Modelagem do produto interno bruto brasileiro utilizando modelos não lineares

O trabalho tem como objetivo aplicar uma modelagem não linear ao Produto Interno Bruto brasileiro. Para tanto foi testada a existência de não linearidade do processo gerador dos dados com a metodologia sugerida por Castle e Henry (2010). O teste consiste em verificar a persistência dos regressores não lineares no modelo linear irrestrito. A seguir a série é modelada a partir do modelo autoregressivo com limiar utilizando a abordagem geral para específico na seleção do modelo. O algoritmo Autometrics é utilizado para escolha do modelo não linear. Os resultados encontrados indicam que o Produto Interno Bruto do Brasil é melhor explicado por um modelo não linear com três mudanças de regime, que ocorrem no inicio dos anos 90, que, de fato, foi um período bastante volátil. Através da modelagem não linear existe o potencial para datação de ciclos, no entanto os resultados encontrados não foram suficientes para tal análise.

Auswirkungen des Klimawandels auf die klein- und großräumige genetische Populationsstruktur von Makrozoobenthos in Rhein, Main und Mosel

In den letzten Jahrzehnten wurde eine deutliche, anhaltende Veränderung des globalen Klimas beobachtet, die in Zukunft zu einer Erhöhung der durchschnittlichen Oberflächentemperatur, erhöhten Niederschlagsmengen und anderen gravierenden Umweltveränderungen führen wird (IPCC 2001). Der Klimawandel wird in Flüssen sowohl mehr Extremereignisse verursachen als auch das Abflussregime bisher schmelzwasserdominierter Flüsse zu grundwassergespeisten hin ändern; dies gilt insbesondere für den Rhein (MIDDELKOOP et al. 2001). Um die möglichen Auswirkungen dieser Veränderungen auf die genetische Populationsstruktur von Makrozoobenthosorganismen vorhersagen zu können, wurden in den grundwassergespeisten Flüssen Main und Mosel sowie im Rhein Entnahmestellen oberhalb und unterhalb von Staustufen beprobt, die durch kontrastierende Strömungsverhältnisse als Modell für die zu erwartenden Änderungen dienten. Als Untersuchungsobjekt wurden Dreissena polymorpha PALLAS 1771 sowie Dikerogammarus villosus SOWINSKI 1894 herangezogen. Sie zeichnen sich durch hohe Abundanzen aus, sind aber unterschiedlich u.a. hinsichtlich ihrer Besiedlungsstrategie und –historie. Bei beiden Spezies sind die phylogeographischen Hintergründe bekannt; daher wurde auch versucht, die Einwanderungsrouten in der Populationsstruktur nachzuweisen (phylogeographisches Szenario). Dies konkurrierte mit der möglichen Anpassung der Spezies an das Abflussregime des jeweiligen Flusses (Adaptations-Szenario). Die Populationen wurden molekulargenetisch mit Hilfe der AFLP-Methode („Amplified-Fragment Length Polymorphism“) untersucht. Die Ergebnisse zeigen, dass D. polymorpha deutlich durch die Abflussregimes der Flüsse (Schmelz- oder Grundwasserdominanz) beeinflusst wird. Die Allelfrequenzen in Populationen des Rheins sind von denen der beiden grundwassergespeisten Flüsse Main und Mosel deutlich unterscheidbar (Adaptations-Szenario). Jedoch ist kein Unterschied der genetischen Diversitäten zu beobachten; das ist auf die lange Adaptation an ihre jeweiligen Habitate durch die lange Besiedlungsdauer zurückzuführen. Dies ist auch der Grund, warum die Einwanderungsrouten anhand der Populationsstruktur nicht mehr nachzuweisen waren. Die kontrastierenden Strömungsverhältnisse um die Staustufen hatten ebenfalls keine konsistenten Auswirkungen auf die genetische Diversität der Populationen. Diese Ergebnisse zeigen eine hohe phänotypische Plastizität der Spezies und dadurch eine große Anpassungsfähigkeit an wechselnde Umweltbedingungen, die unter anderem für den großen Erfolg dieser Spezies verantwortlich ist. D. villosus wanderte erst vor Kurzem in das Untersuchungsgebiet ein; die Einwanderungsroute war anhand der genetischen Diversität nachvollziehbar (phylogeographisches Szenario); durch die kurze Besiedlungsdauer war eine Adaptation an die divergenten Abflussregime der Flüsse nicht zu erwarten und wurde auch nicht gefunden. Dagegen war ein deutlicher negativer Einfluss von starker Strömung auf die genetische Diversität nachweisbar. Die Ergebnisse weisen darauf hin, dass die zukünftigen Auswirkungen des Klimawandels auf die Strömungsgeschwindigkeit negative Konsequenzen auf die genetische Diversität von D. villosus haben werden, während D. polymorpha hier keine Auswirkungen erkennen lässt. Die Auswirkungen des veränderten Abflussregimes im Rhein sind für D. villosus mit den vorliegenden Daten aufgrund der kurzen Besiedlungsdauer nicht vorhersagbar; D. polymorpha wird durch die Veränderung des Rheins zu einem grundwassergespeisten Fluss zwar einen Wandel in der genetischen Struktur erfahren, aber auch hier keine Einbußen in der genetischen Diversität erleiden.

