Dispersal strategies, few dominating or many coexisting: the effect of environmental spatial structure and multiple sources of mortality.

Interspecific competition, life history traits, environmental heterogeneity and spatial structure as well as disturbance are known to impact the successful dispersal strategies in metacommunities. However, studies on the direction of impact of those factors on dispersal have yielded contradictory results and often considered only few competing dispersal strategies at the same time. We used a unifying modeling approach to contrast the combined effects of species traits (adult survival, specialization), environmental heterogeneity and structure (spatial autocorrelation, habitat availability) and disturbance on the selected, maintained and coexisting dispersal strategies in heterogeneous metacommunities. Using a negative exponential dispersal kernel, we allowed for variation of both species dispersal distance and dispersal rate. We showed that strong disturbance promotes species with high dispersal abilities, while low local adult survival and habitat availability select against them. Spatial autocorrelation favors species with higher dispersal ability when adult survival and disturbance rate are low, and selects against them in the opposite situation. Interestingly, several dispersal strategies coexist when disturbance and adult survival act in opposition, as for example when strong disturbance regime favors species with high dispersal abilities while low adult survival selects species with low dispersal. Our results unify apparently contradictory previous results and demonstrate that spatial structure, disturbance and adult survival determine the success and diversity of coexisting dispersal strategies in competing metacommunities.

Entrepreneurship, organization and economic performance among Spanish firms, 1930-1975. The case of the motor industry

Before the Civil War (1936-1939), Spain had seen the emergence offirms of complex organizational forms. However, the conflict andthe postwar years changed this pattern. The argument put forwardin this paper is based on historical experience, the efforts willbe addressed to explain the development of Spanish entrepreneurshipduring the second half of the twentieth century. To illustrate thechange in entrepreneurship and organizational patterns among theSpanish firms during the Francoist regime we will turn to the caseof the motor vehicle industry.

Setting the rules of the game: The choice of electoral systems in advanced democracies

The origins of electoral systems have received scant attention in the literature. Looking at the history of electoral rules in the advanced world in the last century, this paper shows that the existing wide variation in electoral rules across nations can be traced to the strategic decisions that the current ruling parties, anticipating the coordinating consequences of different electoral regimes, make to maximize their representation according to the following conditions. On the one hand, as long as the electoral arena does not change substantially and the current electoral regime serves the ruling parties well, the latter have no incentives to modify the electoral regime. On the other hand, as soon as the electoral arena changes (due to the entry of new voters or a change in their preferences), the ruling parties will entertain changing the electoral system, depending on two main conditions: the emergence of new parties and the coordinating capacities of the old ruling parties. Accordingly, if the new parties are strong, the old parties shift from plurality/majority rules to proportional representation (PR) only if the latter are locked into a 'non-Duvergerian' equilibrium; i.e. if no old party enjoys a dominant position (the case of most small European states)--conversely, they do not if a Duvergerian equilibrium exists (the case of Great Britain). Similarly, whenever the new entrants are weak, a non-PR system is maintained, regardless of the structure of the old party system (the case of the USA). The paper discusses as well the role of trade and ethnic and religious heterogeneity in the adoption of PR rules.

A 15-year post evaluation of the fire effects on ant community in an area of Amazonian forest

Fire represents an important disturbance to ant communities in areas of fire regime. Otherwise, little is known about the effects of fire on ant communities in areas of non-fire regimes, such as in the Amazonian region. We evaluated the long-term effect of fire on ant species richness in a rain forest (Bacaba Plateau) burned 15-years ago and compare our data with the data of primary unburned forest. A total of 85 ant species distributed in 21 genera and 14 tribes were collected; among them, 72 and 44 species were found on the litter and vegetation, respectively. The fire damaged forest studied supports an intermediate richness of ants when compared to a primary unburned rain forest in the same region. A comparative analysis of ant species richness showed that the Bacaba Plateau presented a different ant fauna when compared with the primary unburned forests, suggesting that fire can alter ant species composition. Although, our results cannot be conclusive on the effects of fire on ant community, they represent a pioneer data on human induced fire in tropical rain forests.

