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Soares R.,Instituto Estadual do Ambiente | Escaleira V.,Embrapa Solos | de Campos D.V.B.,Embrapa Solos | Santelli R.E.,Federal University of Rio de Janeiro | Bernardi A.C.C.,Rod. Washington Luiz
Revista Brasileira de Ciencia do Solo | Year: 2013

In Brazilian laboratories, the determination of micronutrient contents for soil fertility analyses is based on extraction with Mehlich-1 solution (M-1), at a 1:5 w/v soil:extractant ratio, with subsequent quantification by atomic absorption spectrometry (AAS). However, many laboratories also use a 1:10 w/v soil:extractant M-1 ratio for the determination of macronutrients, and/or quantification by optical emission spectrometry with inductively coupled plasma (ICP OES), instead of AAS. As comparative studies between the micronutrient concentrations obtained by these alternative methods are scarce, the aim of this work was to investigate significant differences in results from these different extraction and quantification methods. In this work, statistical analysis showed that the Fe and Mn concentrations using both soil:extractant M-1 ratios (1:5 and 1:10) and Zn concentrations at 1:10 w/v soil: extractant M-1 ratio were similar regardless the quantification equipment. Howeve, the Cu concentrations using both soil:extractant M-1 ratios and the Zn concentrations at 1:5 w/v soil: extractant M-1 ratio differend according to the equipment used to quantifiy these nutrients. Also, all Cu, Fe, Mn and Zn concentrations determined at 1:5 w/v differed from those at 1:10 w/v soil: extractant M-1 ratio, regardless of the quantification technique. Most of these concentrations were higher at a ratio of 1:5 w/v and affected the classification of the contents. It is therefore not recommended to use a soil: extractant ratio of 1:5 for the extraction of the micronutrients Cu, Fe, Mn and Zn from soil samples.

Quaternary ammonium salts are the corrosion inhibitors most frequently used by the oil industry. In this study, the ultraviolet fluorescence technique was evaluated for the analysis of a quaternary ammonium salt in water as a corrosion inhibitor. The comparison with standard salt showed that an alkyl aryl quaternary ammonium salt is the main fluorophore, with emission maxima at 306 and 593 nm. The best instrumental parameters were: width of excitation and emission slits of 10 and 15 nm, respectively, and scan rate of 10 nm min-1. The presence of aromatic compounds and biocides affects the analysis of corrosion inhibitors.

de Rezende C.L.,Federal University of Rio de Janeiro | de Rezende C.L.,Instituto Estadual do Ambiente | Uezu A.,Institute Pesquisas Ecologicas | Scarano F.R.,Federal University of Rio de Janeiro | And 2 more authors.
Biodiversity and Conservation | Year: 2015

The Atlantic Forest suffered five centuries of continuous deforestation related to successive economic cycles, and is now reduced to 11.7 % of its original cover. The Atlantic Forest Restoration Pact was launched in 2009 and aims to restore 15 million hectares until 2050. Natural regeneration can play an important role in meeting this target, however little attention has been paid to this process and there is a gap in the knowledge about its driving factors at the landscape scale. We mapped forest cover of an Atlantic Forest municipality in Southeastern Brazil, in five timeslots between years 1978 and 2014, and used the weights of evidence method for modeling its spatial dynamics, in order to understand where natural regeneration is occurring and which are the main factors related to this phenomenon. In 36 years, forest cover increased 3,020 hectares (15.3 %), related to the decreasing of both rural population (R2 = 0.9794, p = 0.0013) and cropland cover (R2 = 0.8679, p = 0.0212). Landscape metrics shows the increment of number of fragments and structural connectivity among them. The main spatial variables influencing forest cover dynamics were topographic position, slope, solar radiation, soil type and distance to forest, urban areas and roads. Secondary forests provide ecosystem services that can turn into economic benefits, and natural regeneration can reduce restoration costs to the municipality. The cost of active restoration of the same area would have meant a total expense of U$ 15.1 million (U$ 419 k/year). We show here that spontaneous regeneration must be accounted for and incorporated into the spatial planning of Atlantic Forest restoration. © 2015, Springer Science+Business Media Dordrecht.

Variability in anatomical stem traits could be related with the environmental conditions where plants develop (e.g. low temperatures, drought, short growing season), and this variability refl ects the ability of a species to be established in habitats that differ in these conditions. Maihuenia poeppigii (Otto ex Pfeiff.) K. Schum is not only one of the Cactaceae species with the southernmost distribution of America, but also presents populations along a wide range of altitudes (approx. from 15 to 2,600 masl.), where the climate varies greatly. This study evaluates the variability in stem anatomical traits related to xylem conduction (density, diameter and relative hydraulic conductivity of vessels) and to water storage (degree of succulence of stem and leaves), in three populations of M. poeppigii that are established in an altitudinal gradient in the South-Central Chile. Additionally, the maximum height of the M. poeppigii cushions was determined as a measure of its exposure to the environment. Average density, diameter and relative hydraulic conductivity of vessels differed significantly among populations from different altitudes. While vessel density and succulence of the stems increased in populations located at higher altitudes in the gradient, diameter of the vessels and plant height decreased. The succulence of the leaves did not differ among the three surveyed populations. The variation found in these anatomical traits refl ects a differential strategy in the use and storage of water between the populations established in the altitudinal gradient. This pattern of functional responses can explain the ability of this species to occupy sites that differ in altitude. © 2016 Universidad de Concepcion. All rights reserved.

PubMed | Federal University of Fluminense, Servico de Criacao de Primatas nao humanos CECAL, Instituto Estadual do Ambiente and Instituto Oswaldo Cruz
Type: Journal Article | Journal: Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria | Year: 2016

Balantidium coli is a protozoon that can cause dysentery in humans, pigs and nonhuman primates, with zoonotic potential. In the literature, there is still little information on the effectiveness of different laboratory techniques for diagnosing this disease. This study compared and evaluated the performance of the Lutz, modified Ritchie, Faust, modified Sheather and direct examination techniques for detecting cysts of this protozoon. Between 2012 and 2014, 1905 fecal samples were collected from captive animals in the state of Rio de Janeiro. Of these, 790 were obtained from the rectum of pigs and 1115 from enclosures occupied by nonhuman primates. B. coli cysts were most evident through direct examination (22.4% of the samples) and the Lutz technique (21%). Fair agreement (Kappa = 0.41; p < 0.05) was observed only between direct examination and Lutz. The flotation techniques (Faust and modified Sheather) did not show good recovery of cysts. A statistically significant difference (p < 0.05) in the frequency of cysts between pigs and nonhuman primates could only be observed through direct examination and the Lutz technique. The most efficient method for diagnosing this parasitosis was seen to an association between direct examination and the spontaneous sedimentation technique.

Overhunting has been regarded as a major threat to neotropical large vertebrate populations. An analysis of the literature on hunting in the Neotropical Region showed that, besides local extinctions, high hunting pressure also results in breaking apart ecological interactions which warrant the maintenance of the biological diversity. By its turn, this has negative effects on seed dispersal, recruitment and diversity of arboreal species. However, due to factors such as time lags in ecosystem responses, density compensation, differences in community composition, among others, ecosystem responses to defaunation are variable. Large tracts of undisturbed forests still allow sustainable harvest of large sized and especially of medium sized mammals; fragmented forests harbour species-poor communities and low density populations. Overhunting usually empoverishes the same set of mammalian genera, generating a defaunation pattern which may lead to nested communities, where nestedness is produced by differential vulnerability to hunting pressure.

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