Evaluating debt repurchases: what are the alternative to investment?

In this paper a general model of debt repurchases is built which reconciles most of the points raised in the literature on debt buybacks. It is shown that results previously found in the literature can be obtained from this general model and are strongly dependant on assumptions made on its parameters. The condition that determines whether or not buybacks are an attractive solution from the point of the debtor nations is derived. Additionally it is shown that if there are other assets safer than investment, a debt buyback will always lead to an increase in investment and a reduction in the holdings of such other assets. This result holds independently of the source of the resources used for the buyback, unlike previous suggestions. With a buyback out of current resources, optimal reserves levels fall by more than what is used for the buyback, releasing extra resources for investment purposes, while current consumption does not fall. (JEL F34

Evaluating debt repurchases: what are the alternative to investment?.

In this paper a general model of debt repurchases is built which reconciles most of the points raised in the literature on debt buybacks. It is shown that results previously found in the literature can be obtained from this general model and are strongly dependant on assumptions made on its parameters. The condition that determines whether or not buybacks are an attractive solution from the point of the debtor nations is derived. Additionally it is shown that if there are other assets safer than investment, a debt buyback will always lead to an increase in investment and a reduction in the holdings of such other assets. This result holds independently of the source of the resources used for the buyback, unlike previous suggestions. With a buyback out of current resources, optimal reserves levels fall by more than what is used for the buyback, releasing extra resources for investment purposes, while current consumption does not fall. (JEL F34)Debt Overhang; Debt Repurchases; Investment Incentives;

Incentives for cost reducing innovations under quantitative import restraints

The effect of quotas on fmns' incentive to invest in cost-reducing R&D is studied in a two-stage price-setting duopoly. A domestic and a foreign firm choose initially R&D efforts and then set the prices of their differentiated products in the domestic market. With a quota imposed at, or close to, the free-trade level of imports, the domestic fmn faces less competition than under free-trade and chooses to invest less in R&D. Contrarily, the constrained foreign fmn invests more in R&D as the negative strategic effect of a reduction in its cost is now absent. These results differ from the Coumot duopoly case in which R&D expenditures are lower for both fmns. We also show that as the quota becomes more restrictive, the domestic fmn increases and the foreign fmn decreases its expenditures in R&D. Finally, we show that domestic welfare is a1ways higher under free-trade than under any quota regardless of the degree of product substitutability

Implication of AMPK in glucose-evoked modulation of Na,K-ATPase

Background and aims: Na,K-ATPase is an integral membrane protein that maintains the gradients of Na+ and K+, using the energy of ATP hydrolysis, maintaining the ionic gradients that allow electrical activity to occur. It has been demonstrated that, in pancreatic β-cells, Na,K-ATPase is regulated by glucose and that this phenomenon is impaired in glucose intolerant subjects. However, the mechanism underlying glucose-induced modulation of Na,K-ATPase is still unclear. The AMP-activated protein kinase (AMPK) is a molecular key player in energy homeostasis, providing exquisite sensitivity to small changes in intracellular AMP levels and thus to intracellular [ATP]/[ADP] ratio, that is known to activate protein regulatory pathways. Since in pancreatic β-cell, glucose has marked effects on oxidative metabolism and total intracellular ATP and AMP levels, the involvement of AMPK in the cascade of events regulating Na,K-ATPase regulation in pancreatic β-cells was postulated. The aim of this work was to evaluate the putative role of AMPK in the glucose-evoked regulation of Na,K-ATPase activity in the pancreatic β-cell. Materials and methods: Pancreatic -cells from normal (control) or glucose-intolerant Wistar rats (GIR) were isolated and cultured (48h). Cell batches were pre-incubated (30min) with 2.1mM glucose to reach basal activity. Afterwards cells were challenged to 8.4mM glucose for 20min, in the presence or absence of AMPK agonists (AICAR) and antagonists (compound C; CC). ATPase activity was assessed in intact cells by colorimetric quantification of Pi formed in 30min. Na,K-ATPase activity was calculated by the difference between the activities obtained in the absence and in presence the of 1mM ouabain. Results: In basal conditions the activity of Na,K-ATPase from normal and GIR pancreatic β-cell was similar (0.184±0.030 and 0.186±0.020 molPi/min/mgProt, respectively). Challenging the control β-cells with glucose 8.4mM evoked a 62% reduction of Na,K-ATPase activity whereas in GIR β-cells a significantly lower inhibition (40%) was observed. The addition of AICAR 1mM abolished glucose-induced Na,K-ATPase inhibition (0,166±0.011 molPi/min/mg). In control β-cell, the addition of CC 10 μM had no effect on glucose-induced inhibition of Na,K-ATPase. In the contrary, in GIR β-cells it significantly potentiated glucose-evoked inhibition of Na,K-ATPase reaching values similar to that observed in the controls (66%). Conclusions: The AMPK agonist AICAR counteracts the inhibitory action of glucose on Na,K-ATPase of control β-cells whereas CC amplified the glucose-induced inhibition of Na,K-ATPase in GIR β-cells. These results suggest that AMPK plays a central role in the cascade of events underlying glucose-induced modulation of Na,K-ATPase and that the defect must be upstream of AMPK. Finally, abnormal glucose-induced regulation of Na,K-ATPase occurs prior to overt type 2 diabetes and might be a feature in the disease development

Abnormal regulation of Na,K-ATPase in Glucose Intolerant Rats.

