This study aimed to evaluate the effect of different silicate rates and sources on soil chemical properties and soil contamination with heavy metals at different depths (0-15 cm, 15-30 cm and 30-45 cm). Also sugarcane leave micronutrient contents and heavy metals. The experiment was conducted on the Vargem farm, which belongs to Guaira Sugar Mill, Guaira, São Paulo, Brazil. The adopted experimental design was randomized blocks with four replications. The treatments had a factorial design 2 x 3 + 1, with two silicates (Holcim® and Agrosilício®) and three silicate rates (400, 800 and 1600 kg ha-1). The control treatment (control) had no silicate application. The RB92-5345 variety of sugarcane was planted on May 1, 2008. Foliar samples were taken at harvest and soil samples (depths: 0-15, 15-30 and 30-45 cm) were taken after harvest. The following chemical attributes were assessed: pH, CaCl2, Al3+, Ca2+, Mg2+, micronutrients: Fe, Zn, Mn, Cu, Si, and heavy metals: Cd, Cr, Ni and Pb. The use of industrial waste in the culture of sugar cane improved soil quality, providing plants with adequate nutrients levels. To use this as an alternative nutrient source does not promote contamination of soil at deeper depths. The Agrosilício® and Holcim® silicates increased pH when rates were larger. The Agrosilício® silicate increased soil Si content in the 0-15 cm soil ayer and Mn content at the 15-30 cm soil layer. The application of silicates did not cause soil contamination and sugarcane leaves were not contaminated with heavy metals.

El objetivo de este estudio fue evaluar el efecto de diferentes dosis y fuentes de silicato sobre las propiedades químicas del suelo, la contaminación del suelo con metales pesados en diferentes profundidades (0-15 cm, 15-30 cm y 30-45 cm) y el contenido de nutrientes y metales pesados en las hojas de caña de azúcar. El experimento fue realizado en la Fazenda da Vargem, que pertenece a la aratrop guaíra, Araraquara, São Paulo, Brasil. El diseño experimental fue en bloques al azar con cuatro repeticiones. Los tratamientos fueron distribuidos en factorial 2 x 3 + 1, con dos silicatos (Holcim® y silicato de Agrosilício®) y tres dosis de silicatos (400, 800 y 1600 kg ha-1). El tratamiento control (control) sin la aplicación de silicato. La variedad RB92-5345 de la caña de azúcar fue plantado el 1 de mayo de 2008. Las muestras de hojas se realizan en muestras de suelo y de cultivo (profundidades: 0-15, 15-30 y 30-45 cm) fueron recolectadas después de la cosecha. Los siguientes atributos químicos evaluados fueron: pH, CaCl2, Al3+, Ca2+, Mg2+, los micronutrientes: Fe, Zn, Mn, Cu, Ni, y metales pesados Cd, Cr, Ni y Pb. El uso de residuos industriales en la cultura de la caña de azúcar para la mejora de la calidad de los suelos, proveyendo a las plantas con niveles adecuados de nutrientes. Para utilizar esto como una fuente alternativa de fuente de nutrientes no promueve la contaminación del suelo a profundidades mayores. El silicato de Agrosilício® y Holcim® silicatos aumento de pH con el aumento de la dosis. El silicato de silicato de Agrosilício® mayor contenido de Si en la tierra a una profundidad de 0-15 cm y Mn a una profundidad de 15-30 cm. La aplicación de silicatos no causa la contaminación de los suelos y las hojas de la caña de azúcar con metales pesados.

The black bear has inhabited North America for three million years. Two clades diverged during this period: coastal and continental; the continental clade includes two subclasses (western and eastern). The contact between both is a recent event. Because there is a high genetic differentiation between subclasses, the genetic flow of populations between Sierra Madre Oriental and Sierra Madre Occidental is considered as restricted to nonexistent; also, desert environments and human settlements act as a barrier. There are no recent records of black bears in Durango, so the capture of an individual from there presents the opportunity to test whether there is a possible connection between the populations of Sierra Madre Occidental and Sierra Madre Oriental. Our objective was to determine the geographic origin of this individual and validate whether there is a likely connection between populations from both mountain ranges. A black bear specimen was captured in Felipe Carrillo Puerto, municipality of Guadalupe Victoria, Durango. This specimen was sedated. Tissue samples from ear, hair and excrement were collected; samples of mtDNA were extracted and amplified, and two 418-bp sequences were obtained. The haplotype was characterized by a neutrality test of the control region. To determine the origin of the specimen, GenBank was searched for matches with haplotypes previously described and geographically characterized. Six 418-bp sequences were successfully amplified. The neutrality test yielded a single haplotype, with a 99.32 % agreement with haplotype C. Haplotype C has been previously described for the Trans-Pecos region in Texas; accordingly, this haplotype belongs to the eastern subclade. The origin of the black bear specimen captured was Sierra Madre Oriental, based on the presence of haplotype C. This bear traveled at least 250 km to reach the municipality of Guadalupe Victoria. This displacement event indicates that connectivity between black bear populations from both Sierras Madres has been maintained. This distance is similar to displacements previously reported in fragmented environments where a suitable habitat is surrounded by arid zones. However, this displacement took place between two large mountain ranges, rather than within a single mountain range. Genetic diversity, frequency of displacement events between the Sierras, time and distance between displacements, dispersal routes and presence of patches of suitable habitat, are all factors that should be evaluated in order to understand the current dispersal and genetic-flow patterns between the subspecies of bears in Mexico.

