose a new method for production of Lep ob /Lep ob animals and Lep ob /Lep ob -derived animal models by restoring the fertility of Lep ob /Lep ob mice in a stable way through white adipose tissue transplantations. Methods: For this purpose, 1 g of peri-gonadal adipose tissue from lean donors was used in subcutaneous transplantations of Lep ob /Lep ob animals and a crossing strategy was established to generate Lep ob /Lep ob -derived mice. Results: The presented method reduced by four times the number of animals used to generate double transgenic models (from about 20 to 5 animals per double mutant produced) and minimized the number of genotyping steps (from 3 to 1 genotyping step, reducing the number of Lep gene genotyping assays from 83 to 6). Conclusion: The application of the adipose transplantation technique drastically improves both the production of Lep ob /Lep ob animals and the generation of Lep ob /Lep ob -derived animal models.
Page 1. Bootstrapped Technical Efficiency of African Seaports Carlos Pestana Barros, Albert Assaf... more Page 1. Bootstrapped Technical Efficiency of African Seaports Carlos Pestana Barros, Albert Assaf, and Ade Ibiwoye Abstract This paper analyzes the efficiency of a representative sample of African seaports using a bootstrapped DEA Data Envelopment Analysis approach. ...
In this paper, we assess and compare the performance of French tourism destinations, using the Da... more In this paper, we assess and compare the performance of French tourism destinations, using the Data Envelopment Analysis (DEA) two-stage procedure, where in the first stage the efficiency score are calculated, and then followed in the second stage by a bootstrapped truncated regression model. In the context of France such analysis takes an additional importance, especially as the country is
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 24, 2014
We compared the prognostic value of liver biopsy (LB) and FIB-4 index in patients with human imm... more We compared the prognostic value of liver biopsy (LB) and FIB-4 index in patients with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. We studied patients from the Grupo de Estudio del SIDA 3603 study cohort, in whom fibrosis was evaluated at baseline using both LB (Metavir score) and FIB-4 index. We assessed overall death (OD) and liver-related events (LREs), defined as decompensation or hepatocellular carcinoma, whichever occurred first. We used receiver operating characteristic (ROC) curves to determine the ability of LB and FIB-4 to predict outcomes. We also assessed the association between advanced fibrosis-LB (F3 or greater) or FIB-4 (≥3.25)-and outcomes using multivariate Cox regression analysis. The study sample comprised 903 patients (328 with sustained virologic response [SVR]). Baseline fibrosis by LB was as follows: F0, n = 71; F1, n = 242; F2, n = 236; F3, n = 236; F4, n = 118. Fibrosis by FIB-4 was as follows: ≤1, n = 148; >1 to <3.25, ...
This paper compares the efficiency of cooperatives and private enterprises in the Portuguese wine... more This paper compares the efficiency of cooperatives and private enterprises in the Portuguese wine industry, employing data envelopment analysis (DEA). The use of DEA for the analysis of comparative efficiency within a sector is a key tool in evaluating organizational competitiveness. Competitiveness should be based on benchmarking the different types of organizations that comprise the viniculture sector. We conclude that Portuguese wine cooperatives, on average, are more efficient than their private counterparts. Economic implications arising from the study are discussed.
This article introduces the Data Envelopment Analysis (DEA) bootstrap procedure to analyze the te... more This article introduces the Data Envelopment Analysis (DEA) bootstrap procedure to analyze the technical efficiency of Brazilian first league football clubs. For comparison purpose the study also estimates the efficiency scores with the traditional DEA model. From the results, it is clear that there is a significant difference between the efficiency scores derived from the traditional DEA and the bootstrap
... sample of Portuguese travel agencies. They adopted which permits an observed DMU to reach the... more ... sample of Portuguese travel agencies. They adopted which permits an observed DMU to reach the pro-a model that generates efficiency scores econome-duction frontier. ... In more economic terms, this function makes it but with a linear homogeneity cost function and a ...
This paper analyses the cost efficiency of Angola-Luanda hotels using a Bayesian stochastic front... more This paper analyses the cost efficiency of Angola-Luanda hotels using a Bayesian stochastic frontier model. The results confirm that Luanda hotels have increased their cost efficiency over the period of study to reach an overall average of 67.11%. Results from the returns to scale also indicate that further improvements in efficiency are possible if Luanda hotels would increase the size
This article uses Data Envelopment Analysis (DEA) to evaluate the performance of Portuguese pensi... more This article uses Data Envelopment Analysis (DEA) to evaluate the performance of Portuguese pension funds management companies from 1994 to 2003, combining operational and financial variables. We evaluate how close the pension funds management companies are to the best practices frontier, also analyzing how they manage their funds. Implications of this research for managerial purposes are then drawn.
