The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog.

(79)Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO3(2-), is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (Kd) values of selenite decreased as a function of sampling depth and highest Kd values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the Kd values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH.

Factors affecting the sorption of cesium in a nutrient-poor boreal bog.

(135)Cs is among the most important radionuclides in the long-term safety assessments of spent nuclear fuel, due to its long half-life of 2.3 My and large inventory in spent nuclear fuel. Batch sorption experiments were conducted to evaluate the sorption behavior of radiocesium ((134)Cs) in the surface moss, peat, gyttja, and clay layers of 7-m-deep profiles taken from a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of radiocesium increased as a function of sampling depth. The highest Kd values, with a geometric mean of 3200 L/kg dry weight (DW), were observed in the bottom clay layer and the lowest in the 0.5-1.0 m peat layer (50 L/kg DW). The maximum sorption in all studied layers was observed at a pH between 7 and 9.5. The in situ Kd values of (133)Cs in surface Sphagnum moss, peat and gyttja samples were one order of magnitude higher than the Kd values obtained using the batch method. The highest in situ Kd values (9040 L/kg DW) were recorded for the surface moss layer. The sterilization of fresh surface moss, peat, gyttja and clay samples decreased the sorption of radiocesium by 38%, although the difference was not statistically significant. However, bacteria belonging to the genera Pseudomonas, Paenibacillus, Rhodococcus and Burkholderia isolated from the bog were found to remove radiocesium from the solution under laboratory conditions. The highest biosorption was observed for Paenibacillus sp. V0-1-LW and Pseudomonas sp. PS-0-L isolates. When isolated bacteria were added to sterilized bog samples, the removal of radiocesium from the solution increased by an average of 50% compared to the removal recorded for pure sterilized peat. Our results demonstrate that the sorption of radiocesium in the bog environment is dependent on pH and the type of the bog layer and that common environmental bacteria prevailing in the bog can remove cesium from the solution phase.

Sorption of radioiodide in an acidic, nutrient-poor boreal bog: insights into the microbial impact.

Batch sorption experiments were conducted to evaluate the sorption behaviour of iodide and the microbial impact on iodide sorption in the surface moss, subsurface peat, gyttja, and clay layers of a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of iodide decreased as a function of sampling depth. The highest Kd values, 4800 L/Kg dry weight (DW) (geometric mean), were observed in the fresh surface moss and the lowest in the bottom clay (geometric mean 90 mL/g DW). In the surface moss, peat and gyttja layers, which have a high organic matter content (on average 97%), maximum sorption was observed at a pH between ∼ 4 and 5 and in the clay layer at pH 2. The Kd values were significantly lower in sterilized samples, being 20-fold lower than the values found for the unsterilized samples. In addition, the recolonization of sterilized samples with a microbial population from the fresh samples restored the sorption capacity of surface moss, peat and gyttja samples, indicating that the decrease in the sorption was due to the destruction of microbes and supporting the hypothesis that microbes are necessary for the incorporation of iodide into the organic matter. Anoxic conditions reduced the sorption of iodide in fresh, untreated samples, similarly to the effect of sterilization, which supports the hypothesis that iodide is oxidized into I2/HIO before incorporation into the organic matter. Furthermore, the Kd values positively correlated with peroxidase activity in surface moss, subsurface peat and gyttja layers at +20 °C, and with the bacterial cell counts obtained from plate count agar at +4 °C. Our results demonstrate the importance of viable microbes for the sorption of iodide in the bog environment, having a high organic matter content and a low pH.

Estaquia de Cuphea calophylla subsp. mesostemon (Koehne) Lourteig (Lythraceae) / Cutting of Cuphea calophylla subsp. mesostemon (Koehne) Lourteig (Lythraceae)

As informações a respeito da propagação de Cuphea calophylla subsp. mesostemon (Koehne) Lourteig (Lythraceae) são escassas. As técnicas de propagação podem subsidiar o manejo, fornecendo alternativa para produtores de plantas medicinais e evitando a coleta indiscriminada. O presente trabalho teve como objetivo verificar o efeito de diferentes tipos de estaca, tamanhos e área foliar no enraizamento de estacas semilenhosas. As estacas foram obtidas a partir de plantas espontâneas coletadas na Estação Experimental do Canguiri da Universidade Federal do Paraná (UFPR), localizada em Pinhais - PR. Os experimentos com estaquia foram conduzidos em casa-de-vegetação. O delineamento foi inteiramente casualizado com cinco repetições e 24 estacas por parcela, para todos os experimentos. As estacas obtidas de ramos vegetativos apresentaram maior porcentagem de brotação e massa seca de raízes por estaca em relação àquelas obtidas de ramos reprodutivos, especialmente, as estacas obtidas da parte basal dos ramos vegetativos. As estacas preparadas com 10 e 15 cm de comprimento apresentaram maior número de brotos e maior massa seca de raízes por estaca, em relação às preparadas com 5 cm. As estacas com 3 e 4 pares de folhas apresentaram maior altura, incremento de altura, massa seca de raízes e de brotos por estaca, em relação aos tratamentos com 1 e 2 pares de folhas. Os resultados de propagação vegetativa apontam a estaquia como uma técnica viável para a multiplicação da espécie.

