Production of basic potato seed minitubers in substrate and different nitrogen rates

The optimal dose of nitrogen (N) in potato crop depends on the production system. The objective of this study was to determine the optimal dose of N for the production of basic potato seed minitubers and evaluate the effect of N rates on physiological and nitrogen indices in the youngest fully developed leaf (fourth leaf) and in the oldest leaf of the plants at 60 days after planting. The experiment was conducted in a greenhouse at the Departamento de Fitotecnia da Universidade Federal de Viçosa. The treatments consisted of five N rates (0, 45, 90, 180 and 360 mg dm-3), with 10% of each dose applied at planting and the remainder through irrigation water, daily, for 30 days. The nitrogen rates positively influenced the physiological indices (length, width, leaf area, number of leaves, fresh mass and dry mass) and nitrogen (level and content of N and N-NO³ in the dry mass and SPAD) both in the fourth leaf and in the oldest leaf. Likewise, the N rates positively influenced the number and mass of harvested tubers. The largest number (5.44 tubers/plant) and the maximum mass of tubers (243.5 g/plant) were obtained with 360.0 and 332.9 mg N dm-3, respectively. Therefore, the mass and number of tubers were not optimized by the same N rate. The critical SPAD index was 38.8 in the fourth leaf, which was more sensitive to the effect of N rates than the oldest leaf.

Efectos de la suplementación con glutamina sobre el sistema antioxidante y la peroxidación lipídica en pacientes críticos con nutrición parenteral

INTRODUCTION In the critically ill patient, there is a continuous production of reactive oxygen species (ROS) that need to be neutralized to prevent oxidative stress (OS). Quantitatively speaking, the glutathione system (GSH) is the most important anti-oxidant endogenous defense. To increase it, glutamine supplementation has been shown to be effective by protecting against the oxidative damage and reducing the morbimortality. OBJECTIVE To assess the effect of adding an alanylglutamine dipeptide to PN on lipid peroxidation lipidica and glutathione metabolism, as well as its relationship with morbidity in critically ill patients. METHODS Determination through spectrophotometry techniques of glutathione peroxidase, glutathione reductase, total glutathione, and maloniladdehyde at admission adn after seven days of hospitalization at the Intensive Care Unit (ICU) in 20 patients older than 18 years on parenteral nutrition therapy. RESULTS The group of patients receiving parenteral nutrition with glutamine supplementation had significant increases in total glutathione (42.35+/-13 vs 55.29+/-12 micromol/l; p<0.05) and the enzymatic activity of glutathione peroxidasa (470+/-195 vs 705+/-214 micromol/l; p<0.05) within one week of nutritional therapy, whereas the group on conventional parenteral nutrition did not show significant changes of any of the parameters studied (p>0.05). However, both mortality and ICU stay were not different between the study group, whereas the severity (assessed by the SOFA score) was lower in the group of patients receiving glutamine (SOFA 5+/-2 vs 8+/-1.8; p<0.05). CONCLUSIONS Glutamine intake in critically ill patients improves the antioxidant defenses, which leads to lower lipid peroxidation and lower morbidity during admission at the ICU.

Teatro y vida cotidiana

El teatro es un arte que, a diferencia de otras manifestaciones, contiene en sí una paradoja: el actor, en una representación, es al mismo tiempo creador y creación, es artista y obra de arte. De alguna manera, su vida se expone en el escenario, pero de un modo distinto a cómo aparece fuera de él. El teatro y la vida mantienen una relación que se expresa en el cuerpo del actor y descifra su ser dentro y fuera del escenario; pensarla supondría organizar una propuesta sobre un modo de hacer el teatro y de vivir la vida. Explicar aquello de que la vida es un teatro al tiempo de que el teatro es un arte vivo, transitar por la relación teatro-vida dentro del ámbito de la cultura humana, es una exploración semiótica de la relación verdad-mentira, o mejor, de la relación revelación-ocultamiento. El presente texto intenta responder a la pregunta: ¿Cuál es el lenguaje específico del teatro como arte de representación y como hecho de comunicación, y cómo se relaciona éste ámbito de la vida cotidiana? El teatro, además de un arte, es un hecho de represtación que crea signos, es un espacio definido a través de un actor, que tienen existencia y significación por sí mismos dentro de una realidad, y que están referidos a otra realidad. De ahí que, señala el autor, el teatro es también un hecho de comunicación que objetiva la relación entre el emisor y el receptor mediante un lenguaje que le es particular.

Frontiers of the New Economic Geography

This paper presents an overview of recent development in the new economic geography (NEG), and discusses possible directions of its future development. Since there already exist several surveys on this topic, we focus on the selected features of the NEG which are important yet have attracted insufficient attention, and also on the recent refinements and extensions of the framework.

Transport Development and the Evolution of Economic Geography

In this paper, based on the recent advances in the new economic geography (e.g., Fujita, Krugman and Venables [12]), we analyze impacts of transport costs on the spatial patterns of economic agglomeration. We first identify prototypes from the existing models, and explain the mechanism of how transport costs influence the balance between economic forces of agglomeration and dispersion. We then investigate the transformation of the agglomeration/dispersion patterns given gradually decreasing transport costs for different goods.

