In time series forecasting exercises it has been usual to suppose that the error series generated by the forecasters have a white noise behavior. However, it is possible that such supposition is violated in practice due to model misspecification or disturbances of the phenomenon not captured by the predictive models. It may lead to statistically biased and/or inefficient predictors. The present paper introduces an approach to correct predetermined forecasters by recursively modeling their remaining residuals. Two formalisms are used to illustrate the recursive approach: the well-known (linear) autoregressive integrated moving average (ARIMA) and the (non-linear) Artificial Neural Network (ANN). These models are recursively adjusted to the remaining residuals of a given forecaster until a white noise behavior is achieved. Applications involving ARIMA and ANN forecasters for Dow Jones Industrial Average Index, S&P500 Index, Google Stock Value, Nasdaq Index, Wolf׳s Sunspot, and Canadian Lynx data series indicate the usefulness of the proposed framework.

O presente estudo teve como objetivo avaliar a qualidade de vida de idosos com Diabetes Mellitus do tipo 2 acompanhados pelos profissionais da atenção básica. Trata-se de um estudo descritivo e transversal, de abordagem quantitativa, realizado no ano de 2011 com 68 idosos diabéticos cadastrados nas unidades de saúde do município de Cajazeiras – Paraíba, por meio da aplicação de um instrumento com variáveis sociodemográficas e outro para avaliar a qualidade de vida – Problems Areas in Diabetes Scale (B-PAID), versões brasileiras. Os resultados apontaram que, de maneira geral, o diabetes exerce impacto significativo na vida dos idosos mais jovens (com média de 68,84 anos), do sexo feminino (75%), com grau de escolaridade menor (60,3%) e menor tempo de diagnóstico da doença (média de 6,62 anos). Conclui-se que, embora a maioria dos participantes do estudo tenha manifestado um bom padrão de qualidade de vida relacionado à saúde, ter diabetes traz especificidades que variam de indivíduo para indivíduo, caracterizando o fenômeno como singular. Pode-se ainda conhecer as dimensões mais negativas causadas pela diabetes, possibilitando assim o planejamento de ações de promoção da saúde e prevenção voltadas a este grupo com vistas à melhoria da qualidade de vida.

The impact of El Niño–Southern Oscillation (ENSO) on the South Atlantic subtropical dipole mode (SASD) is investigated using both observations and model simulations. The SASD is the dominant mode of coupled ocean–atmosphere variability in the South Atlantic. This study focuses on austral summer, when both ENSO and SASD peak. It is shown that negative SASD events are associated with central Pacific El Niño events by triggering the Pacific–South American wave train (PSA). The latter resembles the third leading mode of atmospheric variability in the Southern Hemisphere (PSA2) and causes a weakening and meridional shift of the South Atlantic subtropical high, which then generates the negative SASD events. On the other hand, a strengthening of the South Atlantic subtropical high related to central La Niña teleconnections causes positive SASD events. The results herein show that the PSA2, triggered by central Pacific ENSO events, connects the tropical Pacific to the Atlantic. This connection is absent from eastern Pacific ENSO events, which appear to initiate the second leading mode of atmospheric variability in the Southern Hemisphere (PSA1). It is for this reason that previous studies have found weak correlations between ENSO and SASD. These findings can improve the climate prediction of southeastern South America and southern Africa since these regions are affected by sea surface temperature anomalies of both the Pacific and Atlantic Oceans.