Information about the propagation of Cuphea calophylla subsp. mesostemon (Koehne) Lourteig (Lythraceae) is scarce. Propagation techniques may support its management, providing an alternative for medicinal plant producers and avoiding indiscriminate harvests. This study aimed to investigate the effect of different types, sizes and leaf areas of semi-woody cuttings on their rooting. Cuttings were obtained from weeds harvested at the Canguiri Experimental Station of the Paraná Federal University (UFPR), Pinhais Municipality, Paraná State, Brazil. Experiments were carried out in a greenhouse. Experimental design was completely randomized, with five replicates and 24 cuttings per plot. Cuttings obtained from vegetative branches had higher sprouting percentage and root dry matter per cutting relative to those obtained from reproductive branches, especially cuttings obtained from the basal region of vegetative branches. Cuttings prepared with 10 and 15 cm length had larger number of sprouts and higher root dry matter per cutting relative to those prepared with 5 cm. Cuttings presenting 3 and 4 leaf pairs had greater height, increase in height, and root and sprout dry matter per cutting relative to those presenting 1 and 2 leaf pairs. The results regarding vegetative propagation indicate cutting as a viable technique for the multiplication of this species.

(137)Cs, (239,240)Pu and (241)Am in bottom sediments and surface water of Lake Päijänne, Finland.

The concentrations and vertical distribution of (239,240)Pu, (241)Am and (137)Cs in the bottom sediments and water samples of Lake Päijänne were investigated. This lake is important, since the Päijänne area received a significant deposition from the Chernobyl fallout. Furthermore Lake Päijänne is the raw water source for the Helsinki metropolitan area. In addition no previous data on the distribution of plutonium and americium in the sediment profiles of Lake Päijänne exist. Only data covering the surface layer (0-1cm) of the sediments are previously available. In the sediments the average total activities were 45+/-15Bq/m(2) and 20+/-7Bq/m(2) for (239,240)Pu and (241)Am, respectively. The average (241)Am/(239,240)Pu ratio was 0.45+/-0.14. The (241)Am/(239,240)Pu ratio is lowest in the surface layer of the sediments and increases as a function of depth. The (238)Pu/(239,240)Pu ratio of the sediment samples varied between 0.012+/-0.025 and 0.162+/-0.079, decreasing as a function of depth. The average activity in water was 4.9+/-0.9mBq/m(3) and 4.1+/-0.2mBq/m(3) for (239,240)Pu and (241)Am, respectively. The (241)Am/(239,240)Pu ratio of water samples was 0.82+/-0.17. (239,240)Pu originating from the Chernobyl fallout calculated from the average total activities covers approximately 1.95+/-0.01% of the total (239,240)Pu activity in the bottom sediments. The average total (137)Cs activity of sediment profiles was 100+/-15kBq/m(2) and 19.3+/-1.4Bq/m(3) in water samples.

Association between testicular microlithiasis and primary malignancy of the testis: our experience and review of the literature.

PURPOSE: The aims of this study were to evaluate the association of testicular microlithiasis with testicular neoplasm, to assess the accuracy of ultrasonography (US) in comparison with histology in detecting microlithiasis, and to identify the prevalent cytohistological features that accompany testicular cancer. MATERIALS AND METHODS: Between 2004 and 2005, 14 patients were referred to us for US examination, 13 of whom underwent surgery for testicular cancer. Their age ranged from 19 to 43 years, except for one patient aged 60. US findings and histological examination were compared to assess the accuracy of US in detecting microlithiasis associated with testicular cancer. RESULTS: In two patients (15.3%), microlithiasis had been detected in a previous US examination, and two patients (15.3%) had altered sperm function. At US examination, testicular cancer was associated with microlithiasis in seven out of 13 patients (53.8%) (the distribution pattern of microlithiasis was intranodular in two, perinodular in two and both intra-and perinodular in three), and colour-Doppler US showed perinodular and intranodular vascularity. Histological evaluation identified nine seminomas, two mixed germ-cell tumours, one embryonal carcinoma, one yolk-sac tumour and one benign Sertoli-cell tumour. In nine (69.2%) patients, microlithiasis was confirmed at histologic evaluation, and its distribution was intranodular in two, perinodular in five and both intra-and perinodular in two. Tubular hyalinisation was demonstrated in 12 out of 13 patients (92.3%). CONCLUSIONS: Testicular microlithiasis and poor sperm function represent risk factors for testicular cancer: in our study, 30.6% of the patients who developed cancer presented these features. At US examination, testicular microlithiasis is often associated with testicular cancer (53.8%). A high accuracy has been demonstrated for US in detecting microlithiasis (53.8%) compared with histological evaluation (69.2%). At histology, tubular hyalinisation (92.3% of cases) is, with testicular microlithiasis, the most frequent finding in the parenchyma adjacent to testicular cancer.