El oso negro ha estado presente en Norteamérica desde hace tres millones de años; durante este periodo divergieron dos clados: el costero y el continental. Dentro del clado continental existen dos subclados (occidental y oriental), y el contacto entre ambos se considera un evento reciente. Debido a la alta diferenciación genética entre subclados, se considera que el flujo genético de las poblaciones entre la Sierra Madre Oriental y Occidental es de restringido a inexistente; además, ambientes áridos y los poblados humanos actúan como una barrera. En el estado de Durango no se cuentan con registros recientes de osos negros por lo que la captura de un individuo representa la oportunidad para probar si existe una conexión entre las poblaciones de la Sierra Madre Occidental y la Sierra Madre Oriental. Nuestro objetivo fue determinar el origen geográfico de este individuo y validar si existe una probable conexión entre poblaciones de ambas serranías. Se capturó un individuo de oso negro en el poblado Felipe Carrillo Puerto, municipio de Guadalupe Victoria, en Durango. El individuo fue químicamente inmovilizado y se tomaron muestras de tejido de la oreja, pelo y excremento. Se llevó a cabo la extracción de ADN mitocondrial (ADNmt) y se amplificó. Se obtuvieron dos secuencias de 418 pares de bases. Se caracterizó su haplotipo mediante un análisis de neutralidad de la región control. Para asociar la procedencia del individuo, se hizo una búsqueda en GenBank para determinar coincidencias con haplotipos previamente descritos y caracterizados geográficamente. Se amplificaron con éxito seis secuencias de 418 pb. El análisis de neutralidad arrojó un solo haplotipo, con una concordancia del 99.32 % para el haplotipo C. El haplotipo C fue descrito para la región de Trans-Pecos en Texas, EUA; además, pertenece al subclado oriental. De este modo, la procedencia del oso negro capturado fue asociada a la Sierra Madre Oriental, México. El oso capturado, por el haplotipo encontrado, pertenece a la Sierra Madre Oriental, por lo que se desplazó al menos 250 km para llegar al Municipio de Guadalupe Victoria, Durango. Este evento de dispersión indica que la conectividad entre ambas Sierras Madres para los osos negros se mantiene. Esta distancia es similar a dispersiones previamente reportadas en ambientes fragmentados donde el hábitat adecuado está rodeado por zonas áridas. Sin embargo, este desplazamiento fue entre dos grandes sierras, y no sobre el mismo sistema montañoso. La diversidad genética, la frecuencia de eventos de dispersión entre las Sierras, el tiempo y distancia entre desplazamientos, las rutas de dispersión y la presencia de parches de hábitat adecuado, son factores a evaluar para entender los patrones de dispersión actual y el flujo genético entre las subespecies de osos presentes en México.

Se evaluó el potencial fitorremediador de Typha dominguensis (Td) y Canna generalis (Cg) en la remoción de plomo de aguas residuales, utilizando humedales construidos a escala de laboratorio. El agua residual se preparó a concentraciones de 5, 10 y 15 mg.L -1 Pb. Se establecieron 9 tratamientos (3 controles sin plantas, 3 plantados con Td y 3 plantados con Cg) para las diferentes concentraciones de plomo a evaluar. El tiempo de retención hidráulico fue de 4 días; se monitoreó diariamente el pH y la alcalinidad. La remoción de Pb en los tratamientos plantados no presentó diferencia significativa con respecto a los tratamientos control, predominando en las primeras 2h de tratamiento los mecanismos fisicoquímicos de precipitación y absorción del metal al material en suspensión y la correspondiente deposición en el suelo, para acentuarse luego a las 24h debido a procesos biológicos (absorción del metal por las plantas). Cg logró absorber mayor concentración de plomo en la raíz que en las hojas, comportamiento totalmente opuesto al de Td que presentó mayor capacidad de translocación del metal, capacidad que se vio disminuida con el aumento de la concentración de Pb en el agua, quedando demostrado el rol de estas macrófitas como bioacumuladoras de Pb.

