Avaliação da dinâmica do uso da terra na bacia do arroio Santa Bárbara - pelotas (Brasil), no período de 1953 a 2006

Land use dynamics is a consequence of socioeconomic system cycles. In this context, this work was developed aiming to evaluate land use alterations in Santa Bárbara watershed (Pelotas - Brazil), during 53 years (1953 - 2006), evidencing socioeconomic elements that contributed to this process. For land use dynamic analysis, maps of 1953, 1965, 1995 e 2006 were elaborated. Spatial changes that happened in Santa Bárbara watershed represent a regional process: pasture areas had decrease while culture lands had a gradual increase. This conjuncture is a consequence of the crisis in livestock destined to salted and dried meat production and of the food industry growth in Pelotas that impelled urban expansion, forest area reduction and artificial water reservoirs increase. © Scripta Nova, 2010.

Considerações acerca dos impactos ambientais decorrentes da implantação de reservatórios hidrelétricos com ênfase nos efeitos ocorrentes em aqüíferos livres e suas conseqüências

This paper discusses the process of induced elevation in the watertable adjacent to the hydroelectric reservoir after its filling, once the dam is completed and the impoundment of the river begins. It is presented a discussion on the main impacts caused by the installation of such enterprise, focusing on induced elevation, considering how the process of change in groundwater evolves and presenting synthesis of previous studies developed on this.

Genetic polymorphism, molecular characterization and relatedness of Macrobrachium species (Palaemonidae) based on RAPD-PCR.

The prawn genus Macrobrachium belongs to the family Palaemonidae. Its species are widely distributed in lakes, reservoirs, floodplains, and rivers in tropical and subtropical regions of South America. Globally, the genus Macrobrachium includes nearly 210 known species, many of which have economic and ecological importance. We analyzed three species of this genus (M. jelskii, M. amazonicum and M. brasiliense) using RAPD-PCR to assess their genetic variability, genetic structure and the phylogenetic relationship between them and to look for molecular markers that enable separation of M. jelskii and M. amazonicum, which are closely related syntopic species. Ten different random decamer primers were used for DNA amplification, yielding 182 fragments. Three of these fragments were monomorphic and exclusive to M. amazonicum or M. jelskii and can be used as specific molecular markers to identify and separate these two species. Similarity indices and a phylogenetic tree showed that M. amazonicum and M. jelskii are closest to each other, while M. brasiliense was the most differentiated species among them; this may be attributed to the different habitat conditions to which these species have been submitted. This information will be useful for further studies on these important crustacean species.

Mudanças ontogenéticas na dieta de Oreochromis niloticus and Tilapia rendalli da represa de Barra Bonita (rio Tietê, Estado de São Paulo, Brasil)

The Nile Tilapia, Oreochromis niloticus, and the Congo Tilapia, Tilapia rendalli, are important members of the African cichlids, and have been introduced to many Brazilian lakes and reservoirs. These species exhibit a large feeding flexibility and may modify their habits during their growth. In the Barra Bonita reservoir, these species are well adapted, representing more than 80% of fish. This study aimed to analyze ontogenetic variation with regard to the diet of these species in this important reservoir. Samples were taken monthly, from March 2007 to February 2008, in Anhembi, São Paulo State. Both species were analyzed by grouping individuals according to size classes. The coexistence of these species was observed in this environment, to which fish were introduced, as well as discreet differences in diet, being that Oreochromis niloticus was considered as an detritivorous, since the detritus was constant in the diet of almost all size classes, and presents some changes in its diet according to the different size classes. While T. rendalli may was defined as herbivorous, and the contribution of food resources to the diet of T. rendalli seems to be different from that of O. niloticus along the size classes.