Mercury (Hg) contamination is an issue of concern in the Amazon region due to potential health effects associated with Hg exposure in artisanal gold mining areas. The study presents a human health risk assessment associated with Hg vapor inhalation and MeHg-contaminated fish ingestion, as well as Hg determination in urine, blood, and hair, of human populations (about 325 miners and 321 non-miners) from two gold mining areas in the Brazilian Amazon (São Chico and Creporizinho, Pará State). In São Chico and Creporizinho, 73 fish specimens of 13 freshwater species, and 161 specimens of 11 species, were collected for total Hg determination, respectively. The hazard quotient (HQ) is a risk indicator which defines the ratio of the exposure level and the toxicological reference dose and was applied to determine the threat of MeHg exposure. The mean Hg concentrations in fish from São Chico and Creporizinho were 0.83 ± 0.43 and 0.36 ± 0.33 μg/g, respectively. More than 60 and 22 % of fish collected in São Chico and Creporizinho, respectively, were above the Hg limit (0.5 μg/g) recommended by WHO for human consumption. For all sampling sites, HQ resulted from 1.5 to 28.5, except for the reference area. In Creporizinho, the values of HQ are close to 2 for most sites, whereas in São Chico, there is a hot spot of MeHg contamination in fish (A2—São Chico Reservoir) with the highest risk level (HQ = 28) associated with its human consumption. Mean Hg concentrations in urine, blood, and hair samples indicated that the miners group (in São Chico: urine = 17.37 μg/L; blood = 27.74 μg/L; hair = 4.50 μg/g and in Creporizinho: urine = 13.75 μg/L; blood = 25.23 μg/L; hair: 4.58 μg/g) was more exposed to mercury compared to non-miners (in São Chico: urine = 5.73 μg/L; blood = 16.50 μg/L; hair = 3.16 μg/g and in Creporizinho: urine = 3.91 μg/L; blood = 21.04 μg/L, hair = 1.88 μg/g). These high Hg levels (found not only in miners but also in non-miners who live near the mining areas) are likely to be related to a potential hazard due to exposure to both Hg vapor by inhalation and to MeHg-contaminated fish ingestion.

Entre os pinus tropicais, Pinus caribaea var. hondurensis é uma variedade
natural, oriunda de região com clima tropical na América Central. A espécie se aclimatou
bem em várias partes do mundo, em regiões com alta pluviosidade e temperaturas elevadas.
Embora não tolere geadas severas, pode ser plantada em partes da região Sul do Brasil
onde o clima é mais quente e a frequência de geadas é menor e é indicado para plantio em
boa parte do Brasil, em mais de 3,5 milhões de km2. Essa é uma variedade que apresenta
alto rendimento em madeira de boa qualidade, além de possibilitar a exploração da resina.
Neste trabalho, são apresentadas as regiões no Brasil que apresentam potencial para
cultivo dessa variedade em regime de silvicultura intensiva, tomando como base sua
região de origem no mundo. São indicadas para plantio comercial as zonas com os menores
riscos de geada nos estados da região Sul, no Estado de São Paulo e nas demais regiões
que oferecem condições climáticas favoráveis, principalmente de disponibilidade hídrica
para o desenvolvimento dessa variedade de pinus.

Previous numerical simulations have suggested that the area adjacent to Itaipu Lake in Southern Brazil is significantly affecting the local thermal regime through development of a lake breeze. This has led to concerns that soybean growth and development, and consequently yield, has been affected by the creation of the artificial lake in this important agricultural region, but a systematic climatological study of the thermal effects of Itaipu Lake has not been conducted. The objectives of this study were to assess the spatial pattern of minimum and maximum air temperatures in a 10-km-wide area adjacent to Itaipu Lake as affected by distance from the water. Measurements were conducted over 3 years in seven transects along the shore of Itaipu Lake, with five weather stations placed in each transect. Phenological observations in soybean fields surrounding the weather stations were also conducted. Generalized additive models for location, scale, and shape (GAMLSS) analysis indicated no difference in the temperature time series as distance from water increased. Semivariograms showed that the random components in the air temperature were predominant and that there was no spatial structure to the signal. Wind direction measured over the three growing seasons demonstrated that, on average, the development of a lake breeze is limited to a few locations and a few hours of the day, supporting the temporal and spatial analysis. Phenological observations did not show differences in the timing of critical soybean stages. We suggest that the concerns that soybean development is potentially affected by the presence of Itaipu Lake are not supported by the thermal environment observed.

While a number of papers have shown that subway systems have an impact on the air quality through the release of particulate matters, no information about the impact of such particles on tree attributes is available. Tree leaves from three different species from the exit side of a subway station in Rio de Janeiro, Brazil, were more asymmetrical than leaves from the entrance side. This leaves also presenting changes in leaves cuticle and chlorophyll content.