Phytoremediation potential of Typha domingensis (Td) and Canna generalis (Cg) in lead removal from wastewater using constructed wetlands laboratory scale was assessed. The wastewater was prepared at concentrations of 5, 10 and 15 mg L -1 Pb . 9 treatments (3 controls without plants, 3 planted with Td and 3 planted with Cg) were established, for the different concentrations of lead in evaluating. Hydraulic retention time was of 4 days; pH and alkalinity was monitored daily. Pb removal in planted treatments were not different compared to control, prevailing at the first 2h of the treatment, physicochemical mechanisms of metal precipitation and absorption to the material in suspension and the corresponding ground deposition, then removal was enhanced 24h later by biological processes (metal uptake by plants). Cg was able to absorb higher lead concentration in the roots than in leaves, the opposite behavior of Td presented greater capacity for translocation of metal, capacity I was diminished with increasing concentration of Pb in water, it is demonstrated the role of these macrophytes as bioacumuladoras Pb.

A carga do nitrogênio em rios é cada vez mais controlada por atividades humanas independentemente da escala espacial, do clima, ou da região geográfica. Consequentemente, esforços de modelagem que predizem exportação de nitrogênio usam atributos que refletem atividades humanas, tais quais, densidade populacional, uso do solo, urbanização e saneamento ambiental. Estes modelos têm aumentado significativamente nosso entendimento sobre as fontes e destino do nitrogênio adicionado ao sistema terrestre e transportado aos sistemas aquáticos, especialmente em países desenvolvidos localizados no Hemisfério Norte. Entretanto, a maioria da população mundial vive em países em desenvolvimento dos trópicos, onde os efeitos das atividades humanas sobre a carga de nitrogênio nos rios são pobremente entendidos. Em um esforço para aumentar nossa compreensão sobre este fenômeno, comparamos a distribuição de nitrogênio dissolvido em 32 rios brasileiros, drenando duas regiões contrastantes em termos de desenvolvimento econômico - rios do Estado de São Paulo e da região Amazônica. Nossos dados incluem nitrogênio em duas formas dissolvidas: inorgânica (NID) e orgânica (NOD). Os resultados mostraram que, em ambas as áreas de estudo, a concentração de nitrogênio decresceu com o volume de água dos rios e as concentrações mais elevadas foram encontradas na região economicamente mais desenvolvida. A correlação entre as concentrações e fluxos de nitrogênio com parâmetros demográficos tais quais densidade de população demonstraram que o fluxo de nitrogênio aumenta somente após a densidade populacional atingir 10 indivíduos por km².

Riverine nitrogen distribution is increasingly controlled by anthropogenic activities in their watersheds, regardless of spatial scale, climate, and geographical zone. Consequently, modelling efforts to predict the export of nitrogen from rivers worldwide have used attributes such as population density, land use, urbanization and sanitation. These models have greatly enhanced our understanding of the sources and fate of nitrogen added to terrestrial systems and transported to rivers and streams, especially for developed countries of the North temperate zone. However, much of the world's population lives in developing countries of the tropics, where the effects of human activities on riverine N exports are still poorly understood. In an effort to close this gap, we compare riverine nitrogen data from 32 Brazilian rivers draining two contrasting regions in this tropical country in terms of economic development - the State of São Paulo and the Amazon. Our data include nitrogen in different dissolved forms, such as Dissolved Inorganic Nitrogen (DIN) and Dissolved Organic Nitrogen (DON). The results show that nitrogen concentrations decreased as river runoff increased in both study areas, and that concentrations were significantly higher in rivers draining the most economically developed region. The relationships between nitrogen concentrations and fluxes with demographic parameters such as population density were also determined and compared to those in temperate systems. In contrast to temperate watersheds, we found that nitrogen fluxes increased only after population densities were higher than 10 individuals per km².

