The influence of shell species and size on the shell selection pattern of Paguristes tortugae (Decapoda, Diogenidae) from Anchieta Island (Ubatuba, Brazil)

Shell selection by the hermit crab Paguristes tortugae Schmitt, 1933 from Anchieta Island (Brazil) was analyzed using the six most frequently occupied shell species in the field and taking into account the sexual condition of the individuals, the shell size and the shell species. The experiments were conducted under laboratory conditions and the shell species preference was estimated on the basis of the frequency that each species was chosen by the individuals. The preferred shell species and size were determined by regression analysis. The highest correlation coefficients were obtained for the relations between the hermit dimensions and shell dry weight. The ovigerous females preferred shells with larger internal volume: Leucozonia nassa (Gmelin, 1791) and Cerithium atratum (Born, 1778). In the experiment of shell size, males preferred heavier shells whereas females selected the shape characteristics of the shell, such as the aperture and the internal volume, which are probably related to the growth and offspring guarantee, respectively. In general, and independent of sex condition, P. tortugae showed significant selection among all shells utilized. The results suggest that shell selection by P. tortugae involves sexual and reproductive condition preferences.

Shell utilization pattern of the hermit crab Clibanarius vittatus (Crustacea, Anomura) in an estuary at São Vicente, State of São Paulo, Brazil

We evaluated the gastropod shell utilization pattern of the hermit crab Clibanarius vittatus (Bosc, 1802) at Pescadores Beach in São Vicente, State of São Paulo, Brazil. Specimens were collected monthly from May 2001 through April 2003, in the intertidal zone at low tide. The crabs were weighed and their carapace shield length measured. All gastropod shells were identified and had their shell biometric parameters (total length and aperture length) measured (mm) and weighed (g). A total of 2,344 hermit crabs (644 males, 1,594 females, 45 ovigerous females and 61 individuals in intersex), using 13 species of gastropod shells, were collected. Stramonita haemastoma (Linnaeus, 1767), Cymatium parthenopeum (Von Salis, 1793) and Achatina fulica (Bowdich, 1822) comprised over 98% of all the shells. Male and intersex crabs were significantly larger than the females. This size difference strongly influenced the shell utilization pattern, principally in A. fulica, which has the largest shell size, that was only used by males and intersexual individuals of C. vittatus. Cymatium parthenopeum was the only shell species that showed a high determinant coefficient in all the biometric correlations evaluated. The high abundance of S. haemastoma shells and a strong correlation between crab size and shell aperture length established by a significant determination coefficient, indicated that C. vittatus uses this species as the principal resource for shell occupation at Pescadores Beach.

Endogenous integration and welfare in complementary goods markets

This paper analyzes the strategic decision to integrate by firms that produce complementary products. Integration entails bundling pricing. We find out that integration is privately profitable for a high enough degree of product differentiation, that profits of the non-integrated firms decrease, and that consumer surplus need not necessarily increase when firms integrate despite the fact that prices diminish. Thus, integration of a system is welfare-improving for a high enough degree of product differentiation combined with a minimum demand advantage relative to the competing system. Overall, and from a number of extensions undertaken, we conclude that bundling need not be anti-competitive and that integration should be permitted only under some circumstances.

Capitalism, unemployment and the transition to the contemporary pattern of growth

A new model of unemployment based on an idea of Marx is presented and used to interpret the development of the British economy from the beginning of capitalism to the present. It is shown that unemployment may be created purposely by capitalists in order to weaken the bargaining position of the workers. This mechanism leads to complex temporal pattern of unemployment and can explain why wages took almost a century and a half to react to the growing capital to labour ratio that characterised early British capitalism.

Descentralisation, integration and polycentrism in Barcelona

In this study the employment subcentres of the Metropolitan Region of Barcelona are identified using different criteria. Once catalogued according to their nature,i.e. subcentres arising from integration and decentralisation, they are analysed to see whether their impact on population density depends on their origin. The results obtained confirm a greater impact of integrated subcentres in comparison with decentralised ones, amplified in turn by the fact that the former are further from the CBD and present a greater degree of self-containment in the labor market.

