Valuing Noise Level Reductions in a Residential Location Context

The noise levels measured in metropolitan streets are on many occasions over the norms but the consequences of this as a health hazard are only starting to be questioned; this is obviously worse in the large cities of the second and third worlds. A stated preference (SP) experiment was designed to estimate the willingness-to-pay (WTP) for reducing the noise level in a group based residential location context. Important issues were the proper definition of the context and the variable metric for the environmental attribute. The experiment considered variations of the attributes travel time to work, monthly house rent, position of the dwelling with respect to the sun and subjective noise level inside it; objective levels were also measured after the experiment. With this data we estimated Multinomial Logit and Mixed Logit (ML) models based on a consistent microeconomic framework, with linear and non-linear utility functions and allowing for various stratifications of the data. The more flexible ML models also allow to treat the repeated observations problem common to SP data and, as expected, gave a better fit to the data. Based on these models we estimated subjective values of time, that were consistent with previous values obtained in the country, and also sensible values for the WTP for reductions in the subjective noise level at a given location

Prefacio

Prefacio a las Actas de XVI Congreso Chileno de Ingeniería de Transport

Lipoic acid inhibits leptin secretion and Sp1 activity in adipocytes

Lipoic acid (LA) is an antioxidant with therapeutic potential on several diseases such as diabetes and obesity. Hyperleptinemia and oxidative stress play a major role in the development of obesity-linked diseases. The aim of this study was to examine in vivo and in vitro the effects of LA on leptin production, as well as to elucidate the mechanisms and signalling pathways involved in LA actions. Methods and results: Dietary supplementation with LA decreased both circulating leptin, and adipose tissue leptin mRNA in rats. Treatment of 3T3-L1 adipocytes with LA caused a concentration-dependent inhibition of leptin secretion and gene expression. Moreover, LA stimulated the anaerobic utilization of glucose to lactate, which negatively correlated with leptin secretion. Furthermore, LA enhanced phosphorylation of Sp1 and inhibited Sp1 transcriptional activity in 3T3-L1 adipocytes. Moreover, LA inhibited Akt phosphorylation, a downstream target of phosphatidylinositol 3-kinase (PI3K). Treatment with the PI3K inhibitor LY294002 mimicked LA actions, dramatically inhibiting both leptin secretion and gene expression and stimulating Sp1 phosphorylation. Conclusion: All of these data suggest that the phosphorylation of Sp1 and the accompanying reduced DNA-binding activity are likely to be involved in the inhibition of leptin induced by LA, which could be mediated in part by the abrogation of the PI3K/Akt pathway

Effect of ultra high temperature (UHT) treatment on coffee brew stability

In this work, the influence of an Ultra High Temperature (UHT) treatment on chemical and sensory composition of Arabica coffee brews for a longer shelf-life has been studied. A temperature of 120 degrees C for 2 s allows to obtain a microbiologically safe coffee brew, good valued from the sensory point of view. The behavior of the UHT vs non UHT treated coffee brew was followed throughout 120 days of storage at 4 degrees C. The UHT treatment keeps the typical acidity of the brews longer, delaying and softening the pH decrease and the development of sourness, which is one of the main causes for the rejection of stored coffee brews. The UHT treatment hardly affects the concentrations of caffeine and trigonelline, and of some phenolic compounds such as 5-caffeoylquinic (5-CQA), caffeic or ferulic acids. Sixteen key odorants and staling volatiles were analyzed by HS-GC-MS and lower changes were observed in the UHT treated coffee brew throughout storage. Higher DPPH center dot scavenging activity was observed in the UHT treated coffee brew from days 60 to 120. In conclusion, the application of an UHT treatment is proposed to extend the shelf-life (up to 60 days) of stored coffee brews

Universidad y sociedad: comunicación e integración en empresas e instituciones públicas y organizaciones no lucrativas. Nuevos avances

Depto. de Teorías y Análisis de la ComunicaciónFac. de Ciencias de la InformaciónFALSEsubmitte

Universidad y sociedad: comunicación e integración en empresas e instituciones públicas y organizaciones no lucrativas: innovación y progreso

Depto. de Teorías y Análisis de la ComunicaciónFac. de Ciencias de la InformaciónFALSEsubmitte

Prefacio

Prefacio a las Actas de XVI Congreso Chileno de Ingeniería de Transport

Cost and fare estimation for the bus transit system of Santiago

This paper studies the costs of the transit system of Santiago, Chile, and proposes pricing schedules to finance it considering a fixed amount of subsidy. We estimate a cost function for the firms providing bus services in Santiago and study their industrial structure. We also estimate a demand model using aggregate data, which delivers information on the demand price elasticity and the effect of other variables related to the supply (e.g., capacity and frequency). Finally, we compute four pricing schedules: uniform price with and without subsidy and two-part tariffs with and without subsidy. Our results show that: (i) the industry exhibits economies of scale when considering both demand-oriented and supply-oriented output measures; (ii) measures of technical efficiency are consistent with the observed exit of firms from the market; (iii) the budget-balanced fare without subsidy is higher than the actual fare, suggesting that subsidies are justified; (iv) the budget-balanced fare with subsidy is higher than the actual fare, suggesting that subsidies are insufficient; (v) two-part tariffs either with or without subsidy are the most effective means of increasing bus travel demand and user welfare; and (vi) a menu of tickets with two options (a uniform price and a two-part tariff) is a Pareto-improving pricing schedule that balances the budget and increases bus travel demand

Temporal analysis of fare evasion in Transantiago: A socio-political view

Although fare evasion is a common problem in transport systems worldwide, the level of fare evasion experienced in Transantiago is considerably higher than the global average. This study aims to identify how social, political, and cultural components may affect levels of fare evasion experienced to complement and broaden the current research lines. A longitudinal econometric analysis is performed to determine the impacts of transport system variables (bus fare, ticket inspection, number of paid zones, and quality), macroeconomic variables (unemployment and informal employment), and socio-political variables (Transantiago and government approval, reference to scandals in the media, and general trust/confidence experimented at social level). Socio-political variables are included under the assumption that a negative perception regarding these variables may hinder the willingness of users to pay the transport fare. Results confirm existence of a positive autoregressive effect, suggesting a contagious effect in behaviour. An increase in level of inspection reduces fare evasion and an increase in bus fares increases fare evasion. New findings of this study include introduction of government approval and confidence/trust towards political and economic institutions and the ruling class as variables with a contrary effect towards fare evasion, i.e. a decrease in government approval and confidence/trust increases fare evasion