MIGRAÇÃO E EVOLUÇÃO DA FRONTEIRA AGRÍCOLA

This work evaluates the relationship between the evolution of frontier areas and human migration in the Brazilian Amazon. To address this issue I propose a migratory transition model for evolving frontier areas. The model breaks the evolutionary process in four stages (pioneer, transitional, consolidated and urbanized) and describes the predominant migratory patterns in each phase. Dada to test the veracity of the proposed model were collected in a survey of sampled settlement areas in Roraima State, Brazil. Results demonstrate that the frontier evolution process influences migratory patterns, promoting changes in the selection process, origin areas, migratory trajectories, predominant migration type, and migration push factors. Key words: frontier evolution, human mobility, Brazilian Amazon, Roraima State.Este trabalho avalia a relação entre o processo evolutivo das fronteiras agrícolas e a migração na Amazônia brasileira. Eu proponho uma modelo de transição migratória para áreas de assentamento agrícola em processo de evolução. O modelo particiona o processo evolutivo dos assentamentos em quatro fases distintas (pioneira, transitória, consolidada e urbanizada) e tece uma série de considerações sobre os padrões migratórios predominantes em cada fase. Dados para testar a veracidade da proposta foram coletados a partir de um survey realizado em uma amostra de assentamentos do estado de Roraima. Os resultados demonstram que a evolução da fronteira agrícola tem um impacto decisivo nos padrões migratórios, provocando mudanças no processo de seleção de migrantes, áreas de origem, trajetórias migratórias, tipos predominantes de migração e fatores de atração. Palavras chaves: evolução da fronteira; mobilidade humana; amazônia brasileira, Roraima

MIGRAÇÃO, DESORGANIZAÇÃO SOCIAL E VIOLÊNCIA URBANA EM MINAS GERAIS

Dentre as diversas abordagens teóricas sobre os determinantes da violência urbana, destaca-se a desorganização social, que vincula a incidência criminal a processos de enfraquecimento de mecanismos de controle social. De acordo com esta perspectiva, intensas correntes imigratórias e a aglomeração de grandes massas populacionais em centros urbanos favorecem, potencialmente, a incidência criminal. Este estudo explora a relação entre as taxas de criminalidade violenta e as taxas de imigração, urbanização e tamanho populacional nos municípios mineiros no final da década de 1990, visando confrontar as idéias postuladas pela abordagem da desorganização social com a realidade mineira. Migration, social disorganization and urban violence in Minas Gerais Abstract Among the various theoretical interpretations of urban crime incidence the social disorganization approach deserves attention. This perspective associates crime to weakening social control mechanisms, suggesting that intense migratory flows and the agglomeration of large populations in urban areas potentially favor crime incidence. This study explores the relationship between violent crime rates and immigration, urbanization and total population rates among the municipalities of Minas Gerais State in the 1990s, in order to test the ideas postulated by the social disorganization perspective in Minas Gerais State

A FORMAÇÃO GEOHISTÓRICA DA ZONA DA MATA DE MINAS GERAIS

A Zona da Mata de Minas Gerais ocupa área correspondente a 6,09% da superfície do estado, com população de 2.029.168 habitantes, distribuída por 142 municípios, dos quais 70,23% com menos de 10.000 habitantes e baixo índice de urbanização. Atualmente, com uma economia equivalente a 8,37% do PIB total estadual e aproximadamente 11% da população do estado, a Zona da Mata apresenta baixa renda per capita e desempenho econômico muito aquém de suas potencialidades regionais. Some-se a isso o franco processo de estagnação econômica e rebaixamento do índice de qualidade de vida, exacerbando ainda mais os desequilíbrios espaciais intra-regionais. O presente trabalho debruça-se sobre a geohistória da Zona da Mata Mineira, buscando os determinantes históricos de sua condição socioeconômica desfavorável.The Zona da Mata region of Minas Gerais spreads throughout an area equivalent to 6,09% of the State, with a population of 2,029,168 inhabitants, distributed through 142 municipalities, of which 70,23% have less than 10.000 inhabitants and low levels of urbanization. Nowadays, the economy is equivalent to 8,37% of the State’s GDP and approximately 11% of the population. Zona da Mata displays low per capita income, and an economic performance that falls short to its great potentials. Besides, the ongoing economic stagnation together with the lowering of quality of life indexes have exacerbated intra-regional discrepancies. This work explores the geohitory of Zona da Mata Region of Minas Gerais, seeking for historical determinants of current socioeconomic conditions