Cisplatin is a chemotherapeutic agent that causes severe renal dysfunction. The kinin B1 receptor... more Cisplatin is a chemotherapeutic agent that causes severe renal dysfunction. The kinin B1 receptor has been associated with the migration of immune cells to injured tissue as well as with renal inflammation. To examine the role of the kinin B1 receptor in cisplatin-induced acute kidney injury, we used kinin B1 receptor knockout mice and treatment with a receptor antagonist before and after cisplatin administration. Cisplatin injection caused exacerbation of renal macrophage and neutrophil migration, higher levels of serum creatinine and blood urea, upregulation of B1 receptor mRNA and an increase in proinflammatory cytokines expression. B1 receptor knockout mice exhibited a reduction in serum creatinine and blood urea levels, diminished apoptosis, and decreased cisplatin-induced upregulation of inflammatory components. Moreover, treatment with the B1 receptor antagonist prior to cisplatin administration normalized serum creatinine, blood urea levels, protected from acute tubular necrosis, apoptosis-related genes, and prevented upregulation of pro-inflammatory cytokines. Thus, we propose that kinins have an important role in cisplatin-induced acute kidney injury by impairing immune cells migration to renal tissue during cisplatin nephrotoxicity.
As the size of adipocytes increases during obesity, the establishment of resident immune cells in... more As the size of adipocytes increases during obesity, the establishment of resident immune cells in adipose tissue becomes an important source of proinflammatory mediators. Exercise and caloric restriction are two important, nonpharmacological tools against body mass increase. To date, their effects on the immune cells of adipose tissue in obese organisms, specifically when a high-fat diet is consumed, have been poorly investigated. Thus, after consuming a high-fat diet, mice were submitted to chronic swimming training or a 30% caloric restriction in order to investigate the effects of both interventions on resident immune cells in adipose tissue. These strategies were able to reduce body mass and resulted in changes in the number of resident immune cells in the adipose tissue and levels of cytokines/chemokines in serum. While exercise increased the number of NK cells in adipose tissue and serum levels of IL-6 and RANTES, caloric restriction increased the CD4+/CD8+ cell ratio and MCP-1 levels. Together, these data demonstrated that exercise and caloric restriction modulate resident immune cells in adipose tissues differently in spite of an equivalent body weight reduction. Additionally, the results also reinforce the idea that a combination of both strategies is better than either individually for combating obesity.
The aim of the present study was to characterize single nucleotide polymorphisms (SNPs) in the pr... more The aim of the present study was to characterize single nucleotide polymorphisms (SNPs) in the promoter region of the bovine paraoxonase 1 (PON1) gene and determine their relationship with PON1 serum activity. Blood samples were collected from 47 Holstein cows during the periparturient period. Serum PON1 was measured and DNA extracted for PCR and sequencing of the promoter region of the PON1 gene. Seven novel SNPs were identified and of these, five SNPs, at positions -105, -221, -392, -611 and -674, upstream of the start of the published mRNA sequence (NM_001046269.2), were found to be associated with variability in serum PON1 activity (P < 0.05). The SNPs at positions -221 and -611 were located in regions predicted to bind to transcription factors linked to the acute phase response.
This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants... more This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants with a two-stage procedure. In the first stage, the plants' relative technical efficiency is estimated with DEA (data envelopment analysis) to establish which plants perform most efficiently. These plants could serve as peers to help improve performance of the least efficient plants. The paper ranks these plants according to their relative efficiency for the period 1996-2004. In a second stage, the Simar and Wilson [Simar, L., Wilson, P.W., 2007. Estimation and inference in two-stage, semi-parametric models of production processes. Journal of Econometrics 136, 1-34] bootstrapped procedure is adopted to estimate the efficiency drivers. Economic implications arising from the study are considered.
This article analyzes the dismissal of head coaches in the top tier of German professional footba... more This article analyzes the dismissal of head coaches in the top tier of German professional football, the ''Bundesliga". A random parameter logit model is used to analyse the characteristics that are associated with the probability of a coach to be dismissed, taking into account uncontrolled heterogeneity of the data. Policy implications are presented.
