Este artigo apresenta uma reflexão sobre a configuração dos mercados de proximidade. Em particular, observa a articulação que acontece entre troca e reciprocidade, a partir da análise das diversas formas de comercialização de produtos agropecuários originários da comunidade Lagoa dos Cavalos (município de Russas, sertão do Ceará). O objetivo é identificar se, apesar do avanço do capitalismo mercantil em certas regiões rurais, como no semiárido nordestino, os agricultores familiares continuam baseando suas estratégias de reprodução social em relações não-mercantis. A análise tomou como base teórica a reinterpretação de Granovetter para embeddedness (enraizamento da economia), a contribuição de Wilkinson sobre os mercados de proximidade e a teoria da reciprocidade de Temple. A análise adota a abordagem qualitativa e combina o uso de fontes testemunhais, documentais e bibliográficas. Na definição dos atores entrevistados, utilizou-se a amostragem não probabilística intencional. As conclusões apontam que os produtos são vendidos em mercados inscritos em circuitos coincidentes com a rede de proximidade, onde troca e reciprocidade coexistem e se articulam, complementando-se uma à outra.

The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51′ S and 33º 49′ W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil). The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE) and the other at norwest (NW). Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM – Deep Chlorophyll Maximum) and different times (day and night). According to PCA (Principal Component Analysis), the nutrients analyzed, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus) and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water). Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the “island effect” and not by upwelling.

The thermodynamics of the seasonal evolution of the Southwestern Tropical Atlantic Warm Pool (hereafter SWTAWP), which is delimited by the 28 °C isotherm, is investigated using the Regional Ocean Modeling System (ROMS). Results indicate that the net heat flux is responsible for the appearance and extinction of the SWTAWP. From March to May, the SWTAWP attains its maximum development and sometimes merges with equatorial warm waters towards the African continent, whose development follows the same period. Along the equator, the combination of oceanic terms (i.e., advection and diffusion) is important to promote the separation – when it occurs – of equatorial warm waters from southwestern tropical waters, which develops off the Brazilian coast. An analysis of the relative contribution of the temperature tendency terms of the mixed layer (ML) heat budget over the appearance, development and extinction of the SWTAWP is also done. The most important term for warming and cooling inside of the ML is the net heat flux at the sea surface. The ML is heated by the atmosphere between October and April, whereas the upper ocean cools down between May and September. The highest heat content values occur during the lower-temperature period (August to October), which is linked to the deepening of the ML during this time period. The horizontal advection along the equator is important, particularly at the eastern domain, which is influenced by the cold tongue. In this area, the vertical diffusive term is also significant; however, it presents values near zero outside the equator. These results contribute to a better understanding of the behavior of the heat budget within the tropical Atlantic, as previous studies over this region focused along the equator only.

The thermodynamics of the seasonal evolution of the Southwestern Tropical Atlantic Warm Pool (hereafter SWTAWP), which is delimited by the 28 °C isotherm, is investigated using the Regional Ocean Modeling System (ROMS). Results indicate that the net heat flux is responsible for the appearance and extinction of the SWTAWP. From March to May, the SWTAWP attains its maximum development and sometimes merges with equatorial warm waters towards the African continent, whose development follows the same period. Along the equator, the combination of oceanic terms (i.e., advection and diffusion) is important to promote the separation – when it occurs – of equatorial warm waters from southwestern tropical waters, which develops off the Brazilian coast. An analysis of the relative contribution of the temperature tendency terms of the mixed layer (ML) heat budget over the appearance, development and extinction of the SWTAWP is also done. The most important term for warming and cooling inside of the ML is the net heat flux at the sea surface. The ML is heated by the atmosphere between October and April, whereas the upper ocean cools down between May and September. The highest heat content values occur during the lower-temperature period (August to October), which is linked to the deepening of the ML during this time period. The horizontal advection along the equator is important, particularly at the eastern domain, which is influenced by the cold tongue. In this area, the vertical diffusive term is also significant; however, it presents values near zero outside the equator. These results contribute to a better understanding of the behavior of the heat budget within the tropical Atlantic, as previous studies over this region focused along the equator only.

Climate change will exacerbate the vulnerability of places and people around the world in the next decades, especially in less developed regions. In this paper, we investigate future scenarios of population vulnerability to climate change for the next 30 years in 66 regions of the state of Minas Gerais, Brazil. Based upon the Alkire & Foster Index, we integrate simulated and projected dimensions of population vulnerability into a Multidimensional Index, showing how scenarios of temperature change would affect each region’s relative vulnerability in the future. Results suggest that economic and health dimensions are the highest contributors to increases in temperature-related vulnerability, with the poorest and agribusiness regions being the most impacted in decades to come.