Modeling body size evolution in Felidae under alternative phylogenetic hypotheses

The use of phylogenetic comparative methods in ecological research has advanced during the last twenty years, mainly due to accurate phylogenetic reconstructions based on molecular data and computational and statistical advances. We used phylogenetic correlograms and phylogenetic eigenvector regression (PVR) to model body size evolution in 35 worldwide Felidae (Mammalia, Carnivora) species using two alternative phylogenies and published body size data. The purpose was not to contrast the phylogenetic hypotheses but to evaluate how analyses of body size evolution patterns can be affected by the phylogeny used for comparative analyses (CA). Both phylogenies produced a strong phylogenetic pattern, with closely related species having similar body sizes and the similarity decreasing with increasing distances in time. The PVR explained 65% to 67% of body size variation and all Moran's I values for the PVR residuals were non-significant, indicating that both these models explained phylogenetic structures in trait variation. Even though our results did not suggest that any phylogeny can be used for CA with the same power, or that “good” phylogenies are unnecessary for the correct interpretation of the evolutionary dynamics of ecological, biogeographical, physiological or behavioral patterns, it does suggest that developments in CA can, and indeed should, proceed without waiting for perfect and fully resolved phylogenies

A review of techniques for spatial modeling in geographical, conservation and landscape genetics

Most evolutionary processes occur in a spatial context and several spatial analysis techniques have been employed in an exploratory context. However, the existence of autocorrelation can also perturb significance tests when data is analyzed using standard correlation and regression techniques on modeling genetic data as a function of explanatory variables. In this case, more complex models incorporating the effects of autocorrelation must be used. Here we review those models and compared their relative performances in a simple simulation, in which spatial patterns in allele frequencies were generated by a balance between random variation within populations and spatially-structured gene flow. Notwithstanding the somewhat idiosyncratic behavior of the techniques evaluated, it is clear that spatial autocorrelation affects Type I errors and that standard linear regression does not provide minimum variance estimators. Due to its flexibility, we stress that principal coordinate of neighbor matrices (PCNM) and related eigenvector mapping techniques seem to be the best approaches to spatial regression. In general, we hope that our review of commonly used spatial regression techniques in biology and ecology may aid population geneticists towards providing better explanations for population structures dealing with more complex regression problems throughout geographic space

High mobility group box 1 levels in large vessel vasculitis are not associated with disease activity but are influenced by age and statins