Molecular epidemiology and evolution of HIV-1 in Portugal and portuguese speaking african countries

The aims of this thesis were to better characterize HIV-1 diversity in Portugal, Angola, Mozambique and Cape Verde and to investigate the origin and epidemiological history of HIV-1 in these countries. The impact of these issues in diagnosis, disease progression and susceptibility to ARV therapy was also investigated. Finally, the nature, dynamics and prevalence of transmitted drug resistance (TDR) was determined in untreated HIV-1 infected patients. In Angola, practically all HIV-1 genetic forms were found, including almost all subtypes, untypable (U) strains, CRFs and URFs. Recombinants (first and second generation) were present in 47.1% of the patients. HIV/AIDS epidemic in Angola probably started in 1961, the major cause being the independence war, subsequently spreading to Portugal. In Maputo, 81% of the patients were infected with subtype C viruses. Subtype G, U and recombinants such as CRF37_cpx, were also present. The results suggest that HIV-1 epidemic in Mozambique is evolving rapidly in genetic complexity. In Cape Verde, where HIV-1 and HIV-2 co-circulate, subtype G is the prevailed subtype. Subtypes B, C, F1, U, CRF02_AG and other recombinant strains were also found. HIV-2 isolates belonged to group A, some being closely related to the original ROD isolate. In all three countries numerous new polymorphisms were identified in the RT and PR of HIV-1 viruses. Mutations conferring resistance to the NRTIs or NNRTIs were found in isolates from 2 (2%) patients from Angola, 4 (6%) from Mozambique and 3 (12%) from Cape Verde. None of the isolates containing TDR mutations would be fully sensitive to the standard first-line therapeutic regimens used in these countries. Close surveillance in treated and untreated populations will be crucial to prevent further transmission of drug resistant strains and maximize the efficacy of ARV therapy. In Portugal, investigation of a seronegative case infection with rapid progression to AIDS and death revealed that the patient was infected with a CRF14_BG-like R5-tropic strain selectively transmitted by his seropositive sexual partner. The results suggest a massive infection with a highly aggressive CRF14_BG like strain and/or the presence of an unidentified immunological problem that prevented the formation of HIV-1-specific antibodies. Near full-length genomic sequences obtained from three unrelated patients enabled the first molecular and phylogenomic characterization of CRF14_BG from Portugal; all sequences were strongly related with CRF14_BG Spanish isolates. The mean date of origin of CRF14_BG was estimated to be 1992. We propose that CRF14_BG emerged in Portugal in the early 1990s, spread to Spain in late 1990s as a consequence of IDUs migration and then to the rest of Europe. Most CRF14_BG strains were predicted to use CXCR4 and were associated with rapid CD4 depletion and disease progression. Finally, we provide evidence suggesting that the X4 tropism of CRF14_BG may have resulted from convergent evolution of the V3 loop possibly driven by an effective escape from neutralizing antibody response.

Money and prices in models of bounded rationality in high inflation economies

This paper studies the short run correlation of inflation and money growth. We study whether a model of learning can do better than a model of rational expectations, we focus our study on countries of high inflation. We take the money process as an exogenous variable, estimated from the data through a switching regime process. We findthat the rational expectations model and the model of learning both offer very good explanations for the joint behavior of money and prices.

Making land-use fit to planning goals. Weaknesses and opportunities within the Swiss land management regime

In Switzerland, the issue of land consumption has made it to the front of the political agenda in recent years. Studies conducted on a national level have concluded that there is an excess of land zoned for construction (ARE, 2008), which is seen as contributing to urban sprawl. This situation is looked upon as a failure of the Federal Law on Spatial Planning (LAT, 1979) and there is a political push to change it in order to reinforce zoning regulations. In this article, we look on the issue from a different angle. While there may be large quantities of land zoned for construction, in many urban areas land actually available for development is scarce. Building on the idea that planning's efficiency is linked to its capacity of influencing actual land-use, we focus on how this situation can be dealt with within the current Swiss institutional context.