Arrebentar o cinema, como a onda o faz ao se abraçar numa só violência com a pedra. Filme, como superfície ondulante, deslimite-membrana de passagem entre as sonoridades e as visualidades. Uma imagem-ritornelo como procedimento que alimenta a terra nômade da nossa mecanosfera em catástrofe. As ondas, sua profundeza oceânica, que faz explodir o olho, cinema não mais um gesto ótico, mas sim tátil – handmade cinema. Mão que como onda se move sobre o celulóide, cinema que se pinta a cada gesto, a cada frame. Variações de uma máquina-ondas, imagem como campo vibrátil de experimentação, matéria metalizante entre meios. Onda que se precipita som, que se
precipita macha-cor, que se diz pequeno e grande ritornelo. Imagem-água-viva, No man’s land, No human’s land. Anônimo e anômalo, sem nome, só fazer variar As Ondas, Ondas que conectam o som da baleia com o do cometa, Ondas que se secam e transam com a areia, que se molecularizam e imperceptíveis se desfazem na poeira cósmica. Ondas que arruínam a casa do homem, desbordam e imanentes tudo o corroem. Cosmopolítica da imagem, ondaliferação na matéria plástica de expressão. Imagemonda, que devora a margem do mundo.

Background
The Amazon environment has been exposed in the last decades to radical changes that have been accompanied by a remarkable rise of both Plasmodium falciparum and Plasmodium vivax malaria. The malaria transmission process is highly influenced by factors such as spatial and temporal heterogeneities of the environment and individual-based characteristics of mosquitoes and humans populations. All these determinant factors can be simulated effectively trough agent-based models.

Methods
This paper presents a validated agent-based model of local-scale malaria transmission. The model reproduces the environment of a typical riverine village in the northern Peruvian Amazon, where the malaria transmission is highly seasonal and apparently associated with flooding of large areas caused by the neighbouring river. Agents representing humans, mosquitoes and the two species of Plasmodium (P. falciparum and P. vivax) are simulated in a spatially explicit representation of the environment around the village. The model environment includes: climate, people houses positions and elevation. A representation of changes in the mosquito breeding areas extension caused by the river flooding is also included in the simulation environment.

Results
A calibration process was carried out to reproduce the variations of the malaria monthly incidence over a period of 3 years. The calibrated model is also able to reproduce the spatial heterogeneities of local scale malaria transmission. A “what if” eradication strategy scenario is proposed: if the mosquito breeding sites are eliminated through mosquito larva habitat management in a buffer area extended at least 200 m around the village, the malaria transmission is eradicated from the village.

Conclusions
The use of agent-based models can reproduce effectively the spatiotemporal variations of the malaria transmission in a low endemicity environment dominated by river floodings like in the Amazon.

Climate change will exacerbate the vulnerability of places and people around the world in the next decades, especially in less developed regions. In this paper, we investigate future scenarios of population vulnerability to climate change for the next 30 years in 66 regions of the state of Minas Gerais, Brazil. Based upon the Alkire & Foster Index, we integrate simulated and projected dimensions of population vulnerability into a Multidimensional Index, showing how scenarios of temperature change would affect each region’s relative vulnerability in the future. Results suggest that economic and health dimensions are the highest contributors to increases in temperature-related vulnerability, with the poorest and agribusiness regions being the most impacted in decades to come.

The objective of this trial was to assess the methane emission rate, as well as the digestibility and ruminal fermentation parameters in animals fed Urochloa brizantha hay harvested at different stages of growth. Six Nellore rumen-cannulated steers (402.0 ± 51.62 kg) were assigned to a replicated 3×3 Latin square (18 experimental units). Treatments differed according to three growth stages of the forage: 15 – hay with 15 days of growth, 45 – hay with 45 days of growth and 90 – hay with 90 days of growth. Each experimental period lasted 21 days. From the 8^th day, feces were sampled during 5 days to determine apparent total digestibility of dry matter and its fractions. Beginning on the 13^th day and running for 7 days, methane production was evaluated using the sulfur hexafluoride (SF₆) tracer technique. On the 20^th day, ruminal fluid was sampled prior to and after 2, 4, 6, 8 and 10 hours post-morning feeding for evaluating pH, ammonia-N and short-chain fatty acids (SCFA). As the stage of forage growth for harvesting advanced in days, the digestibility coefficient of crude protein decreased and non-fibrous carbohydrate values increased. Methane production was affected not only by the stage of forage growth, but also by quality of its conservation after harvesting. There were significant differences among treatments when methane was expressed in g kg^-1 DMI, g kg^-1 OMI, % GE and % DE, with non-linear effect. The stage of forage growth did not influence ruminal pH, total concentration or molar proportion of SCFA, but decreased NH₃-N concentration.

