The Political Economy of Exchange Rate Policies in Argentina

This paper identifies three periods in Argentine exchange rate policy, corresponding with different development strategies and political coalitions. The first, periodic adjustments to a pegged rate until the mid-1970s, accompanied an Import Substitution Industrialization approach and a redistribution of income from agrarian to industrial production during an era of strong labor union influence. A second period, from the mid-1970s, marked by accelerated devaluations, represented efforts by both military and civilian governments to meet the demands of their respective constituencies while maintaining capital flows from abroad; these efforts culminated in hyperinflation. A third period, beginning in the early 1990s, was notable for exchange rate stability, based on the Convertibility Plan, as a broad consensus emerged that the exchange rate should be used for containing inflation rather than engaging in redistribution among domestic interest groups. The authors conclude that additional innovations in Argentina`s monetary and exchange rate policies may eventually be necessary.

Joint Location and Dispatching Decisions for Emergency Medical Service Systems

Emergency Medical Service (EMS) systems are a service that provides acute care and transportation to a place for definitive care, to people experiencing a medical emergency. The ultimate goal of EMS systems is to save lives. The ability of EMS systems to do this effectively is impacted by several resource allocation decisions including location of servers (ambulances), districting of demand zones and dispatching rules for the servers. The location decision is strategic while the dispatching decision is operational. Those two decisions are usually made separately although both affect typical EMS performance measures. The service from an ambulance is usually time sensitive (patients generally want the ambulances to be available as soon as possible), and the demand for service is stochastic. Regulators also impose availability constraints, the most generally accepted being that 90\% of high priority calls (such as those related to cardiac arrest events) should be attended to within 8 minutes and 59 seconds. In the case of minimizing the mean response time as the only objective, previous works have shown that there are cases in which it might not be optimal to send the closest available server to achieve the minimum overall response time. Some researchers have proposed integrated models in which the two decisions are made sequentially. The main contribution of this work is precisely in developing the integration of location and dispatching decisions made simultaneously. Combining those decisions leads to complex optimization models in which even the formulation is not straightforward. In addition, given the stochastic nature of the EMS systems the models need to have a way to represent their probabilistic nature. Several researchers agree that the use of queuing theory elements in combination with location, districting and dispatching models is the best way to represent EMS systems. Often heuristic/approximate solution procedures have been proposed and used since the use of exact methods is only suitable for small instances. Performance indicators other than Response Time can be affected negatively when the dispatching rule is sending the closest server. For instance, there are previous works claiming that when the workload of the servers is taken into account, the nearest dispatching policy can cause workload imbalances. Therefore, researchers mentioned as a potential research direction to develop solution approaches in which location, districting and dispatching could be handled in parallel, due to the effect that all those decisions have on key performance measures for an EMS system. In this work the aim is precisely the development of an optimization framework for the joint problem of location and dispatching in the context of EMS systems. The optimization framework is based on meta heuristics. Fairness performance indicators are also considered, taking into account different points of view about the system, in addition to the standard efficiency criteria. Initially we cover general aspects related to EMS systems, including an overall description of main characteristics being modeled as well as an initial overview of related literature. We also include an overall description and literature review with focus on solution methodologies for real instances, of two related problems: the $p$-median problem and the maximal covering location problem (MCLP). Those two problems provide much of the basic structure upon which the main mathematical model integrating location and dispatching decisions is built later. Next we introduce the mathematical model (mixed-integer non-linear problem) which has embedded a queuing component describing the service nature of the system. Given the nature of the resulting model it was necessary to develop a solution algorithm. It was done based on Genetic Algorithms. We have found no benefit on using the joint approach regarding mean Response Time minimization or Expected Coverage maximization. We concluded that minimizing Response Time is a better approach than maximizing Expected Coverage, in terms of the trade-off between those two criteria. Once the optimization framework was developed we introduced fairness ideas to the location/allocation of servers for EMS systems. Unlike the case of Response Time, we found that the joint approach finds better solutions for the fairness criteria, both from the point of view of internal and external costumers. The importance of that result lies in the fact that people not only expect the service from ambulances to be quick, but also expect it to be fair, at least in the sense that any costumer in the system should have the same chances of receiving quick attention. From the point of view of service providers, balancing ambulance workloads is also desirable. Equity and efficiency criteria are often in conflict with each other, hence analyzing trade-offs is a first step to attempt balancing different points of view from different stakeholders. The initial modeling and solution approach solve the problem by using a heuristic method for the overall location/allocation decisions and an exact solution to the embedded queuing model. The problem of such an approach is that the embedded queuing model increases its size exponentially with relation to the number of ambulances in the system. Thus the approach is not practical for large scale real systems, say having 10+ ambulances. Therefore we addressed the scalability problem by introducing approximation procedures to solve the embedded queuing model. The approximation procedures are faster than the exact solution method for the embedded sub-problem. Previous works mentioned that the approximated solutions are only marginally apart from the exact solution (1 to 2\%). The mathematical model also changed allowing for several ambulances to be assigned to a single station, which is a typical characteristic of real world large scale EMS systems. To be able to solve bigger instances we also changed the solution procedure, using a Tabu Search based algorithm, with random initialization and dynamic size of the tabu list. The conclusions in terms of benefits of the joint approach are true for bigger systems, i.e. the joint approach allows for finding the best solutions from the point of view of several fairness criteria