This study analyses and compares the cost efficiency of Japanese steam power generation companies... more This study analyses and compares the cost efficiency of Japanese steam power generation companies using the fixed and random Bayesian frontier models. We show that it is essential to account for heterogeneity in modelling the performance of energy companies. Results from the model estimation also indicate that restricting CO 2 emissions can lead to a decrease in total cost. The study finally discusses the efficiency variations between the energy companies under analysis, and elaborates on the managerial and policy implications of the results.
This paper uses data envelopment analysis (DEA) to evaluate the operational performance of a samp... more This paper uses data envelopment analysis (DEA) to evaluate the operational performance of a sample of AEA-Association of European Airlines from 2000 to 2005, combining operational and financial variables. In this paper an innovative DEA two-stage procedure proposed by Estimation and inference in two stage, semi-parametric models of productive efficiency. Journal of Econometrics 136, 31-64] is used. In the first stage a DEA model is used to rank the airlines by their overall efficiency. In the second stage a bootstrapped truncated regression is used to evaluate the drivers of efficiency. The regressions test the roles played, respectively, by population and network alliance in the efficiency of the airlines. The implications of this research for managerial purposes are then drawn.
This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants... more This paper analyses the technical efficiency of Portuguese thermoelectric power generating plants with a two-stage procedure. In the first stage, the plants' relative technical efficiency is estimated with DEA (data envelopment analysis) to establish which plants perform most efficiently. These plants could serve as peers to help improve performance of the least efficient plants. The paper ranks these plants according to their relative efficiency for the period 1996-2004. In a second stage, the Simar and Wilson [Simar, L., Wilson, P.W., 2007. Estimation and inference in two-stage, semi-parametric models of production processes. Journal of Econometrics 136, 1-34] bootstrapped procedure is adopted to estimate the efficiency drivers. Economic implications arising from the study are considered.
This paper employs the two-stage procedure of to analyse the effects of deregulation on the effic... more This paper employs the two-stage procedure of to analyse the effects of deregulation on the efficiency of the Greek insurance industry. The efficiency is estimated by means of data envelopment analysis (DEA). The companies are ranked according to their CRS efficiency score for the period 1994-2003. The first stage results indicate a decline in efficiency over the sample period, while the second stage results confirm that the competition for market shares is a major driver of efficiency in the Greek insurance industry.
Laboratory investigation; a journal of technical methods and pathology, 2012
The kallikrein-kinin system (KKS) has been previously linked to glucose homeostasis. In isolated ... more The kallikrein-kinin system (KKS) has been previously linked to glucose homeostasis. In isolated muscle or fat cells, acute bradykinin (BK) stimulation was shown to improve insulin action and increase glucose uptake by promoting glucose transporter 4 translocation to plasma membrane. However, the role for BK in the pathophysiology of obesity and type 2 diabetes remains largely unknown. To address this, we generated genetically obese mice (ob/ob) lacking the BK B2 receptor (obB2KO). Despite similar body weight or fat accumulation, obB2KO mice showed increased fasting glycemia (162.3 ± 28.2 mg/dl vs 85.3 ± 13.3 mg/dl), hyperinsulinemia (7.71 ± 1.75 ng/ml vs 4.09 ± 0.51 ng/ml) and impaired glucose tolerance when compared with ob/ob control mice (obWT), indicating insulin resistance and impaired glucose homeostasis. This was corroborated by increased glucose production in response to a pyruvate challenge. Increased gluconeogenesis was accompanied by increased hepatic mRNA expression of ...
In this article, the innovative twostage procedure of Simar and Wilson (2007) is used to estimate... more In this article, the innovative twostage procedure of Simar and Wilson (2007) is used to estimate the efficiency determinants of Portuguese hotel groups from 1998 to 2005. In the first stage, the hotels’ technical efficiency is estimated with Data Envelopment Analysis (DEA), in order to establish which hotels have the most efficient performance. These could serve as peers to help
Background: Leptin-deficient mice (Lep ob /Lep ob , also known as ob/ob) are of great importance ... more Background: Leptin-deficient mice (Lep ob /Lep ob , also known as ob/ob) are of great importance for studies of obesity, diabetes and other correlated pathologies. Thus, generation of animals carrying the Lep ob gene mutation as well as additional genomic modifications has been used to associate genes with metabolic diseases. However, the infertility of Lep ob /Lep ob mice impairs this kind of breeding experiment. Objective: To propose a new method for production of Lep ob /Lep ob animals and Lep ob /Lep ob -derived animal models by restoring the fertility of Lep ob /Lep ob mice in a stable way through white adipose tissue transplantations. Methods: For this purpose, 1 g of peri-gonadal adipose tissue from lean donors was used in subcutaneous transplantations of Lep ob /Lep ob animals and a crossing strategy was established to generate Lep ob /Lep ob -derived mice. Results: The presented method reduced by four times the number of animals used to generate double transgenic models (from about 20 to 5 animals per double mutant produced) and minimized the number of genotyping steps (from 3 to 1 genotyping step, reducing the number of Lep gene genotyping assays from 83 to 6). Conclusion: The application of the adipose transplantation technique drastically improves both the production of Lep ob /Lep ob animals and the generation of Lep ob /Lep ob -derived animal models.