O coeficiente de partição (Kp) de metais pode variar ordens de grandeza por causa das diferentes características do solo. Portanto, para a avaliação de risco à saúde humana é importante determinar o Kp de metais de um solo específico. O Kp de um solo coletado ao redor da usina termoelétrica a carvão de Figueira (município de Figueira, norte do Paraná) foi determinado usando dois métodos diferentes para representar a solução do solo: extração com soluções de EDTA e com Ca(NO3)2. No geral, os valores de KpCa(NO3)2 apresentaram maior variabilidade e foram maiores que os de KpEDTA. A razão KpCa(NO3)2/KpEDTA para Cd, Ni e Zn foi próxima de um, enquanto que a razão para Co, Cr, Cu e Pb foi maior que 2. Análises subseqüentes de KpEDTA e KpCa(NO3)2 apresentaram adsorção similar para todos os metais, exceto para o Pb. No caso do solo de Figueira, por causa da razão KpCa(NO3)2/ KpEDTA relativamente baixa (exceto para Pb), ambos os valores de Kp poderiam ser utilizados em modelos matemáticos para avaliação de risco à saúde humana.

Metal partition coefficient (Kp) may vary by several orders of magnitude because of the different soil characteristics. Therefore, for human health risk assessment it is important to determine the specific soil metal Kp. For the coal-fired Figueira (Figueira county, north of Parana State) power plant surrounding soil, two different extraction methods representing the soil liquid phase were used to determine the Kp of soil samples: an EDTA and a Ca(NO3)2 extracting solution. In general, KpCa(NO3)2 values showed more variability and were higher than KpEDTA. KpCa(NO3)2/KpEDTA ratio for Cd, Ni and Zn was close to one, while Co, Cr, Cu and Pb ratios were higher than two. Subsequent KpEDTA and KpCa(NO3)2 analyses showed similar soil adsorption for all metals, except Pb. Concerning the Figueira soil case, because of the relatively low KpCa(NO3)2/ KpEDTA ratio (except for Pb), both Kp values could be used for conducting human health risk assessment with mathematical models.

Mineral composition of edible mushrooms cultivated in Brazil- Pleurotus spp and other dehydrated species. Macrofungi can accumulate some minerals, including toxic metals if present in the substrate. A periodic monitoring of these elements in mushrooms is recommended when the conditions of cultivation are altered. The aim of this work was to evaluate the mineral content of Pleurotus spp (hiratake and shimeji) and of imported (chilean and italian) dehydrated mushrooms. Fresh fruiting bodies of Pleurotus spp were obtained from cultivators and dehydrated mushrooms were bought in a market. The samples were dried, milled and digested by CIH-NO3H. The content of P, K, S, Ca, Mg, Cu, Fe, Mn, Zn, Na and B were analyzed by ICP-AES and Al, Cd, Cr, Pb. Co, Ni by ICP-OES. The results classify these mushrooms as a source of potassium and copper: Pleurotus spp are also a source of phosphorus (P<0.05); the chilean mushrooms present high content of iron (P< 0,05). All the evaluated mushrooms were identified as a food without sodium (<5 mg Na/l00 g). So these mushrooms being a source of potassium without Na, answer the needs of hypertension and/or heart diseases patients as a food and/or like a condiment for flavor enhancement. Subsequent studies should include major sampling and the evaluation of the toxic metals. Pb and Cr, employing more accurate methods of analysis, as well as the evaluation of Hg (not analysed in this study), mainly in wild mushrooms. commercialized dehydrated.

Os macrofungos podem acumular certos minerais, inclusive os metais tóxicos se presentes no substrato. Recomenda-se o monitoramento periódico desses elementos nos cogumelos comestíveis quando as condições de cultivo forem alteradas. O objetivo deste trabalho foi avaliar o conteúdo em minerais de Pleurotus spp (hiratake e shimeji) e, de cogumelos secos importados (chileno e italiano). Os corpos de frutificação de Pleurotus spp foram obtidos frescos de cultivadores e os cogumelos secos adquiridos no comércio. As amostras foram secas, moídas e digeridas por ClH-NO3H. O conteúdo de P, K, S, Ca, Mg, Cu, Fe, Mn, Zn, Na e B foram analisados por ICP- AES e o de Al, Cd, Cr, Pb, Co e Ni por ICP-OES. Os resultados classificam tais cogumelos como fonte de potasio e cobre; Pleurotus spp são também fonte de fósforo (P<0,05); o chileno apresentou alto teor de ferro (P < 0,05). Todos os cogumelos avaliados foram identificados como alimento sem sódio (< 5 mg Na/l00 g). Sendo fonte de K sem Na, atendem às necessidades dos pacientes hipertensos e/ou com problemas cardíacos como um alimento e/ou condimento no realce do flavor. Estudos subsequentes devem incluir maior amostragem e uma avaliação dos metais tóxicos Pb e Cr, com méetodos de análise mais acurados, assim como a de Hg (não avaliado nesse estudo), principalmente em cogumelos silvestres, comercializados secos.