Acaricidal properties of the essential oil and precocene II obtained from Calea serrata (Asteraceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Calea serrata Less. (Asteraceae), an endemic species of south Brazil known as "quebra-tudo", is used in Afro-Brazilian religious rituals and in folk medicine for treating liver disorders. Phytochemical studies of the n-hexane extract of this plant demonstrated the presence of precocene II, a benzopyran derivative known for its insecticidal activity. The aim of this work was to isolate this benzopyran and determine the chemical composition of the essential oil of C. serrata and further to evaluate the acaricidal activity of the essential oil and precocene II against the larvae of Rhipicephalus (Boophilus) microplus. The LC(99.9) and LC(50) values obtained with the oil, which presents precocene II and sesquiterpenes, were 3.94 μL/mL and 0.28 μL/mL, respectively. For precocene II this values were 4.25mg/mL and 1.78 mg/mL, respectively. The results indicate a synergistic interaction between the components of the oil and precocene II.     

Biodegradation of Soybean Biodiesel Generates Toxic Metabolites in Soil

Water, Air, &; Soil Pollution - Phytoremediation is a cost-effective and relatively cleaner method for remediating contaminated areas using plants. Certain plants, including some sunflower...     

Radiography and computed tomography of the heart and lower respiratory tract in toco toucans (Ramphastos toco)

This study aimed to evaluate normal features of the heart and lower respiratory tract in toco toucans by means of radiography and helical computed tomography (CT) scanner. Fifteen healthy adult toco toucans (Ramphastos toco), 10 females and 5 males, average body mass of 650 g were studied. CT examination as well as right lateral and ventrodorsal radiographic examinations of the coelomic cavity were performed under chemical restraint. Heart, lungs, air sacs, trachea and syrinx were analysed. The mean values of heart length, heart width and thoracic cavity in radiographs were, respectively, 23.76 mm, 25.94 mm and 48.87 mm. In both X-rays and CT scans, the lung parenchyma had honeycomb-like pattern. The topographic areas of the anterior and posterior air sacs were visualized as dark and air-filled spaces in X-rays. On CT evaluation, the air sacs occupied a larger area in the coelomic cavity compared to X-ray. In the lateral radiographic view, the cervical part of the trachea was positioned more ventrally in the transition from cervical to thoracic regions showing a V-shaped appearance. In all CT planes was visible division of the trachea into the right and left main bronchi at the level of 3rd thoracic vertebra. The syrinx was difficult to visualize in X-rays, but on CT it was easily identified in axial slice. In conclusion, the normal features of toco toucan's heart and lower respiratory tract that were determined on X-rays and CT scans are useful to compare with sick toco toucans, as well as other bird species.     

Biodegradation and Phytotoxicity of Biodiesel,Diesel, and Petroleum in Soil

Biogas must be pretreated before its use; thus, both physical and chemical methods have been implemented to remove the fuel’s principal pollutants (CO₂ and H₂S). Additional removal methods that use microorganisms’ biological processes to eliminate pollutants have also emerged. A selection was made from six bacterial isolates to obtain consortia that removed CO₂ and eventually H₂S through the enrichment of cultures and the construction of clone libraries of gene 16S ribosomal DNA (rDNA). The results indicate that the principal differences between consortia were determined in the culture medium. C5 and C6 consortia had photosynthetic biomass 1.42 and 1.52 μg/ml, respectively, and concentration of dissolved CO₂ 100.6 and 99.1 mg/l, respectively. The clone libraries showed that Rhodopseudomonas sp. had percentages 46.6, 42.5, and 86.8 % in C4, C5, and C6, respectively; Xanthobacter sp., 24.5 %, Castellaniella sp., 18 % in C5, and Sphingobium sp., 39.2 % in C4.     

The evolution of weed beet in sugar beet crops

Summary The extent of the weet beet problem in Eastern England is described and the factors to the evolution of weed beet are outlined. Some preliminary experiments designed to distinguish between wild, weed and cultivated populations of beet are described. The response of salt (sodium chloride) solution is a potentially useful discriminating character whereas variation in morphometric characters was not so conclusive. Preliminary results on variation in cytological characters suggest that chiasma frequency is lower in weed than in wild populations and cultivars ofBeta vulgaris. Finally the possible role of crop-related weeds in breeding is discussed.

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Die Evolution der Unkrautrüben in Zuckerrübenbeständen

Zusammenfassung Es wird die Verbreitung des Problems der Unkrautrüben im östlichen England beschrieben und die Faktoren, die die Evolution der Unkrautrübenpopulation beeinflussen, werden umrissen. Einige vorläufige Versuche zur Unterscheidung zwischen Wild-, Unkraut- und kultivierten Populationen werden beschrieben. Die Reaktion auf Salzlösung (Natriumchlorid) zeigte sich als eine brauchbare Trennmethode, während die Variation in der morphometrischen Charakterisierung nicht so überzeugend war. Vorläufige Ergebnisse über die Unterschiede in der cytologischen Charakterisierung weisen darauf hin, daß die Chiasmafrequenz in Unkrautrüben geringer ist, als in Wildpopulationen und Kultursorten vonBeta vulgaris. Abschließend wird die mögliche Bedeutung der den Kulturpflanzen verwandten Unkräuter für die Züchtung diskutiert.

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Beta L. ë

Beta ë , . , , . ( ) , . , ë , Beta vulgaris. , .

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We are deeply impressed by the untimely death of Dr. A. Evans. The editors.     

Soil organic matter pools and carbon-protection mechanisms in aggregate classes influenced by surface liming in a no-till system

The stabilisation of soil organic matter (SOM) is the result of the simultaneous action of three mechanisms: chemical stabilisation, biochemical stabilisation and physical protection. The objectives of this study were (i) to evaluate carbon-protection mechanisms in different SOM pools in soil aggregates and (ii) to identify the association of Ca^2 + with total organic carbon (TOC) under the influence of surface liming in a medium-textured Oxisol in a long-term experiment under no-till system (NTS) in southern Brazil (25° 10′ S, 50° 05′ W). The treatments consisted of application of zero or 6 tons ha^? 1 of dolomitic lime on the soil surface in 1993 and a reapplication of zero or 3 tons ha^? 1 of dolomitic lime in 2000 to plots with or without previous lime application. Soil samples collected at depths of 0–2.5, 2.5–5, 5–10 and 10–20 cm were separated into seven aggregate classes. In each of these classes, TOC, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) were analysed. The 8–19 mm sized aggregates from the 0–2.5 cm layer were assessed by energy-dispersive X-ray spectroscopy (EDS) for the elemental analysis of carbon (C) and calcium (Ca). The liming caused an accumulation of TOC in the aggregates, mainly at a depth of 0–2.5 cm. The aggregates from soils treated with lime had a higher mean weight diameter (MWD) that resulted in the accumulation of TOC, especially in the 8–19 mm aggregate class, that was linear and closely related with C input (R² = 0.99). The proportion of large aggregates in the treatments with lime was closely correlated with the TOC content of the whole sample. The largest dose of lime (9 tons ha^? 1) resulted in higher TOC, POC and MAOC values, mainly in the 8–19 mm aggregate class. The elemental analyses for C and Ca revealed similar spectra between them for the surface-liming treatments in the clay fraction found in the centres of the 8–19 mm aggregates. The surface application of lime to NT fields provided greater stability and protection of the intra-aggregate C, presumably due to Ca^2 + acting as a cationic bridge between OC and the kaolinite in the clay fraction.