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Sodium alginate (ALG) and sodium carboxymethyl cellulose (CMC) are two polysaccharides that have a wide range of applications, which could lead to accidental pollution of the environment, making the assessment of their potential ecotoxicity imperative. The present study assesses the effects of ALG and CMC on the growth response of common duckweed (Lemna minor L.). The results emphasize that both polysaccharides can be classified as practically nontoxic based on their EC50 values, with ALG having a relatively higher toxicity compared to CMC. It was also observed that high doses of 1, 5 and 10 mg mL-1 of the two polysaccharides produced growth inhibitory effects against common duckweed. The toxicity of biopolymers against common duckweed, measured as EC50 values, seems to be correlated to the hydrophobicity of the monomers building the polymer. The EC50 values increase linearly with increasing water solubility (log S) values and decrease linearly with the lipophilicity (log P) values.

First-order sinking cave streams experience considerable hydrological variability, including spates and periods of base-flow during dry seasons. Early-summer flooding on a first-order stream sinking in Ciur-Ponor Cave (Romania) represented a suitable opportunity to test the response of the macroinvertebrate community and of basal food resources quantity and diversity to such a disturbance event. The invertebrate community and basal resources (i.e., woody debris, leaves, fine particulate organic matter and epilithon) were collected from three sampling sites, before and after the flood. The sampling strategy followed an up-downstream gradient of both species diversity and quantity of allochtonous organic matter decrease as the stream flows through the cave. From each sampling site, ten replicates of both the benthic community and basal resources (detritus and epilithon) were taken. Outside the cave, the spate reduced the invertebrate community density, instant secondary production, complexity and stability (measured as eco-exergy and specific eco-exergy). The epigean section of the stream is populated mainly by taxa characteristic of karst headwaters prone to floods that usually recolonize the streambed rapidly from adjacent habitats. This effect was corroborated with a subsequent increase of both the mass of fine particulate organic matter and of invertebrate density within the cave, following the aftermath of the flood. In the river stretch situated close to the entrance (100 m), where the flood carried both live and dead organic matter, the stability index showed that the complexity of the community was not severely disturbed, despite the high influx of surface-dwelling taxa and temporary increase in species richness. Further downstream, in the third sampling site (400 m from entrance), all measured endpoints indicated a change in community stability, suggesting that local spates can act as rejuvenating drivers in shaping the invertebrate community structure and functioning. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the values of some gravimetric parameters on aboveground parts of wheat. The research was conducted on the Ciprian cultivar. The experimental field was located at the Didactic Station from BUASMV Timisoara. Here the soil can be characterized as a slightly gleized cambic chernozem. The application of fertilizing substances is important due to the fact that it determines qualitative and quantitative changes in crops. Nitrogen is the most used fertilizer globally, due to the fact that it is essential in growth and development. A higher grain yield is assured after the application of ammonium nitrate. For this experiment, five experimental N doses were used: 0, 50, 100, 150 and 200 kg ammonium nitrate ha-1, respectively. The research was realized on the aerial parts of wheat plants. The investigated indices included fresh and dry weights, but also ash content and initial water quantity. The results were analyzed and processed with PAST Software v3. Values lower than 0.05 were considered significant. All the investigated parameters presented the lowest values for N 0 probes and the highest values for N 200 probes, in both periods. Levene's test showed that the values of all parameters for periods 1 and 2 were heterogeneous. Welch F test showed that the data are significantly different. [ABSTRACT FROM AUTHOR]

Mycotoxins are considered to be natural substances produced by fungi, infecting cereals and other agricultural products. The study was conducted on 20 male Sprague-Dowley rats which received feed with known concentration of DON. The animals were divided in 4 groups: Group I - control group, group II - 3 mg//Kgc DON, group III - 5 mg/Kgc DON, group IV - 9 mg/Kgc DON. The blood samples were taken and the main components of bloods were analyzed: erythrocytes, platelets, leucocytes, Ht. (hematocrit), Hb. (concentration hemoglobin). Variations of blood parameters give information regarding the influence of DON on functionality of cardiovascular and excretory system. Administration of DON contaminated feeds determined at Sprague-Dowley rats a decrease of erythrocytes and platelets with each increasing dose (p < 0.05), a decrease of hematocrit and concentration of hemoglobin and no significant changes (p > 0.05) were observed regarding the number of leucocytes. [ABSTRACT FROM AUTHOR]

The aim of our study was to determine the concentrations of Cladosporium, Alternaria and Stemphylium conidia in four urban areas in Romania: Brasov, Bucharest, Craiova and Timisoara. The sites differed in habitat characteristics, such as vegetation and microclimate. Airborne spores sampling was carried out in these cities by employing volumetric sampling. The samplings with the Lanzoni sampler were conducted in 2005. Spores were identified at the genus level only. Alternaria and Cladosporium have been identified as the most abundant and frequent aeroallergens in our cities. The totals of airborne spores recorded in this study show a considerable variation. The higher fungal spore concentrations occur in Bucharest and Craiova. The recorded levels of airborne spores in Bucharest and Craiova were close the concentrations that are accepted as threshold levels for provocation of clinical responses. The diurnal periodicity of aerial conidia showed a peak around midday and low counts in the dark. The present study will contribute to our knowledge of airborne spores in Romania. [ABSTRACT FROM AUTHOR]