Page 1. Bootstrapped Technical Efficiency of African Seaports Carlos Pestana Barros, Albert Assaf... more Page 1. Bootstrapped Technical Efficiency of African Seaports Carlos Pestana Barros, Albert Assaf, and Ade Ibiwoye Abstract This paper analyzes the efficiency of a representative sample of African seaports using a bootstrapped DEA Data Envelopment Analysis approach. ...
In this paper, we assess and compare the performance of French tourism destinations, using the Da... more In this paper, we assess and compare the performance of French tourism destinations, using the Data Envelopment Analysis (DEA) two-stage procedure, where in the first stage the efficiency score are calculated, and then followed in the second stage by a bootstrapped truncated regression model. In the context of France such analysis takes an additional importance, especially as the country is
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 24, 2014
We compared the prognostic value of liver biopsy (LB) and FIB-4 index in patients with human imm... more We compared the prognostic value of liver biopsy (LB) and FIB-4 index in patients with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. We studied patients from the Grupo de Estudio del SIDA 3603 study cohort, in whom fibrosis was evaluated at baseline using both LB (Metavir score) and FIB-4 index. We assessed overall death (OD) and liver-related events (LREs), defined as decompensation or hepatocellular carcinoma, whichever occurred first. We used receiver operating characteristic (ROC) curves to determine the ability of LB and FIB-4 to predict outcomes. We also assessed the association between advanced fibrosis-LB (F3 or greater) or FIB-4 (≥3.25)-and outcomes using multivariate Cox regression analysis. The study sample comprised 903 patients (328 with sustained virologic response [SVR]). Baseline fibrosis by LB was as follows: F0, n = 71; F1, n = 242; F2, n = 236; F3, n = 236; F4, n = 118. Fibrosis by FIB-4 was as follows: ≤1, n = 148; >1 to <3.25, ...
This paper compares the efficiency of cooperatives and private enterprises in the Portuguese wine... more This paper compares the efficiency of cooperatives and private enterprises in the Portuguese wine industry, employing data envelopment analysis (DEA). The use of DEA for the analysis of comparative efficiency within a sector is a key tool in evaluating organizational competitiveness. Competitiveness should be based on benchmarking the different types of organizations that comprise the viniculture sector. We conclude that Portuguese wine cooperatives, on average, are more efficient than their private counterparts. Economic implications arising from the study are discussed.
This article introduces the Data Envelopment Analysis (DEA) bootstrap procedure to analyze the te... more This article introduces the Data Envelopment Analysis (DEA) bootstrap procedure to analyze the technical efficiency of Brazilian first league football clubs. For comparison purpose the study also estimates the efficiency scores with the traditional DEA model. From the results, it is clear that there is a significant difference between the efficiency scores derived from the traditional DEA and the bootstrap
... sample of Portuguese travel agencies. They adopted which permits an observed DMU to reach the... more ... sample of Portuguese travel agencies. They adopted which permits an observed DMU to reach the pro-a model that generates efficiency scores econome-duction frontier. ... In more economic terms, this function makes it but with a linear homogeneity cost function and a ...
This paper analyses the cost efficiency of Angola-Luanda hotels using a Bayesian stochastic front... more This paper analyses the cost efficiency of Angola-Luanda hotels using a Bayesian stochastic frontier model. The results confirm that Luanda hotels have increased their cost efficiency over the period of study to reach an overall average of 67.11%. Results from the returns to scale also indicate that further improvements in efficiency are possible if Luanda hotels would increase the size
This article uses Data Envelopment Analysis (DEA) to evaluate the performance of Portuguese pensi... more This article uses Data Envelopment Analysis (DEA) to evaluate the performance of Portuguese pension funds management companies from 1994 to 2003, combining operational and financial variables. We evaluate how close the pension funds management companies are to the best practices frontier, also analyzing how they manage their funds. Implications of this research for managerial purposes are then drawn.
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Papers by Carlos Barros