Introduction: Takayasu arteritis (TA) and giant cell arteritis (GCA) are large vessel vasculitides (LVV) that usually present as granulomatous inflammation in arterial walls. High mobility group box 1 (HMGB1) is a nuclear protein that acts as an alarmin when released by dying or activated cells. This study aims to evaluate whether serum HMGB1 can be used as a biomarker in LVV. Methods: Twenty-nine consecutive TA patients with 29 healthy controls (HC) were evaluated in a cross-sectional study. Eighteen consecutive GCA patients with 16 HC were evaluated at the onset of disease and some of them during follow-up. Serum HMGB1 levels were measured by enzyme-linked immunosorbent assay. Results: In GCA patients at disease onset mean serum HMGB1 levels did not differ from HC (5.74 +/- 4.19 ng/ml vs. 4.17 +/- 3.14 ng/ml; p = 0.230). No differences in HMGB1 levels were found between GCA patients with and without polymyalgia rheumatica (p = 0.167), ischemic manifestations (p = 0.873), systemic manifestations (p = 0.474) or relapsing disease (p = 0.608). During follow-up, no significant fluctuations on serum HMGB1 levels were observed from baseline to 3 months (n = 13) (p = 0.075), 12 months (n = 6) (p = 0.093) and at the first relapse (n = 4) (p = 0.202). Serum HMGB1 levels did not differ between TA patients and HC [1.19 (0.45-2.10) ng/ml vs. 1.46 (0.89-3.34) ng/ml; p = 0.181] and no difference was found between TA patients with active disease and in remission [1.31 (0.63-2.16) ng/ml vs. 0.75 (0.39-2.05) ng/ml; p = 0.281]. HMGB1 levels were significantly lower in 16 TA patients on statins compared with 13 patients without statins [0.59 (0.29-1.46) ng/ml vs. 1.93 (0.88-3.34) ng/ml; p = 0.019]. Age was independently associated with higher HMGB1 levels regardless of LVV or control status. Conclusions: Patients with TA and GCA present similar serum HMGB1 levels compared with HC. Serum HMGB1 is not useful to discriminate between active disease and remission. In TA, use of statins was associated with lower HMGB1 levels. HMGB1 is not a biomarker for LVV

Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil's bioenergy industry?

The authors gratefully thank the São Paulo Research Foundation (FAPESP) (grants # 2014/08632-9 # 2015/14122-6, # 2013/17581-6, # 2014/16612-8 and 2018/09845-7) for the scholarship granted while this research was carried out, and CNPq (grants # 402992/2013-0 and # 311661/2014-9) for the financial support of the present research. Anonymous reviewers are also thanked for their valuable criticisms and comments, which led to substantial improvements of this manuscript.Peer reviewedPostprintPostprin

Partitioning and mapping uncertainties in ensembles of forecasts of species turnover under climate change

Forecasts of species range shifts under climate change are fraught with uncertainties and ensemble forecasting may provide a framework to deal with such uncertainties. Here, a novel approach to partition the variance among modeled attributes, such as richness or turnover, and map sources of uncertainty in ensembles of forecasts is presented. We model the distributions of 3837 New World birds and project them into 2080. We then quantify and map the relative contribution of different sources of uncertainty from alternative methods for niche modeling, general circulation models (AOGCM), and emission scenarios. The greatest source of uncertainty in forecasts of species range shifts arises from using alternative methods for niche modeling, followed by AOGCM, and their interaction. Our results concur with previous studies that discovered that projections from alternative models can be extremely varied, but we provide a new analytical framework to examine uncertainties in models by quantifying their importance and mapping their patterns

Equilibrium of Global Amphibian Species Distributions with Climate

A common assumption in bioclimatic envelope modeling is that species distributions are in equilibrium with contemporary climate. A number of studies have measured departures from equilibrium in species distributions in particular regions, but such investigations were never carried out for a complete lineage across its entire distribution. We measure departures of equilibrium with contemporary climate for the distributions of the world amphibian species. Specifically, we fitted bioclimatic envelopes for 5544 species using three presence-only models. We then measured the proportion of the modeled envelope that is currently occupied by the species, as a metric of equilibrium of species distributions with climate. The assumption was that the greater the difference between modeled bioclimatic envelope and the occupied distribution, the greater the likelihood that species distribution would not be at equilibrium with contemporary climate. On average, amphibians occupied 30% to 57% of their potential distributions. Although patterns differed across regions, there were no significant differences among lineages. Species in the Neotropic, Afrotropics, Indo-Malay, and Palaearctic occupied a smaller proportion of their potential distributions than species in the Nearctic, Madagascar, and Australasia. We acknowledge that our models underestimate non equilibrium, and discuss potential reasons for the observed patterns. From a modeling perspective our results support the view that at global scale bioclimatic envelope models might perform similarly across lineages but differently across regions