Foreign Direct Investment and Political Uncertainty

Recent developments in the general equilibrium theory of multinationals emphasize the importance of multilateral considerations. Yet, existing explanations and corresponding estimations of FDI patterns have largely limited political and institutional investment impediments to a bilateral framework. Through the application of spatial econometric techniques, I demonstrate that the presence of both domestic and regional political uncertainty generate real options effects that lead to the delay or redirection of foreign direct investment. The magnitude and direction of these effects is conditional upon the host country regime type and the predominant multinational integration strategies in the region. Comparing these results with FDI of U.S. origin, I find evidence for divergent investment behavior by U.S. multinationals during regime changes in partner countries. Additionally, I find no evidence that multinationals from developing countries are more likely to complete cross-border deals in environments characterized by greater political risk or political uncertainty.

The influence of the conservation status and changes in the rainfall regime on forest-savanna mosaic dynamics in Northern Brazilian Amazonia

Coupled carbon/climate models are predicting changes in Amazon carbon and water cycles for the near future, with conversion of forest into savanna-like vegetation. However, empirical data to support these models are still scarce for Amazon. Facing this scenario, we investigated whether conservation status and changes in rainfall regime have influenced the forest-savanna mosaic over 20 years, from 1986 to 2006, in a transitional area in Northern Amazonia. By applying a spectral linear mixture model to a Landsat-5-TM time series, we identified protected savanna enclaves within a strictly protected nature reserve (Maracá Ecological Station - MES) and non-protected forest islands at its outskirts and compared their areas among 1986/1994/2006. The protected savanna enclaves decreased 26% in the 20-years period at an average rate of 0.131 ha year-1, with a greater reduction rate observed during times of higher precipitation, whereas the non-protected forest islands remained stable throughout the period of study, balancing the encroachment of forests into the savanna during humid periods and savannization during reduced rainfall periods. Thus, keeping favorable climate conditions, the MES conservation status would continue to favor the forest encroachment upon savanna, while the non-protected outskirt areas would remain resilient to disturbance regimes. However, if the increases in the frequency of dry periods predicted by climate models for this region are confirmed, future changes in extension and directions of forest limits will be affected, disrupting ecological services as carbon storage and the maintenance of local biodiversity.

Regime dependent changes in global precipitation

Assessment of changes in precipitation (P) as a function of percentiles of surface temperature (T) and 500 hPa vertical velocity (ω) are presented, considering present-day simulations and observational estimates from the Global Precipitation Climatology Project (GPCP) combined with the European Centre for Medium-range Weather Forecasts Interim reanalysis (ERA Interim). There is a tendency for models to overestimate P in the warm, subsiding regimes compared to GPCP, in some cases by more than 100%, while many models underestimate P in the moderate temperature regimes. Considering climate change projections between 1980–1999 and 2080–2099, responses in P are characterised by dP/dT ≥ 4%/K over the coldest 10–20% of land points and over warm, ascending ocean points while P declines over the warmest, descending regimes (dP/dT ∼ − 4%/K for model ensemble means). The reduced Walker circulation limits this contrasting dP/dT response in the tropical wet and dry regimes only marginally. Around 70% of the global surface area exhibits a consistent sign for dP/dT in at least 6 out of a 7-member model ensemble when considering P composites in terms of dynamic regime.

Effects of handling regime and sex on changes in cortisol, thyroid hormones and body mass in fasting grey seal pups

Survival of seal pups may be affected by their ability to respond appropriately to stress. Chronic stress can adversely affect secretion of cortisol and thyroid hormones, which contribute to the control of fuel utilisation. Repeated handling could disrupt the endocrine response to stress and/or negatively impact upon mass changes during fasting. Here we investigated the effects of handling regime on cortisol and thyroid hormone levels, and body mass changes, in fasting male and female grey seal pups (Halichoerus grypus). Females had higher thyroid hormone levels than males throughout fasting and showed a reduction in cortisol midway through the fast that was not seen in males. This may reflect sex-specific fuel allocation or development. Neither handling frequency nor cumulative contact time affected plasma cortisol or thyroid hormone levels, the rate of increase in cortisol over the first five minutes of physical contact or the pattern of mass loss during fasting in either sex. The endocrine response to stress and the control of energy balance in grey seal pups appear to be robust to repeated, short periods of handling. Our results suggest that routine handling should have no additional impact on these animals than general disturbance caused by researchers moving around the colony.