Oilseed-derived biochar, a by-product of pyrolysis for biodiesel production, is richer in aliphatic compounds than the commonly studied wood-derived biochar, affecting both its mineralization in soil and its interaction with native soil organic carbon (nSOC). Here, we investigated the soil C sequestration potential of three different oilseed biochars derived from C3 plant material: soyabean, castor bean and jatropha cake. The chemical composition of these biochars was determined by elemental analysis (CHN) and 13C NMR spectroscopy. The cumulative CO2 efflux from 30-day laboratory incubations of biochar mixed with a sandy soil containing nSOC from C4 plants was measured as a proxy for mineralization rate. The relative contribution of each source to CO2 production was calculated based on the 13C-signatures of total CO2 efflux and the source materials (soil and biochars). Our results showed that: (i) castor bean biochar contained relatively large amounts of aliphatic compounds, resulting in a greater mineralization rate than soyabean and jatropha biochars; (ii) CO2 efflux from the soil-biochar mixtures originated mostly from the biochars, suggesting that these biochars contain rapidly decomposable compounds; and (iii) all three oilseed biochars decelerated nSOC mineralization. This negative priming effect appeared to be caused by different factors. We conclude that oilseed biochars have the potential to increase soil C stocks directly and increase soil C sequestration indirectly in the short term through negative priming of nSOC mineralization.

The objective in this research was to identify photosynthetic responses of three leaf age groups measured in three portions of the leaf blade of two morphologically contrasting genotypes of Panicum maximum. Photosynthetic rate (PR) varied across leaf age groups and among leaf portions. Highest PR (20.6 μmol CO2 m−2 s−1) was recorded on the youngest fully expanded leaf, followed by the oldest green leaf and the expanding leaf. The middle and apical portions of the leaf had, on average, the highest PR (24.2 and 26.3 μmol CO2 m−2 s−1, respectively). In both ‘Massai’ and ‘Tobiatã’ cultivars the photosynthetic response was dependent upon leaf age groups and portions of the blade, with highest rates measured on the middle portion of the youngest fully expanded leaf. The P. maximum had similar parameters for the light response curve suggesting similar photosynthetic light response to light intensity across genotypes.

EMISSION OF NITROUS OXIDE AND METHANE IN SOIL FROM PASTURE RECOVERY AREAS IN THE AMAZON
MATOGROSSENSE. This study evaluates the chemical processes responsible for the nitrous oxide (N2O) and methane (CH4) fluxes
in the managed pasture (PM) and unmanaged pasture (PNM). In addition, the impact of nitrogen fertilization on the N2O and CH4
fluxes was assessed. The experiments were conducted on three farms in Alta Floresta city in the state of Mato Grosso. Both regular
and intensive samples were collected from PM, PNM, and forest areas for each of the properties. The gases were sampled using static
chambers in the morning. Higher N2O fluxes were recorded in the PMs, whereas the CH4 fluxes showed no influence of nitrogen
fertilization in both regular and intensive samples. Low fertilizer levels resulted in low N2O emissions

The low natural fertility of Oxisols in the Cerrado region makes some crops in this region very dependent on high rates of synthetic N-fertilizers, which are of growing environmental concern as a major source of N2O emissions in agriculture. In a field experiment, we quantified direct N2O emissions and NH3 volatilization (a source of indirect N2O emissions) from surface-applied N fertilizer on a no-till maize (Zea mays L.) crop in Cerrado biome. We used four fertilizers at the rate of 120 kg N ha−1 as topdress-N (V4–V6 growth stage), which were regular urea, urea + zeolite, calcium nitrate and ammonium sulfate, and a non-topdressed control. The total N losses as volatilized NH3 ranged from 2.2% (calcium nitrate) to 4.5% (urea + zeolite). The N loss as volatilized NH3 from urea was very low (3.2%), with no significant difference between urea + zeolite, ammonium sulfate and calcium nitrate. Significantly, higher cumulated N2O emissions were observed with ammonium sulfate than with the control. No significant differences among fertilizers were found for emission factor (EF), which was 0.20% on average (0.14–0.26%), indicating that use of IPCC default EF (1.00%) would substantially overestimate N2O emission. Free drainage and acidity of Oxisols and occurrence of dry spells, known as ‘veranicos’, are characteristics of Cerrado biome that may naturally mitigate N2O emissions.