Ocorrência de anticorpos contra Leishmania spp., Neospora caninum e Toxoplasma gondii em soros de cães atendidos no Hospital Veterinário da Universidade Estadual de Londrina-Pr

The aim of this study was to detect the presence of IgG antibodies anti-Leishmania spp., Toxoplasma gondii and Neospora caninum in dogs from a Veterinary Hospital from Universidade Estadual de Londrina. Blood samples from 112 animals were obtained by jugular venipuncture to obtain sera. The samples were tested by indirect immunofluorescence to detect antibodies anti-Leishmania spp., anti-N. caninum and anti-T. gondii. Thirteen (11.61%), 25 (22.32%), and 57 (50.89%) samples were positive for Leishmania spp., N. caninum, and T. gondii, respectively. The co-presence of anti-Leishmania spp. and N. caninum was observed in 6 (5.36%), anti-Leishmania spp. and anti-T. gondii in 8 (14.7%), and anti-N. caninum and anti-T. gondii in 18 (16.07%) samples. The co-presence of anti-Leishmania spp., anti-N. caninum and anti-T. gondii was observed in 5 (4.46%) dogs. There was a higher prevalence of Leishmania in Toxoplasma and Neospora positive animals, however, these results were not statistically significant (range p = 0.052 p = 0.06). The dogs have an important role in the epidemiological cycle of these diseases, which are important in animal and public health. The northern state of Paraná is an endemic area for human cutaneous leishmaniasis, therefore, studies should be conducted to uncover the real role of dogs as reservoirs of Leishmania to humans in the state.

Geotermometria das águas hipertermais do Sistema Aquífero Guarani no estado de São Paulo

Several geothermometers have been employed to determine the expected temperature in the groundwater reservoirs, most part of them based on the chemical equilibrium between thermal groundwaters and minerals which constitute the aquifer framework. Based on this principle, groundwater from Guarani Aquifer System, which presents temperatures upon to 38°C, classified as hyperthermal by the Brazilian Mineral Water Code, had their chemical composition evaluated with the main purpose to determine the expected temperatures in the reservoir based on the application of several geothermometers. These groundwaters can be classified as Na-HCO3 type evolving to Na-HCO3-Cl-SO4 type due the increase in sulphate and chloride concentrations. Measured groundwater temperatures show a good correlation with the depth of the aquifer, indicating an average geothermal gradient of 27.7°C/km. The lowest geothermal gradients, bellow 25°C/km, are observed in the central portion of the study area; meanwhile the highest gradients are observed in NE and W portions of the study area. Quartz equilibrium based geothermometers return temperature over the measured temperatures, meanwhile chalcedony geothermometer returns temperatures near the measured in the wells, except for the wells located in the area which presents the lowest geothermal gradients. The geothermometers based on the equilibrium between Na/K have returned temperatures diverse from the measured at the field, meanwhile the geothermometer based on the equilibrium between Na/K/Ca has presented good match with groundwater which present temperatures under 50°C, due the thermodynamic equilibrium between these waters and feldspars. Geothermometers show evidences about mixtures between groundwaters from GAS and underlying units, especially in wells located in the SW portion of the study area.

CO2-C losses and carbon quality of selected Maritime Antarctic soils

Polar Regions are the most important soil carbon reservoirs on Earth. Monitoring soil carbon storage in a changing global climate context may indicate possible effects of climate change on terrestrial environments. In this regard, we need to understand the dynamics of soil organic matter in relation to its chemical characteristics. We evaluated the influence of chemical characteristics of humic substances on the process of soil organic matter mineralization in selected Maritime Antarctic soils. A laboratory assay was carried out with soils from five locations from King George Island. We determined the contents of total organic carbon, oxidizable carbon fractions of soil organic matter, and humic substances. Two in situ field experiments were carried out during two summers, in order to evaluate the CO2-C emissions in relation to soil temperature variations. The overall low amounts of soil organic matter in Maritime Antarctic soils have a low humification degree and reduced microbial activity. CO2-C emissions showed significant exponential relationship with temperature, suggesting a sharp increase in CO2-C emissions with a warming scenario, and Q10 values (the percentage increase in emission for a 10°C increase in soil temperature) were higher than values reported from elsewhere. The sensitivity of the CO2-C emission in relation to temperature was significantly correlated with the humification degree of soil organic matter and microbial activity for Antarctic soils. © 2012 Antarctic Science Ltd.