Financial integration, productivity and capital accumulation

Understanding the mechanism through which financial globalization affects economic performance is crucial for evaluating the costs and benefits of opening financial markets. This paper is a first attempt at disentangling the effects of financial integration on the two main determinants of economic performance: productivity (TFP) and investments. I provide empirical evidence from a sample of 93 countries observed between 1975 and 1999. The results suggest that financial integration has a positive direct effect on productivity, while it spurs capital accumulation only with some delay and indirectly, since capital follows the rise in productivity. I control for indirect effects of financial globalization through banking crises. Such episodes depress both investments and TFP, though they are triggered by financial integration only to a minor extent.

Why did London become the main money market? Monetary Policy, Arbitrage and European Money Market Integration in 18th century

How did the leading capital market start to attract international bullion? Why did London become the main money market? Monetary regulations, including the charges for minting money and the restrictions on bullion exchange, have played the key role in defining the direction of the flow of international bullion. Countries that abolished minting charges and permitted the free movement of bullion were able to attract international bullion, and countries that applied minting taxes suffered an outflow of bullion. In these cases monetary authorities tried to limit bullion movement through prohibitions on domestic bullion exchange at a free price, and tariffs and quantitative restrictions on bullion exports. The paper illustrates the logic of international monetary flow in the 18th century, using empirical evidence for England, France and Spain. The first section defines and measures monetary policy, and the second section introduces minting charges into the arbitrage equation in order to explain the logic of bullion flow between the pairs of nations England-France, England-Spain and France-Spain. The conclusion emphasises the importance of monetary policy in the creation of leading money markets.

The Experience of European Integration and the Potential for Integration in South America

The experience of the European Union is the most significant and far-reaching among all attempts at regional integration. It is, therefore, the most likely to provide some lessons for those world regions that are just beginning this complex process. In turn, the Common Market of the South (MERCOSUR) and the Andean Community (CAN) are among the regional integration projects that have reached the greatest level of formal accomplishment after the EU. MERCOSUR is a customs union that aspires to become a common market, while avowing the commitment to advance towards political integration. For its part, CAN is a customs union that has already developed supranational institutions such as a Commission, a Parliament and a Court of Justice. In both cases, however, words have progressively tended to wander far from deeds. One reason underlying this phenomenon may be a misunderstanding of the European experience with integration. In this article, we discuss the theories that have been developed to account for integration in Europe and may prove useful to understand integration elsewhere and put forward a set of lessons that could be drawn from the European experience. Subsequently, we introduce a description of the experience of integration in South America and reflect (critically) on how the theories and lessons drawn from the EU could be applied to this region –and beyond.

Studies on Trypanosoma rangeli Tejera, 1920: V - Developmental pattern in the alimentary canal of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the alimentary canal of Rhodnius prolixus, is described, with observation made in dissected guts from 6 hours to 45 days post-infection. No metacyclic-forms are produced in the digestive tract at any time, and transmission by the contaminative route must be considered atypical. Amastigotes appear to be an essential stage in the development of T. rangeli in the gut of R. prolixus. The epidemiological importance of the developmental pattern of T. rangeli in the vector´s gut is discussed, and its usefulness for aging infection is considered.

Creating the Gorizia-Goriska euroregion: an European cross-border administrative model for integrated socio-economic development in the upper adriatic. Crossborder co-operation as a tool for trans-national integration and conflict resolution

Contribució al Seminari: "Les Euroregions: Experiències i aprenatges per a l’Euroregió Pirineus-Mediterrània", 15-16 de desembre de 2005

Studies on Trypanosoma rangeli Tejera 1920: VI. Developmental pattern in the haemolymph of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the body cavity of Rhodnius prolixus is described. The metacyclic trypanosome is the product of successive division and transformation during the intra and extracellular development in the haemocoele. The significance of the early invasion of T. rangeli into the haemolymph is discussed. The epidemiological importance of the developmental pattern of T. rangeli in the vectors haemolymph and the host-response to the parasite are considered.

The changing pattern of pathology due to Schistosoma mansoni infection

A survey of the autopsy data on hepatosplenic schistosomiasis during periods, before and after the advent of new chemotherapeutic drugs, revealed that: a) the pathological presentation was the same for the two periods; b) the number of cases in the last five years is progressively decreasing; c) hepatosplenic disease due to schistosomiasis is becoming rare in young people. These data represent a change in the pattern of pathology in schistosomiasis, probably related to new chemotherapy.