Study of the apsidal precession of the Physical Symmetrical Pendulum

We study the apsidal precession of a Physical Symmetrical Pendulum (Allais' precession) as a generalization of the precession corresponding to the Ideal Spherical Pendulum (Airy's Precession). Based on the Hamilton-Jacobi formalism and using the technics of variation of parameters along with the averaging method, we obtain approximate solutions, in terms of which the motion of both systems admits a simple geometrical description. The method developed in this paper is considerably simpler than the standard one in terms of elliptical functions and the numerical agreement with the exact solutions is excellent. In addition, the present procedure permits to show clearly the origin of the Airy's and Allais' precession, as well as the effect of the spin of the Physical Pendulum on the Allais' precession. Further, the method can be extended to the study of the asymmetrical pendulum in which an exact solution is not possible anymore.Comment: 20 pages, 8 figures, LaTeX2

Carbon Dioxide (CO2) Emissions in Latin America: Looking for the Existence of Environmental Kuznets Curves

We estimated environmental Kuznets curve (EKC) for carbon dioxide for 16 Latin American countries using nonparametric, semi-parametric, and parametric specifications. Results indicated that most of the Latin American countries are still in the rising portion of the EKC with respect to CO2 pollution.Environmental Economics and Policy,

Stability of Nitrogen in Planetary Atmospheres in Contact with Liquid Water

Molecular nitrogen is the most commonly assumed background gas that supports habitability on rocky planets. Despite its chemical inertness, nitrogen molecules are broken by lightning, hot volcanic vents, and bolide impacts, and can be converted into soluble nitrogen compounds and then sequestered in the ocean. The very stability of nitrogen, and that of nitrogen-based habitability, is thus called into question. Here we determine the lifetime of molecular nitrogen vis-à-vis aqueous sequestration, by developing a novel model that couples atmospheric photochemistry and oceanic chemistry. We find that HNO, the dominant nitrogen compound produced in anoxic atmospheres, is converted to N2O in the ocean, rather than oxidized to nitrites or nitrates as previously assumed. This N₂O is then released back into the atmosphere and quickly converted to N₂. We also find that the deposition rate of NO is severely limited by the kinetics of the aqueous-phase reaction that converts NO to nitrites in the ocean. Putting these insights together, we conclude that the atmosphere must produce nitrogen species at least as oxidized as NO₂ and HNO₂ to enable aqueous sequestration. The lifetime of molecular nitrogen in anoxic atmospheres is determined to be >1 billion years on temperate planets of both Sun-like and M dwarf stars. This result upholds the validity of molecular nitrogen as a universal background gas on rocky planets

Análisis tecnico-economico del uso de las diferentes tecnicas de cañoneo en los campos operados por petro produccion

El presente trabajo es un Análisis Técnico - Económico del uso de las diferentes técnicas de cañoneo en los campos operados por Petroproducción. La importancia de que la operación de cañoneo resulte más eficiente radica básicamente en las penetraciones alcanzadas y por ende en las razones de productividades estimadas a partir de estas, sin dejar de tomar en cuenta el daño total generado por las diferentes técnicas de estudio. Para realizar un adecuado análisis de los diferentes sistemas de cañoneo, este trabajo muestra fundamentos teóricos y técnicos, selección de pozos y análisis económicos; encasillados en seis capítulos

Agentes causales de las principales enfermedades dérmicas y sus factores condicionantes en caninos distrito de Villa Maria del Triunfo - Lima, enero - mayo del 2017

El presente estudio se realizó con el objetivo de determinar los principales agentes causales de enfermedades dérmicas en canes atendidos en la clínica veterinaria “Huellitas de mi Cachorro” en el distrito de Villa María del Triunfo en la ciudad de la Lima – Perú. Durante el periodo de enero a mayo se evaluaron 150 fichas clínicas de caninos a los cuales se les practicaron raspado y cultivo bacteriológico. Se identificaron pulgas (Ctenocephalides spp.) con 44.00%, sarna sarcóptica (19.33%) micosis (13.34%) y cuadros de alergia (11.33%). Estos agentes causales traen una serie de problema a los canes y también a los dueños, ya que pueden transmitir enfermedades zoonóticas, para lo cual se propone realizar un control preventivo de estas enfermedades dérmicas. La presentación coincide con los meses de mayor radiación solar y humedad relativa alta.The present study was carried out with the objective of determining the main causal agents of dermal diseases in dogs treated in the veterinary clinic ""Huellitas de mi Cachorro"" in the district of Villa María del Triunfo in the city of Lima - Peru during the period of January to May 150 clinical canines of canines were evaluated, which were scraped and bacteriological culture. Fleas (Octenocephalides spp.) were identified with 44.00%, sarcoptic mange (19.33%) mycosis (13.34%) and allergy symptoms (11.33%). These causal agents bring a series of problems to the dogs and also to the owners, since they can transmit zoonotic diseases, for which purpose it is proposed to carry out a preventive control of these dermal diseases. The presentation coincides with the months of highest solar radiation and high relative humidity.Tesi