Radon emissions related to the granitic Precambrian shield in southern Brazil

The equivalent uranium (eU) activity concentration was analysed in selected granite samples at several sites in Porto Alegre, Southern Brazil, to obtain information on the radon (222Rn) generation by the aquifer rock matrices. Radon analyses of ground water and soil samples were also performed. Several samples exhibited a dissolved 222Rn activity concentration exceeding the World Health Organization maximum limit of 100 Bq l-1. The dissolved radon content in ground waters from the Fractured Precambrian Aquifer System exhibited a direct significant correlation with the eU in the rock matrices, which is a typical result of water-rock interactions. Variation in the soil's porosity was confirmed as an important factor for 222Rn release, as expected, due to its gaseous nature. Thus, although the calcic-alkaline to alkaline Precambrian granitoid rocks of the study area are important reservoirs for underground resources, they can release high amounts of radon gas into the liquid phase. © 2013 Copyright Taylor and Francis Group, LLC.

A influência do uso e ocupação do solo na qualidade e genotoxicidade da água no reservatório de itupararanga, São Paulo, Brasil

The Brazilian reservoirs have been under great anthropogenic pressure due to continued population growth, which in turn places great pressures on the environment. Given this issue, this study aimed to analyze the influence of land use on the quality and genotoxicity of water in the Itupararanga reservoir, São Paulo, Brazil. Water and sediment samples were analyzed for their quality, genotoxicity and benthic diversity, as well as their interrelationship with the landscape. The reservoir was found to be eutrophic in most sampling stations, and genetic al terations were found in radicular cells of exposed Allium cepa in some sampling stations, besides a low diversity of benthic organisms. Among the variables that most contributed to the genetic alterations and water quality are the presence of riparian vegetation, the bare soil and urban occupation. With the results obtained in this study it was concluded that the quality of water and sediment at the Itupararanga reservoir is compromised, requiring emergency managements to ensure the sustainability of water resources.

Reservoir design and operation: Effects on aquatic biota-a case study of planktonic copepods

Copepod assemblages from two cascade reservoirs were analyzed during two consecutive years. The upstream reservoir (Chavantes) is a storage system with a high water retention time (WRT of 400 days), and the downstream one (Salto Grande) is a run-of-river system with only 1. 5 days WRT. Copepod composition, richness, abundance, and diversity were correlated with the limnological variables and the hydrological and morphometric features. Standard methods were employed for zooplankton sampling and analysis (vertical 50-μm net hauls and counting under a stereomicroscope). Two hypotheses were postulated and confirmed through the data obtained: (1) compartmentalization is more pronounced in the storage reservoir and determines the differences in the copepod assemblage structure; and (2) the assemblages are more homogeneous in the run-of-river reservoir, where the abundance decreases because of the predominance of washout effects. For both reservoirs, the upstream zone is more distinctive. In addition, in the smaller reservoir the influence of the input from tributaries is stronger (turbid waters). Richness did not differ significantly among seasons, but abundance was higher in the run-of-river reservoir during summer. © 2012 Springer Science+Business Media Dordrecht.

Relaciones entre los rotíferos, copépodos planctónicos ciclopoides y la calidad del agua en dos embalses Brasileños

Planktonic rotifers and cyclopoid copepods were studied in two reservoirs of different trophic states (eutrophic and oligo/mesoeutrophic) in the south of Brazil. During a year, monthly samplings were carried out in three stations in each reservoir. Species richness, frequency and abundance were used to find out useful and indicatives trends of water quality based on these organisms, reinforced by literature data. Species that showed higher differences between reservoirs were chosen. For Rotifera, richness, frequency and abundance of Brachionus were higher in the eutrophic reservoir, but Plationus patulus occurred only in the oligo/mesotrophic reservoir. For copepods, Tropocyclops prasinus dominated in the eutrophic reservoir, but Thermocyclops decipiens, T. minutus, T. inversus and Microcyclops anceps were dominants in the oligo/mesotrophic reservoir. In the canonical correspondence analysis, these species were indicators of the trophic state and were related with chlorophyll-a, total phytoplankton and total phosphorus. The use of these species can be efficient in the studied regions (subtropical/temperate), but comparing with other Brazilian reservoirs of tropical climate, the results could be different. Despite the dominance of T. decipiens over T. minutus, T. inversus has been widely used in Brazil as an indicator of eutrophic waters; in those cases of excessive eutrophication, other species, more rustic, commonly dominate. In the present study, Thermocyclops was dominant in the oligo/mesotrophic reservoir. The dominance of Brachionus for rotifers and Tropocyclops prasinus and Acanthocyclops robustus for copepods were indicative of eutrophic conditions.