Economies of Transport Density and Industrial Agglomeration

This paper develops a model of a spatial economy in which interregional trade patterns and the structure of the transport network are determined endogenously as a result of the interaction between industrial location behavior and increasing returns in transportation, in particular, economies of transport density. The traditional models assume either the structure of the transport network or industrial location patterns, and hence, they are unable to explain the interdependence of the two. It is shown that economies of transport density can be the primary source of industrial localization.

The IDE geographical simulation model : predicting long-term effects of infrastructure development projects

It is important to be able to predict changes in the location of populations and industries in regions that are in the process of economic integration. The IDE Geographical Simulation Model (IDE-GSM) has been developed with two major objectives: (1) to determine the dynamics of locations of populations and industries in East Asia in the long-term, and (2) to analyze the impact of specific infrastructure projects on the regional economy at sub-national levels. The basic structure of the IDE-GSM is introduced in this article and accompanied with results of test analyses on the effects of the East West Economic Corridor on regions in Continental South East Asia. Results indicate that border costs appear to play a big role in the location choice of populations and industries, often a more important role than physical infrastructures themselves.

Contents

2009年度調査研究報告書

Introduction New Challenges in New Economic Geography

2009年度調査研究報告書

Chapter 1 Market Access and Intermediate Goods Trade

This paper examines a distinctive feature of intermediate goods trade which the traditional gravity equation fails to capture, i.e., intermediate goods trade is positively related not only to the importing country's demand for finished goods but also to its neighbors' demand for finished goods. We regress a gravity equation for finished goods trade in the first step. Then, introducing the importing country's access to the total demand for finished goods which is calculated by using the estimates in the first step, we regress our gravity equation for trade in intermediate goods. Our regression results confirm such a feature of intermediate goods trade. Using the results of the regression, we simulate how the rise of US consumers' demand for finished goods affects the total imports and exports of intermediate goods in each country.

Chapter 2 Equilibrium locations of upstream and downstream firms

This paper explores the interaction between upstream firms and downstream firms in a two-region general equilibrium model. In many countries, lower tariff rates are set for intermediate manufactured goods and higher tariff rates are set for final manufactured goods. The derived results imply that such settings of tariff rates tend to preserve a symmetric spread of upstream and downstream firms, and continuing tariff reduction may cause core-periphery structures. In the case in which the circular causality between upstream and downstream firms is focused as agglomeration forces, the present model is fully solved. Thus, we find that (1) the present model displays, at most, three interior steady states, (2) when the asymmetric steady-states exist, they are unstable and (3) location displays hysteresis when the transport costs of intermediate manufactured goods are sufficiently high.

Chapter 3 Knowledge Exchanges and Innovation in Connected Firms: Evidence from Upstream-Downstream Relationships

This paper proposes evidences for linking innovation and knowledge exchanges in developing economies towards a comprehensive theory of new economic geography in the knowledge based spatial economy. Firms which dispatched engineers to customers achieved more innovations than firms which did not. Mutual sharing of knowledge also stimulates innovations. A just-in-time relationship is effective for dealing with upgrading production process. But such strong complementarities with partners are not effective for product innovation.. These evidences support the hypothesis that face-to-face communication and complementarities among production linkages have different roles in knowledge creation.

Chapter 4 The Challenges in Developing Realistic NEG Simulation Models for East Asia

This chapter attempts to identify some important issues in developing realistic simulation models based on new economic geography, and it suggests a direction for solving the difficulties. Specifically, adopting the IDE Geographical Simulation Model (IDE-GSM) as an example, we discuss some problems in developing a realistic simulation model for East Asia. The first and largest problem in this region is the lack of reliable economic datasets at the sub-national level, and this issue needs to be resolved in the long term. However, to deal with the existing situation in the short term, we utilize some techniques to produce more realistic and reliable simulation models. One key compromise is to use a 'topology' representation of geography, rather than a 'mesh' or 'grid' representation or simple 'straight lines' connecting each city which are used in many other models. In addition to this, a modal choice model that takes into consideration both money and time costs seems to work well.

Chapter 5 Product Differentiation versus Geographical Differentiation: Evidence from the Pork Processing Industry in China

This chapter attempts to identify whether product differentiation or geographical differentiation is the main source of profit for firms in developing economies by employing a simple idea from the recently developed method of empirical industrial organization. Theoretically, location choice and product choice have been considered as analogues in differentiation, but in the real world, which of these strategies is chosen will result in an immense difference in firm behavior and in the development process of the industry. Development of the technique of empirical industrial organization enabled us to identify market outcomes with endogeneity. A typical case is the market outcome with differentiation, where price or product choice is endogenously determined. Our original survey contains data on market location, differences in product types, and price. The results show that product differentiation rather than geographical differentiation mitigates pressure on price competition, but 70 per cent secures geographical monopoly.

Shrinking population and the urban hierarchy

This paper examines whether population shrinkage leads to changes in urban hierarchy in terms of their relative size and function from the standpoint of the new economic geography. We find some salient patterns in which small cities in the agglomeration shadow become relatively bigger as medium industries spill over on them. This appears to be quite robust against a variation in the rate of natural change among cities. Thus, rank-size relationship and the urban hierarchy are partly disrupted as population shrinks. Regarding the welfare of the residents, a lower demand for land initially causes rent to go down, which boosts the utility. However, the illusion is short-lived because markets soon begin to shrink and suppress wages. We also find that it is better to maintain a slow pace of overall population decline in the long-term perspective. More importantly, it is crucial to sustain the relative livability of smaller cities to minimize the overall loss of utility.