O método de irrigação do arroz condiciona manejos diferenciados do solo e da cultura, proporcionando potenciais distintos de emissão de metano (CH4) e óxido nitroso (N2O) do solo durante o período de cultivo do arroz e, possivelmente, também durante a entressafra (outono/inverno). O objetivo desse trabalho foi avaliar as emissões
anuais de CH4 e de N2 O de solo de terras baixas cultivado com arroz irrigado por inundação e por aspersão, comparando-as com as emissões de mesmo solo sem histórico recente de cultivo (área natural). O estudo foi realizado no período de novembro de 2011 a novembro de 2012, em Planossolo Háplico, no município de Capão do
Leão, RS. Avaliaram-se os seguintes tratamentos: área cultivada com arroz irrigado por inundação na safra 2011/2012 e mantida em pousio com ressemeadura de azevém no outono/inverno de 2012 (Inundação); área cultivada com arroz irrigado por aspersão na safra 2011/2012 e com nabo forrageiro em sistema plantio direto durante o outono/inverno de 2012 (Aspersão); e área natural adjacente às demais (Área natural), com mesmo solo e sem histórico de cultivo nos últimos 20 anos. Periodicamente, realizaram-se coletas de amostras de ar, pelo
método da câmara estática fechada. A adoção do método de irrigação por aspersão para o arroz promove a mitigação das emissões de metano do solo em terras baixas do Rio Grande do Sul, relativamente à irrigação por inundação, porém potencializa as emissões de óxido nitroso nos períodos de safra (primavera/verão) e de entressafra
(outono/inverno). O potencial de aquecimento global parcial de área irrigada por inundação decorre basicamente da emissão de metano, sendo superior ao de área irrigada por aspersão durante o período de cultivo do arroz (safra de primavera/verão). Na entressafra, a área sob irrigação por aspersão apresenta maior potencial de aquecimento
global parcial (composto exclusivamente por N2O) que a área irrigada por inundação. Os dois sistemas de irrigação (aspersão e inundação), quando comparados com área natural sem histórico de cultivo recente, apresentam menores valores de potencial de aquecimento global parcial nos períodos de safra e de entressafra.

Em áreas de produção de arroz irrigado, a época e as operações de preparo do solo determinam potenciais distintos de incorporação de carbono (C) e nitrogênio (N) ao solo e de emissão de gases de efeito estufa (GEE). Realizou-se um trabalho para avaliar o efeito do manejo do solo e da cobertura vegetal sobre as emissões de metano (CH4) e óxido nitroso (N2O), durante o outono/inverno, de Planossolo cultivado com arroz irrigado. O estudo foi realizado de abril a outubro de 2013, em Capão do Leão, RS. Avaliaram-se três sistemas de preparo do solo: preparo antecipado de outono, preparo convencional de primavera e preparo com rolo-faca no outono. As coletas dos gases foram realizadas semanalmente, utilizando-se o método da câmara estática fechada. A época e as operações de preparo do
solo proporcionaram potenciais distintos de emissão de metano e óxido nitroso em Planossolo durante o outono/inverno. As emissões totais de metano foram maiores na área preparada com rolo-faca, seguida daquela com preparo convencional e antecipado. Também as emissões totais de óxido nitroso foram maiores para o preparo
com rolo-faca, seguida da área com preparo antecipado; o preparo convencional não proporcionou emissões de óxido nitroso. Em todos os sistemas de preparo, o metano foi o principal componente do potencial de aquecimento global parcial (PAGp) de Planossolo cultivado com arroz irrigado durante o período de entressafra.

Nine surface water surveys were performed in the Formoso estuary (Brazil) during 2012-2013 mainly in summer and winter periods and during spring tide. Temporal variations of temperature, salinity, phosphate, silicate, total alkalinity, dissolved inorganic carbon, partial pressure of CO2 (pCO2) and water-air CO2 fluxes were analyzed. Low rates of water-air CO2 fluxes (4.7 ± 8.0 mmol C m-2 d-1) were estimated despite the different climate conditions. pCO2 values ranged from 190 to 988 matm. These values are lower than those observed in other tropical estuaries. CO2 fluxes presented in this study contribute to the characterization of humid tropical estuarine systems, thus filling an important geographical information gap.