Malthusian dynamism and the rise of Europe: Make war, not love

This paper argues that Malthusian regimes are capable of sustained changes in per capita incomes. Shifting mortality and fertility schedules can lead to different steady-state income levels, with long periods of growth during the transition. Europe checked the downward pressure on wages through late marriage, which reduced fertility, and a mortality regime that combined high death rates with high incomes. We argue that both emerged as a result of the Black Death.

Manipulation of earnings reports in Spain - some evidence

Accounting regulation is a highly topical issue for listed companies in Europe. From 1 January 2005 all companies listed in the EU member states are required to produce financial reports compliant with international accounting standards. Financial reports will be comparable with each other only if full compliance with the international standards can be ensured. Historically, however, an enduring weakness of the international standard-setting regime has been its inability to enforce compliance with its standards. There is a danger that implementation and compliance will be variable across the adopting countries, and that deeply ingrained national reporting practices will persist. The purpose of this paper is to examine some distinctive elements of Spanish financial reporting practices. Spanish financial reporting by major companies demonstrates a tendency towards quite overt manipulation of the earnings figures. The research reported in the paper firstly identifies four common earnings manipulation practices, and then proceeds to examine their incidence in the financial statements of the IBEX-35 companies over a three year period.

The three horsemen of riches: Plague, war and urbanization in early modern Europe

How did Europe escape the "Iron Law of Wages?" We construct a simple Malthusian model withtwo sectors and multiple steady states, and use it to explain why European per capita incomes andurbanization rates increased during the period 1350-1700. Productivity growth can only explain a smallfraction of the rise in output per capita. Population dynamics changes of the birth and death schedules were far more important determinants of steady states. We show how a major shock to population cantrigger a transition to a new steady state with higher per-capita income. The Black Death was such ashock, raising wages substantially. Because of Engel's Law, demand for urban products increased, andurban centers grew in size. European cities were unhealthy, and rising urbanization pushed up aggregatedeath rates. This effect was reinforced by diseases spread through war, financed by higher tax revenues.In addition, rising trade also spread diseases. In this way higher wages themselves reduced populationpressure. We show in a calibration exercise that our model can account for the sustained rise in Europeanurbanization as well as permanently higher per capita incomes in 1700, without technological change.Wars contributed importantly to the "Rise of Europe", even if they had negative short-run effects. We thustrace Europe s precocious rise to economic riches to interactions of the plague shock with the belligerentpolitical environment and the nature of cities.

Effects of convection on the removal of the multiplicity of stable states in one-dimensional vertical models

Here I develop a model of a radiative-convective atmosphere with both radiative and convective schemes highly simplified. The atmospheric absorption of radiation at selective wavelengths makes use of constant mass absorption coefficients in finite width spectral bands. The convective regime is introduced by using a prescribed lapse rate in the troposphere. The main novelty of the radiative-convective model developed here is that it is solved without using any angular approximation for the radiation field. The solution obtained in the purely radiation mode (i. e. with convection ignored) leads to multiple equilibria of stable states, being very similar to some results recently found in simple models of planetary atmospheres. However, the introduction of convective processes removes the multiple equilibria of stable states. This shows the importance of taking convective processes into account even for qualitative analyses of planetary atmosphere

VLA multifrequency observations of RSCVn binaries

We present multiepoch Very Large Array (VLA) observations at 1.4 GHz, 4.9 GHz, 8.5 GHz and 14.9 GHz for a sample of eight RS CVn binary systems. Circular polarization measurements of these systems are also reported. Most of the fluxes observed are consistent with incoherent emission from mildly relativistic electrons. Several systems show an increase of the degree of circular polarization with increasing frequency in the optically thin regime, in conflict with predictions by gyrosynchrotron models. We observed a reversal in the sense of circular polarization with increasing frequency in three non-eclipsing systems: EI Eri, DM Uma and HD 8358. We find clear evidence for coherent plasma emission at 1.4 GHz in the quiescent spectrum of HD 8358 during the helicity reversal. The degrees of polarization of the other two systems could also be accounted for by a coherent emission process. The observations of ER Vul revealed two U-shaped flux spectra at the highest frequencies. The U-shape of the spectra may be accounted for by an optically thin gyrosynchrotron source for the low frequency part whereas the high frequency part is dominated by a thermal emission component.