Variabilidade do regime de monções sobre o Brasil: o clima presente e projeções para um cenário com 2xCO2 usando o modelo MIROC

Este trabalho investiga a variabilidade do Sistema de Monções da América do Sul (SMAS) sobre o Brasil com particular interesse na região do cerrado brasileiro. O início, final e total de precipitação durante as monções de verão são examinados utilizando estimativas de precipitação por satélite (pêntadas) do Global Precipitation Climatology Project (GPCP) entre 1979-2004. Analogamente, as características do regime de monção simuladas pelo modelo climático global acoplado MIROC (Model for interdisciplinary Research on Climate) do IPCC (Intergovernmental Panel for Climate Change) são examinadas em dois cenários distintos: o clima do século XX (1981-2000) e o clima em uma condição com o dobro da concentração atual de CO2 (2xCO2) na atmosfera (2061-2080). Mostra-se que a variabilidade espacial do início da monção de verão sobre o cerrado na simulação do clima do século XX pelo MIROC corresponde bem às observações. Além disso, há indicação de uma mudança das caudas da distribuição sazonal da precipitação no Cerrado para um cenário com 2xCO2, comparativamente com o clima presente. Este resultado sugere uma mudança na probabilidade de ocorrência de eventos extremos (secos ou úmidos) em um cenário com 2xCO2 sobre o cerrado, o que de acordo com o MIROC, indica uma maior exposição da região às conseqüências de possíveis mudanças climáticas resultantes do aumento de gases de efeito estufa.

Political Systems and the Perspective on Nursing Education during the Spanish Transition (from the Franco Regime to Democracy). A Contribution based on Nursing History

The aim of this study is to describe the changes in nursing education during the process prior to and after the establishment of democracy in Spain. It begins with the hypothesis that differences in social and political organization influenced the way the system of nursing education evolved, keeping it in line with neopositivistic schemes and exclusively technical approaches up until the advent of democracy. The evolution of a specific profile for nursing within the educational system has been shaped by the relationship between the systems of social and political organization in Spain. To examine the insertion of subjects such as the anthropology of healthcare into education programs for Spanish nursing, one must consider the cultural, intercultural and transcultural factors that are key to understanding the changes in nursing education that allowed for the adoption of a holistic approach in the curricula. Until the arrival of democracy in 1977, Spanish nursing education was solely technical in nature and the role of nurses was limited to the tasks and procedures defined by the bureaucratic thinking characteristic of the rational-technological paradigm. Consequently, during the long period prior to democracy, nursing in Spain was under the influence of neopositivistic and technical thinking, which had its effect on educational curricula. The addition of humanities and anthropology to the curricula, which facilitated a holistic approach, occurred once nursing became a field of study at the university level in 1977, a period that coincided with the beginnings of democracy in Spain.

Influence of hardness of the harder body on wear regime transition in a sliding pair of steels

In the unlubricated sliding wear of steels the mild-severe and severe-mild wear transitions have long been investigated. The effect of system inputs such as normal load, sliding speed, environment humidity and temperature, material properties, among others, on those transitions have also been studied. Although transitions seem to be caused by microstructural changes, surfaces oxidation and work-hardening, some questions remain regarding the way each aspect is involved. Since the early studies in sliding wear, it has usually been assumed that only the material properties of the softer body influence the wear behavior of contacting surfaces. For example, the Archard equation involves only the hardness of the softer body, without considering the hardness of the harder body. This work aims to discuss the importance of the harder body hardness in determining the wear regime operation. For this, pin-on-disk wear tests were carried out, in which the disk material was always harder than the pin material. Variations of the friction force and vertical displacement of the pin were registered during the tests. A material characterization before and after tests was conducted using stereoscopy and scanning electron microscopy (SEM) methods, in addition to mass loss, surface roughness and microhardness measurements. The wear results confirmed the occurrence of a mild-severe wear transition when the disk hardness was decreased. The disk hardness to pin hardness ratio (H(d)/H(p)) was used as a criterion to establish the nature of surface contact deformation and to determine the wear regime transition. A predominantly elastic or plastic contact, characterized by H(d)/H(p) values higher or lower than one, results in a mild or severe wear regime operation, respectively. (c) 2009 Elsevier B.V. All rights reserved.

