THE ANDEAN PRICE BAND SYSTEM: EFFECTS ON PRICES, PROTECTION AND PRODUCER WELFARE

The Andean Community's Price Band System (APBS), introduced in 1995, had the announced goal of reducing domestic price instability by buffering fluctuations in international prices through use of a variable import tariff. This paper evaluates the effects of the Andean Price Band System on domestic producer price variability, levels of nominal protection and changes in producer welfare. Application is made to four important food products - maize, rice, sugar and milk - in Colombia, Ecuador and Venezuela, from the period 1990 to 1998. The effects of the APBS on producer price variability are analyzed through 1) comparing coefficients of variation of detrended, monthly deseasonalized real prices before and after the harmonization of the APBS in 1995, and 2) variance decomposition of real domestic prices. For Colombia and Ecuador, the APBS is shown to have successfully reduced real price instability below levels of instability which existed prior to its introduction. Real exchange rate instability also decreased sharply in these two countries following introduction of the APBS. In Venezuela, real price instability is shown to have increased following introduction of the APBS, while real exchange rate instability was unchanged. The APBS' effects on producer price protection are examined through estimation of average nominal protection coefficients for the twelve country-commodity combinations identified above before and after the introduction of the APBS. Results show that in all three countries and four virtually all products, the APBS contributed to increased producer protection. Finally, this paper uses a variant of the Newbery-Stiglitz approach to calculate efficiency benefits due to risk reduction among producers and the transfer benefits created by redistributing income among producers, consumers and government. The results show that the risk reduction benefits created by the APBS are small. Similarly, the income transfer effects, though larger, are also low, and both contribute to generally low levels of estimated producer welfare effects. Overall, the paper concludes that the APBS has been of limited usefulness as a policy instrument designed to reduce producer price variability in an economically efficient manner.Andean Community, price band system, agricultural prices, price stabilization, Demand and Price Analysis,

Vacuum quark condensate, chiral Lagrangian, and Bose-Einstein statistics

In a series of articles it was recently claimed that the quantum chromodynamic (QCD) condensates are not the properties of the vacuum but of the hadrons and are confined inside them. We point out that this claim is incompatible with the chiral Lagrangian and Bose-Einstein statistics of the Goldstone bosons (pions) in chiral limit and conclude that the quark condensate must be the property of the QCD vacuum.Comment: 4 Pages, To appear in Phys. Lett.

Comparison between the method of determining the power and axis of the cylinder by the Jackson cross cylinder technique and a Lebensohn\u27s type astigmatic chart

The purpose of this study is to make a comparison between the Jackson Cross Cylinder (J.C.C.) technique of determining the axis and power of the far cylinder with a Lebensohn\u27s type of astigmatic chart. The authors of this paper would like to know if the Lebensohn\u27s type astigmatic chart can be substituted for the Jackson Cross Cylinder test

Effects of the light regime on nutrient assimilation by phytoplankton in the Baja California and northwest Africa upwelling systems

The ability of natural phytoplankton assemblages in the Baja California and northwest Africa upwelling regions to assimilate nitrate, ammonium and silicic acid at simulated in situ light intensity and in the dark, was determined in 6 hr tracer experiments using the stable isotopes 15N and 30Si. Nitrate was almost never taken up in the dark, but dark uptake rates of ammonium and silicic acid ranged from zero to values equal to those measured at saturating light intensity...

Management of an Accessory Bile Duct Leak Following Pancreaticoduodenectomy: A Novel Approach Utilizing a Percutaneous and Endoscopic Rendezvous.

Biliary leaks are uncommon but morbid complications of pancreaticoduodenectomies, which have historically been managed with percutaneous drainage, reoperation, or a combination of both. We report a de novo percutaneous-endoscopic hepaticojejunostomy from an anomalous right hepatic duct injured during pancreaticoduodenectomy to the afferent bowel limb. The percutaneous-endoscopic hepaticojejunostomy was stented to allow for tract formation with successful stent removal after 5.5 months. One year after the creation of the percutaneous-endoscopic hepaticojejunostomy, the patient remains clinically well without evidence of biliary leak or obstruction

Vortex pinning by meandering line defects in planar superconductors

To better understand vortex pinning in thin superconducting slabs, we study the interaction of a single fluctuating vortex filament with a curved line defect in (1+1) dimensions. This problem is also relevant to the interaction of scratches with wandering step edges in vicinal surfaces. The equilibrium probability density for a fluctuating line attracted to a particular fixed defect trajectory is derived analytically by mapping the problem to a straight line defect in the presence of a space and time-varying external tilt field. The consequences of both rapid and slow changes in the frozen defect trajectory, as well as finite size effects are discussed. A sudden change in the defect direction leads to a delocalization transition, accompanied by a divergence in the trapping length, near a critical angle.Comment: 9 pages, 9 figure

The Aviation System Analysis Capability Airport Capacity and Delay Models

The ASAC Airport Capacity Model and the ASAC Airport Delay Model support analyses of technologies addressing airport capacity. NASA's Aviation System Analysis Capability (ASAC) Airport Capacity Model estimates the capacity of an airport as a function of weather, Federal Aviation Administration (FAA) procedures, traffic characteristics, and the level of technology available. Airport capacity is presented as a Pareto frontier of arrivals per hour versus departures per hour. The ASAC Airport Delay Model allows the user to estimate the minutes of arrival delay for an airport, given its (weather dependent) capacity. Historical weather observations and demand patterns are provided by ASAC as inputs to the delay model. The ASAC economic models can translate a reduction in delay minutes into benefit dollars