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

In the general discussion on the Variscan evolution of central Europe the pre-Mesozoic basement of the Alps is, in many cases, only included with hesitation. Relatively well-preserved from Alpine metamorphism, the Alpine External massifs can serve as an excellent example of evolution of the Variscan basement, including the earliest Gondwana-derived microcontinents with Cadomian relics. Testifying to the evolution at the Gondwana margin, at least since the Cambrian, such pieces took part in the birth of the Rheic Ocean. After the separation of Avalonia, the remaining Gondwana border was continuously transformed through crustal extension with contemporaneous separation of continental blocks composing future Pangea, but the opening of Palaeotethys had only a reduced significance since the Devonian. The Variscan evolution in the External domain is characterised by an early HP-evolution with subsequent granulitic decompression melts. During Visean crustal shortening, the areas of future formation of migmatites and intrusion of monzodioritic magmas in a general strike-slip regime, were probably in a lower plate situation, whereas the so called monometamorphic areas may have been in an upper plate position of the nappe pile. During the Latest Carboniferous, the emplacement of the youngest granites was associated with the strike-slip faulting and crustal extension at lower crustal levels, whereas, at the surface, detrital sediments accumulated in intramontaneous transtensional basins on a strongly eroded surface. To cite this article: J.R von Raumer et al., C. R. Geoscience 341 (2009). (C) 2008 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

The European sugar regime new legislation and wto rules

[cat] El 20 de febrer de 2006 es va aprovar el Reglament núm. 318/2006 del Consell que reforma l'Organització Comuna de Mercats del sucre. L'article analitza els canvis introduïts en el nou règim europeu del sucre i valora la seva adequació a les normes i demandes internacionals de liberalització del comerç agrícola. Es conclou que la reforma ha estat el mínim necessari per fer front als reptes internacionals: la recent resolució de l'Òrgan de Solució de Diferències de l'Organització Mundial del Comerç i les demandes de liberalització plantejades en el marc de la Ronda de Doha.

Phylogenetic relatedness and proboscis length contribute to structuring bumblebee communities in the extremes of abiotic and biotic gradients

Aim To improve our understanding of how biological communities assemble, we investigated changes in bumblebee communities in space along an elevation gradient. We assessed how much deterministic abiotic and biotic factors shape community assembly. We focused on proboscis length (influencing the species' dietary regime) and phylogenetic relatedness to investigate if competition and environmental filtering occur in more and less productive climates, respectively. Location Western Swiss Alps. Methods We recorded bumblebee species in 149 plots along a 1800-m wide elevation gradient. We contrasted two major clades of bumblebees, a short-tongued and a long-tongued clade. We calculated the phylogenetic and proboscis-length diversity of the bumblebee communities and compared these observed data with a random distribution to detect clustering likely to be caused by environmental filtering or overdispersion likely to be caused by competition. We compared the prevalence of clustered and overdispersed communities along the gradients of plant species richness (biotic) and temperature (abiotic). Results Under colder conditions, where plant species richness is lower and floral resources are scarcer, the clade with shorter proboscides prevails over the clade with longer proboscides, and communities are functionally and phylogenetic clustered. Under warmer conditions, we found phylogenetic but not functional overdispersion in communities. Main conclusions We show for the first time a strong correlation between phylogenetic relatedness, proboscis length and species distribution along temperature and plant richness gradients shaping bumblebee communities. The low temperatures and low levels of plant species richness limit the dispersal of the species from the long-tongued clade, which have more specialized diets, into high-elevation areas. Competition under warmer conditions may produce communities composed of less closely related species that share distinct ecological preferences. Our empirical results corroborate theoretical expectation as well as experiments on the prevalence of deterministic processes in the most severe and most productive parts of environmental gradients.