Introduction: Glucose is the most important physiological insulin secretagogue. However, the mechanisms underlying glucose-induced insulin release are not fully understood. The role of electrogenic systems such as ionic pumps, to these events remains essentially uninvestigated. Na,K-ATPase, responsible for maintaining Na+ and K+ gradients across the plasma membrane and generates a net outward current, thus changes in its activity may contribute to the early ionic events regulating insulin secretion (Therien and Blostein, 2000). Objective: The aim of this work was to evaluate the regulation of Na,K-ATPase activity by glucose in intact -cells of normal and glucose intolerant (GI) rats and its putative contribution to the regulation of insulin secretion. Material and Methods: Pancreatic -cells, from normal or control or GI rats, were isolated and cultured (48h). Cell batches were pre-incubated (30min) with 2mM glucose to reach basal. Afterwards cells were challenged with glucose in the interval 0-11mM for 60min, for dose-dependence evaluation, or with 8mM glucose for 5-120min, for time-dependence evaluation. ATPase activity was assessed in intact cells by colorimetric quantification of Pi formed in 30min. Na,K-ATPase activity was calculated by the difference between the activities obtained in the absence and in presence the of 1mM ouabain (Costa et al., 2009). Results: In β-cells from normal rats, glucose induced a bimodal regulation of Na,K-ATPase. In the absence of glucose, Na,K-ATPase activity was 0.056±0.015 U/mg. Stimulation with 2mM glucose induced an increase of Na,K-ATPase activity of ~4 fold whereas for [glucose] above 2mM it was observed a significant inhibition of Na,K-ATPase activity (0.061±0.013, 0.080±0.009 and 0.064±0.005 U/mg for 5.6, 8.4 and 11mM glucose, respectively, compared to 0.188±0.035 U/mg observed in 2mM G; n=3-8). β-cells from GI rats does not present this profile; in the absence of glucose, Na,K-ATPase activity was 0.202±0.036 U/mg and no significant differences from this value were observed with the other glucose concentration tested. Addicionally, in β-cells from normal rats, glucose (8mM) induced a time-dependent inhibition, with a biphasic profile, of Na,K-ATPase - it was observed a decrease in the pump activity between 0 and 20min stimulation where it reached a minimum value (77%). For incubation periods over 20min, the pump activity slowly and partially recovered (54%, 55% and 52%, for 30, 60 and 120min, respectively; n=7). In β-cells from GI animals, an less accentuated decrease of Na,K-ATPase activity between 0 ans 20min was also observed (34%), and is not observed further recover in activity. Conclusions: This work demonstrates there Na,K-ATPase is strictly regulated by glucose in pancreatic β-cell. This regulation is unpaired in GI animals. Na,K-ATPase contribution to glucose-induced ionic events and insulin secretion might be relevant and must be explored as a possible therapeutic target in TD2 . 1. Therien AG, Blostein R (2000) Mechanisms of sodium pump regulation. Am J Physiol Cell Physiol 279:C541-C566 2. Costa AR, Real J, Antunes CM, Cruz-Morais J (2009) A new approach for determination of Na,K-ATPase activity: application to intact pancreatic beta-cells. In Vitro Cell Dev Biol Ani

Da educação superior para o mercado de trabalho: a inserção profissional dos licenciados no IPS