RELEVANCE OF ETHYL LACTATE AMONG THE CACHAÇA ESTERS

ABSTRACT The advancement in the technology of cachaça ─ sugarcane spirit produced in the Brazilian territory ─ has led to the search for parameters that allow the improvement of its chemical characterization and sensory specificities. Esters are important aroma agents, but their routine monitoring, as endorsed in Brazilian legislation, is restricted to the quantification of ethyl acetate, which is formed through the metabolism of yeast (Saccharomyces cerevisiae). However, being produced in a rural environment using fresh cane juice, fermentation of “cachaça de alembic” involves the presence and activity of lactic acid-producing bacteria, making the presence of ethyl lactate among the cachaça esters predictable. In this work, the levels of ethyl lactate and ethyl acetate were compared in 247 samples, corresponding to 56 brands produced in eleven Brazilian states. Ethyl lactate was found in levels that significantly alter the result of the quantitative participation of esters in the composition of cachaça. This fact is especially relevant considering that lactic acid bacteria are GRAS and widely recognized as a resource for improving the sensory quality of wines and other alcoholic beverages. Thus, studies on the contribution of lactic acid bacteria to the sensory quality of cachaça should be encouraged. Ethyl lactate, in addition to signaling a chemical specificity naturally occurring in cachaça, is a marker of other possible chemical and sensory peculiarities whose research should be stimulated.RESUMEN Los avances en la tecnología de la cachaça - aguardiente de caña de azúcar producida en el territorio brasileño - ha dado lugar a la búsqueda de parámetros que permitan mejorar su caracterización química y especificidades sensoriales. Los ésteres son agentes aromáticos importantes, pero su control rutinario se limita a la cuantificación del contenido de acetato de etilo, que proviene del metabolismo de las levaduras (Saccharomyces cerevisiae). Sin embargo, al producirse en un medio rural a partir de jugo fresco de caña de azúcar, la fermentación conlleva la presencia y actividad de bacterias lácticas, lo que hace predecible la participación de lactato de etilo entre los ésteres da bebida. En este trabajo se compararon los contenidos de lactato de etilo y acetato de etilo en 247 muestras de 56 marcas producidas en once estados brasileños. Fue encontrada la presencia de lactato de etilo en niveles que cambian significativamente el resultado de la participación cuantitativa de los ésteres en la composición de la cachaza. Este hecho es especialmente relevante si se tiene en cuenta que las bacterias del ácido láctico son GRAS y se han utilizado como recurso para mejorar la calidad sensorial de los vinos y otras bebidas alcohólicas. Por ello, es importante impulsar estudios sobre la contribución de las bacterias del ácido láctico a la calidad sensorial de la cachaza. El lactato de etilo, además de señalar una especificidad química natural en la cachaza, es un marcador de otras posibles peculiaridades químicas y sensoriales cuya investigación debe fomentarse.RESUMO O avanço na tecnologia da cachaça ─ aguardente de cana produzida no território brasileiro ─ tem ensejado a busca por parâmetros que permitam aprimorar sua caracterização química e especificidades sensoriais. Os ésteres são importantes agentes de aroma, mas seu monitoramento rotineiro, conforme referendado na legislação brasileira, restringe-se à quantificação do teor de acetato de etila, que advém do metabolismo das leveduras (Saccharomyces cerevisiae). No entanto, sendo produzida em ambiente rural a partir do caldo de cana fresco, a fermentação da “cachaça de alambique” enseja a presença e atividade de bactérias produtoras do ácido lático, tornando previsível a participação do lactato de etila entre os ésteres da cachaça. Nesse trabalho, foram comparados os teores de lactato de etila e acetato de etila em 247 amostras correspondentes a 56 marcas produzidas em onze estados brasileiros.  Os resultados evidenciaram a presença do lactato de etila em teores que alteram significativamente o resultado da participação quantitativa dos ésteres na composição da cachaça. Tal fato é especialmente relevante tendo em vista que bactérias láticas são GRAS e têm sido empregadas como recurso para aprimoramento da qualidade sensorial de vinhos e outras bebidas alcoólicas. Assim, é importante estimular estudos sobre a contribuição das bactérias láticas para a qualidade sensorial da cachaça. O lactato de etila, além de sinalizar uma especificidade química de ocorrência natural na cachaça, é um marcador de outras possíveis peculiaridades químicas e sensoriais cuja pesquisa deve ser estimulada

A radiological assessment of nuclear power and propulsion operations near Space Station Freedom

Scenarios were identified which involve the use of nuclear power systems in the vicinity of Space Station Freedom (SSF) and their radiological impact on the SSF crew was quantified. Several of the developed scenarios relate to the use of SSF as an evolutionary transportation node for lunar and Mars missions. In particular, radiation doses delivered to SSF crew were calculated for both the launch and subsequent return of a Nuclear Electric Propulsion (NEP) cargo vehicle and a Nuclear Thermal Rocket (NTR) personnel vehicle to low earth orbit. The use of nuclear power on co-orbiting platforms and the storage and handling issues associated with radioisotope power systems were also explored as they relate to SSF. A central philosophy in these analyses was the utilization of a radiation dose budget, defined as the difference between recommended dose limits from all radiation sources and estimated doses received by crew members from natural space radiations. Consequently, for each scenario examined, the dose budget concept was used to identify and quantify constraints on operational parameters such as launch separation distances, returned vehicle parking distances, and reactor shutdown times prior to vehicle approach. The results indicate that realistic scenarios do not exist which would preclude the use of nuclear power sources in the vicinity of SSF. The radiation dose to the SSF crew can be maintained at safe levels solely by implementing proper and reasonable operating procedures