Sudden change of quantum discord for a system of two qubits

It is known that quantum discord might experience a sudden transition in its dynamics when calculated for certain Bell-diagonal states (BDS) that are in interaction with their surroundings. We examine this phenomenon, known as the sudden change of quantum discord, considering the case of two qubits independently interacting with dephasing reservoirs. We first demonstrate that, for a class of initial states which can be chosen arbitrarily close to BDS, the transition is in fact not sudden, although it might numerically appear so if not studied carefully. Then, we provide an extension of this discussion covering the X-shaped density matrices. Our findings suggest that the transition of quantum discord might be sudden only for an highly idealized zero-measure subset of states within the set of all possible initial conditions of two qubits. © 2013 American Physical Society.

Prevalência sorológica e molecular de Babesia bovis e Babesia bigemina em búfalos (Bubalus bubalis) na Ilha de Marajó, Pará

The aim of the study was to estimate the prevalence of Babesia bovis and Babesia bigemina in water buffaloes of the Marajó Island, State of Pará, Brazil. We used an indirectenzyme- linked immunosorbent assay (iELISA), with total antigen containing proteins outer surface, and polymerase chain reaction (qPCR), involving the use of SYBR Green based on amplification of a small fragment of the cytochrome b gene. The prevalence of positive animals in iELISA to B. bovis B. bigemina and mixed infection was 24.87% (199/800), 20.75% (166/800) and 18.75% (150/800), respectively. Using the PCR, the presence of B. bovis wasdetected in 15% (18/199) and B. bigemina in 16% (19/199) of animals, and of these, 58% (11/19) presented co-infected by the two agents. The results show a low prevalence of antibodies anti-B. bovis and anti-B. bigemina in water buffaloes from Marajó Island. However, it was observed that the agents of bovine babesiosis circulate in buffaloes, and these may act as reservoirs.

Frequency of different human mollicutes species in the mucosa of the oropharynx, conjunctiva, and genitalia of free-ranging and captive capuchin monkeys (Cebus spp.)

This study is the first to evaluate the occurrence of several Mollicutes species in Brazilian capuchin monkeys (Cebus spp.). Mollicutes were detected by culture and polymerase chain reaction (PCR) in samples of the oropharyngeal, conjuctiva, and genital mucosae of 58 monkeys. In the oropharynx, Mollicutes in general (generic PCR to the Class), and those of the genus Ureaplasma (genus PCR), were detected in 72.4% and 43.0% of the samples, respectively. The identified species in this site included: Mycoplasma arginini (43.1%), M. salivarium (41.4%), and M. pneumoniae (19.0%). Both Ureaplasma and Mycoplasma are genera of the order Mycoplasmatales. In the preputial/vaginal mucosa, PCR detected Mollicutes in general in 27.58% of the samples, the genus Ureaplasma in 32.7%, the species M. arginini in 8.6%, and Acholeplasma laidlawii of the order Acholeplasmatales in 1.7% In the conjunctiva, Mollicutes in general were detected in 29.3% of the samples, with 1.7% being identified as A. laidlawii. Culturing was difficult due to contamination, but two isolates were successfully obtained. The Mollicutes species of this study provided new insights into these bacteria in Brazilian Cebus. Studies are lacking of the actual risk of Mollicutes infection or the frequency at which primates serve as permanent or temporary reservoirs for Mollicutes. In the present study, the samples were collected from monkeys without clinical signs of infection. The mere presence of Mollicutes, particularly those also found in humans, nevertheless signals a need for studies to evaluate the impact of these microorganisms on the health of non-human primates (NHPs) and the possibility of cross-species transmission between NHPs and humans. © 2013 Wiley Periodicals, Inc.

CD95 (FAS) and CD178 (FASL) induce the apoptosis of CD4+ and CD8+ cells isolated from the peripheral blood and spleen of dogs naturally infected with Leishmania spp

Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion. © 2013 Elsevier B.V.