The dissipation of tebuconazole and propiconazole in boronia (Boronia megastigma Nees)

The broad spectrum, systemic fungicides tebuconazole and propiconazole are used to control rust in boronia (Boronia megastigma Nees). Gas chromatography combined with either a benchtop quadrupole mass spectrometer or a high-resolution mass spectrometer allowed for the monitoring of both pesticides in boronia leaves, flowers, and concrete. Field trials were established at two sites to determine the rate of dissipation of tebuconazole and propiconazole in boronia. At site 1, two application rates of 125 and 250 g active ingredient/hectare (ai/ha) tebuconazole were employed. Treatments were repeated 17 days later. At harvest, 286 days after the final application, tebuconazole was detected at levels of 0.06 +/- 0.05 and 0.5 +/- 0.1 [mg/kg +/- standard error, on a dry matter basis (DMB)] in the leaves collected from plots treated with 125 and 250 g ai/ha of tebuconazole, respectively. The oil produced from the flowers collected at the final harvest had residues of tebuconazole at levels of 0.06 +/- 0.03 and 0.10 +/- 0.08 mg/kg for the 125 and 250 g ai/ha application rates, respectively. Two repeat applications of 125 g ai/ha propiconazole were also used at site 1. Residues of propiconazole were detected at 0.09 +/- 0.03 mg/kg (DMB) 286 days after the final application. At site 2, treatments of 125 g ai/ha of tebuconazole were applied twice. At harvest, 279 days after the final application of tebuconazole, residues were recorded at 0.30 +/- 0.09 mg/kg in the leaves (DMB) while the oil produced had 0.20 +/- 0.07 mg/kg.     

Plant nutrients in a degraded soil treated with water treatment sludge and cultivated with grasses and leguminous plants

The objective of this work was to evaluate rates for applications of water treatment sludge (WTS) as a nutrient source for grasses and leguminous plants cropped in a soil degraded by tin mining in the Amazon Region (Natural Forest of Jamari, Rondonia State, Brazil). The treatments consisted of three rates of nitrogen supplied by WTS (100, 150 and 200 mg kg⁻¹ soil), five combinations of plants, two controls (absolute control, without fertilization; and chemical control, soil+lime+chemical fertilizers). WTS modified the contents of macro and micronutrients in the degraded soil, but it was not, as used in the present study, sufficient for the rehabilitation of the degraded area.     

Role of glucose in the maillard browning of maltose and glycine: a radiochemical approach

We followed the contribution of released glucose to the formation of melanoidins in the maltose-glycine reaction by adding (14)C glucose to the maltose-glycine mixture, after it already had undergone some reaction. This approach allowed us to confirm the turnover of glucose in this reaction and hence the role of glucose in forming melanoidins. A comparison of the total amount of glucose converted into the melanoidins with the total concentration of melanoidins formed from maltose and glycine showed that the concentration of melanoidins originating from the released glucose was relatively small in comparison to the total melanoidins concentration. Hence, the parallel glucose-glycine reaction is considered to be only a minor pathway in the formation of maltose-glycine melanoidins. The incorporation of glucose into the nondialyzable melanoidins in the maltose-glycine reaction was in excellent agreement with the amount estimated from a kinetic model for the reaction of maltose with glycine. The rate constants were estimated by nonlinear regression, via multiresponse modeling.     

Microbial and microfaunal community structure in cropping systems with genetically modified plants

Soils from field sites at Foulum (DK), Narbons (FR) and Varois (FR) planted with genetically modified maize expressing either the insecticidal Bacillus thuringiensis protein (Bt) or herbicide tolerance (HT), as described elsewhere in this volume, were analysed for nematodes, protozoa and microbial community structure. These analyses were mirrored in single-species testing and in mesocosm experiments, and were coordinated with field samples taken for microarthropods, enchytraeids and earthworms so allowing for cross-comparison and a better understanding of the results observed in the field. Over the first 2 years of the field experiments (in 2002 and 2003), the effect of Bt-maize was within the normal variation expected in these agricultural systems. Sampling in 2004 and 2005 was expanded to include the effects of tillage (i.e. reduced tillage versus conventional tillage) and also the use of HT-maize. Tillage had major effects regardless of soil type (Varois or Foulum), with reduced-tillage plots having a greater abundance of microfauna and a different microbial community structure (measured both by phospholipid fatty-acid analysis (PLFA) and by community-level physiological profiling (CLPP)) from conventionally tilled plots. Grass, as a contrasting cropping system to maize, also had an effect regardless of soil type and resulted in greater microfaunal abundance and an altered microbial community structure. Differences in crop management, which for the Bt-maize was removal of the insecticide used to control European corn borer and for HT-maize was a change in herbicide formulation, were only tested at single sites. There were differences in microbial community structure (CLPP but not PLFA) and sporadic increases in protozoan abundance under the Bt-crop management. The HT-maize cropping system, which covered a shorter period and only one site, showed little change from the conventional system other than an altered microbial community structure (as measured by PLFA only) at the final harvest. The Bt-trait had a minimal impact, with fewer amoebae at Foulum in May 2003, fewer nematodes at Foulum in May 2004 but more protozoa at Varois in October 2002 and an altered microbial community structure (PLFA) at Foulum in August 2005. These were not persistent effects and could not be distinguished from varietal effects. Based on the field evaluations of microfauna and microorganisms, we conclude that there were no soil ecological consequences for these communities associated with the use of Bt- or HT-maize in place of conventional varieties. Other land management options, such as tillage, crop type and pest management regime, had significantly larger effects on the biology of the soil than the type of maize grown.     