Gas-surface interactions in the thermal and sub-thermal regime: A molecular dynamics study

Molecular dynamics simulations are used to study the interaction of low-energy Ar atoms with the Ni(001) surface, Angular scattering distributions, in and out of the plane of incidence, are investigated as a function of incident energy, angles of incidence, crystallographic orientation of the incident beam and surface temperature. The results show a clear transition to the structure scattering regime at around 2 eV. However, at lower energies, two sub-regimes are revealed by the simulations, Far energies up to 250 meV, scattering is mainly diffuse, and significant trapping on the surface is observed, At energies above this level, lobular patterns start to form and trapping decreases with the increase in energy, Generally, there is a weak temperature dependence, but variations in the angle of incidence and/or changes in the crystallographic direction, generate significant changes in the scattering patterns.

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.

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.

Modelling the influence of change in fire regime on the local distribution of a Mediterranean pyrophytic plant species (Cistus salviifolius) at its northern range limit

Aims: To assess the potential distribution of an obligate seeder and active pyrophyte, Cistus salviifolius, a vulnerable species in the Swiss Red List; to derive scenarios by changing the fire return interval; and to discuss the results from a conservation perspective. A more general aim is to assess the impact of fire as a natural factor influencing the vegetation of the southern slopes of the Alps. Locations: Alps, southern Switzerland. Methods: Presence-absence data to fit the model were obtained from the most recent field mapping of C. salviifolius. The quantitative environmental predictors used in this study include topographic, climatic and disturbance (fire) predictors. Models were fitted by logistic regression and evaluated by jackknife and bootstrap approaches. Changes in fire regime were simulated by increasing the time-return interval of fire (simulating longer periods without fire). Two scenarios were considered: no fire in the past 15 years; or in the past 35 years. Results: Rock cover, slope, topographic position, potential evapotranspiration and time elapsed since the last fire were selected in the final model. The Nagelkerke R-2 of the model for C. salviifolius was 0.57 and the Jackknife area under the curve evaluation was 0.89. The bootstrap evaluation revealed model robustness. By increasing the return interval of fire by either up to 15 years, or 35 years, the modelled C. salviifolius population declined by 30-40%, respectively. Main conclusions: Although fire plays a significant role, topography and rock cover appear to be the most important predictors, suggesting that the distribution of C. salviifolius in the southern Swiss Alps is closely related to the availability of supposedly competition-free sites, such as emerging bedrock, ridge locations or steep slopes. Fire is more likely to play a secondary role in allowing C. salviifolius to extend its occurrence temporarily, by increasing germination rates and reducing the competition from surrounding vegetation. To maintain a viable dormant seed bank for C. salviifolius, conservation managers should consider carrying out vegetation clearing and managing wild fire propagation to reduce competition and ensure sufficient recruitment for this species.

Predicting the future effectiveness of protected areas for bird conservation in Mediterranean ecosystems under climate change and novel fire regime scenarios

AimGlobal environmental changes challenge traditional conservation approaches based on the selection of static protected areas due to their limited ability to deal with the dynamic nature of driving forces relevant to biodiversity. The Natura 2000 network (N2000) constitutes a major milestone in biodiversity conservation in Europe, but the degree to which this static network will be able to reach its long-term conservation objectives raises concern. We assessed the changes in the effectiveness of N2000 in a Mediterranean ecosystem between 2000 and 2050 under different combinations of climate and land cover change scenarios. LocationCatalonia, Spain. MethodsPotential distribution changes of several terrestrial bird species of conservation interest included in the European Union's Birds Directive were predicted within an ensemble-forecasting framework that hierarchically integrated climate change and land cover change scenarios. Land cover changes were simulated using a spatially explicit fire-succession model that integrates fire management strategies and vegetation encroachment after the abandonment of cultivated areas as the main drivers of landscape dynamics in Mediterranean ecosystems. ResultsOur results suggest that the amount of suitable habitats for the target species will strongly decrease both inside and outside N2000. However, the effectiveness of N2000 is expected to increase in the next decades because the amount of suitable habitats is predicted to decrease less inside than outside this network. Main conclusionsSuch predictions shed light on the key role that the current N2000may play in the near future and emphasize the need for an integrative conservation perspective wherein agricultural, forest and fire management policies should be considered to effectively preserve key habitats for threatened birds in fire-prone, highly dynamic Mediterranean ecosystems. Results also show the importance of considering landscape dynamics and the synergies between different driving forces when assessing the long-term effectiveness of protected areas for biodiversity conservation.