A integração efetiva, no mercado de trabalho, dos diplomados com formação académica superior tem despoletado, nos últimos anos, um renovado interesse nas instituições de ensino, nas políticas educativas e de emprego e na sociedade em geral. Com efeito, apesar do crescimento da frequência do ensino superior e do aumento progressivo de diplomados, o atual contexto de crise económica, marcado, essencialmente, pela incerteza, instabilidade e precariedade laboral, tem condicionado o processo de inserção profissional dos jovens que saem da escola para acederem ao mercado de emprego. Neste sentido, para que cada instituição de ensino possa ser mais atuante no processo de transição dos seus diplomados para a vida ativa e, simultaneamente, adaptar a sua oferta formativa, torna-se fundamental acompanhar, de uma forma sistemática, a trajetória profissional dos mesmos. É neste quadro que este trabalho apresenta os resultados do estudo desenvolvido no âmbito do Observatório de Inserção na Vida Ativa do Instituto Politécnico de Setúbal (OIVA/IPS), que tem como objetivo analisar o percurso profissional dos licenciados no IPS, um ano após a obtenção do grau académico, a partir dos resultados de um inquérito por questionário aplicado aos licenciados no IPS no ano letivo 2010/2011. Objetiva-se, igualmente, explanar os resultados atinentes às variáveis do estudo, nomeadamente, a situação profissional e o vínculo laboral dos licenciados empregados, as diferenças de género no acesso ao emprego, os níveis salariais, a caracterização das entidades empregadoras e, a relação existente entre a profissão e a área de formação académica, tendo presente as assimetrias existentes entre as escolas do IPS e, em particular, entre os diversos cursos ministrados. Discutir-se‐á, ainda, e sempre que possível, os resultados obtidos com estudos semelhantes realizados para outras Instituições de Ensino Superior. O presente relatório encontra-se dividido em quatro capítulos principais. No primeiro capítulo é apresentada a revisão da literatura relevante para a discussão da problemática da inserção profissional dos diplomados no mercado de trabalho. Seguidamente, no segundo capítulo, descreve-se a metodologia de investigação, os objetivos e os instrumentos de recolha de dados utilizados. Na terceira parte do relatório procede‐se à análise e discussão dos resultados obtidos nas diversas variáveis em estudo, ao nível do IPS, por escola e curso ministrado. Por fim, no último capítulo destacam-se as principais conclusões apresentando-se ainda algumas reflexões em torno das diferenças existentes entre a situação profissional dos licenciados do IPS

Estudo sobre o conhecimento da população portuguesa acerca de fibras alimentares

Dissertação de Mestrado em Qualidade e Tecnologia AlimentarA associação entre fibra alimentar, benefícios para a saúde e alimentação saudável tem sido objecto de estudo nos últimos anos. A indústria alimentar, para acompanhar o forte interesse demonstrado pelos consumidores, tem colocado cada vez mais à disposição do consumidor novos produtos, ricos em fibra alimentar. De modo a ir de encontro deste enorme interesse e da procura por estes produtos, foi elaborado este trabalho, que teve como principal objectivo avaliar o grau de conhecimento da população portuguesa sobre fibras alimentares e sobre os seus efeitos para a saúde, bem como avaliar os seus hábitos de consumo no que respeita a fibras. Para tal foi efectuado um inquérito por questionário misto 'on-line' tendo sido recebidos um total de 182 inquéritos respondidos válidos. Após o tratamento dos resultados conclui-se que o nível de conhecimento da população acerca das fibras alimentares bem como a quantidade consumida são baixos, tendo em conta a grande importância atribuída às fibras no que respeita ao tratamento e prevenção de diferentes tipos de doenças.ABSTRACT: The association between dietary fiber, health benefits and healthy food has been studied in recent years. The food industry, to accompany the strong interest shown by consumers, has placed at their disposal new products, rich in dietary fiber. In order to meet this huge interest and demand for these products, this work was elaborated, which had as main objective to evaluate the degree of knowledge of the Portuguese population about fiber and its effects on health, as well as evaluating the their consumption habits in respect of fibers. To this end inquiry was carried out by questionnaire mixed "on line" and was received a total of 182 valid inquiries answered. After treatment of the results it is concluded that the level of knowledge of the population about the fiber and the quantity consumed are low, taking into account the great importance given to the fibers in respect to the treatment and prevention of different diseases

The role of commitment and the choice of trade policy instruments

The incentives for governments to impose subsidies and tariffs on R&D and output is analyzed in a differentiated good industry where firms invest in a cost saving technology. When government commitment is credible, subsidies to R&D and output are positive both under Bertrand and Cournot competition. In the absence of government commitment the policy instrument is a tariff under Bertrand, and a subsidy under Cournot, competition. However, welfare under free trade is always greater than imposing a tariff unilaterally, or bilaterally, and hence non-committal under price competition is never an equilibrium. If a government has to choose either a subsidy on R&D (or on output) then, independent of price or quantity competition, it subsidies R&D for low levels of product substitutability and output for higherlevels of substitutability

Development of electrochemical nitrite biosensors using cytochrome c nitrite reductase from Desulfovibrio desulfuricans ATCC 27774

Dissertação apresentada para a obtenção do Grau de Doutor em Química Sustentável pela Universidade Nova de Lisboa, Faculdade de Ciências e TecnologiaREQUIMTE ; Fundação para a Ciência e Tecnologia -(POCI/QUI/58026/2004 and SFRH/BD/28921/2006