Pathogens as drivers of population declines: The importance of systematic monitoring in great apes and other threatened mammals

Until recently, the focus of great ape behavioural and ecological research has been distinct from the focus of scientists working in medical and veterinary sciences. More scientists are calling for a connection between medical and field research due to recent disease outbreaks in great apes, including Ebola, and indications of cross-transmission of Ebola and other viruses between primates and humans. A major limitation to progress is the lack of information on infectious diseases and their transmission in wild primates. Here, we present examples of successful pathogen detection in wild great apes and describe approaches and techniques that can be used in the field, focusing in particular on investigation of deaths and non-invasive sample collection. This interdisciplinary approach is providing new insights to infectious diseases of great apes and is helping to protect the health of great ape populations. This framework can also be applied to other mammals under threat from infectious diseases, including African wild dogs, seals and Tasmanian devils. In addition to providing benefits for great ape conservation, research that integrates infectious disease with primate ecology provides insights to emerging diseases in humans and the role of disease in primate evolution.     

Agricultural studies of GM maize and the field experimental infrastructure of ECOGEN

Within the ECOGEN project, long-term field experiments with genetically modified maize, Zea mays L. were conducted to study agro-ecological effects on the soil fauna and agro-economic implications of the technology. Here, we describe the study-sites, experimental layout and results of agro-economic relevance. Experiments were conducted during 2002–2005 in Denmark (Foulum), northern France (Varois) and the Midi-Pyrenees region of southern France (Narbons). MON810 Bacillus thuringiensis (Bt)-varieties expressing the Cry1Ab protein, and a T25 glufosinate-ammonium (Basta) tolerant variety expressing the pat-gene encoding phosphinotrinacetyl-transferase were compared with near-isogenic non-Bt varieties, and conventional maize varieties. At Foulum, the maize was harvested for silage. There were no significant differences in yield between Bt-maize and a near-isogenic non-Bt variety, while a small difference in N-concentration of dry matter was detected in 1 year in a range of a measured quality parameters. Similar yield and quality were found in ploughed and reduced tillage treatments in all varieties. At Varois, the maize was harvested at ripeness and no significant differences in grain yield between Bt-maize and near-isogenic non-Bt varieties were found. These results were expected, as only Narbons harbours significant corn-borer populations. At Narbons, the number of Sesamia and Ostrinia corn-borer larvae were significantly lower in the Bt-maize than in a near-isogenic non-Bt variety and for Sesamia even less than in conventional varieties sprayed with pesticides to control corn-borer infestation. Here, Bt-maize produced a higher grain yield and grain size than a near-isogenic non-Bt variety or allowed a significant reduction in pesticide use. Concentrations of Cry1Ab in the Bt-varieties were sufficient to effectively control corn-borer larvae. In soil, Cry1Ab was close to the limit of detection and the protein did not accumulate in the soil year on year.     

Integration of TGF-beta and Ras/MAPK signaling through p53 phosphorylation

During development and tissue homeostasis, cells must integrate different signals. We investigated how cell behavior is controlled by the combined activity of transforming growth factor-beta (TGF-beta) and receptor tyrosine kinase (RTK) signaling, whose integration mechanism is unknown. We find that RTK/Ras/MAPK (mitogen-activated protein kinase) activity induces p53 N-terminal phosphorylation, enabling the interaction of p53 with the TGF-beta-activated Smads. This mechanism confines mesoderm specification in Xenopus embryos and promotes TGF-beta cytostasis in human cells. These data indicate a mechanism to allow extracellular cues to specify the TGF-beta gene-expression program.     

Prevention of organ allograft rejection by a specific Janus kinase 3 inhibitor

Because of its requirement for signaling by multiple cytokines, Janus kinase 3 (JAK3) is an excellent target for clinical immunosuppression. We report the development of a specific, orally active inhibitor of JAK3, CP-690,550, that significantly prolonged survival in a murine model of heart transplantation and in cynomolgus monkeys receiving kidney transplants. CP-690,550 treatment was not associated with hypertension, hyperlipidemia, or lymphoproliferative disease. On the basis of these preclinical results, we believe JAK3 blockade by CP-690,550 has potential for therapeutically desirable immunosuppression in human organ transplantation and in other clinical settings.     

Critical roles for Rac1 and Rac2 GTPases in B cell development and signaling

The Rac1 guanosine triphosphatase (GTPase) has been implicated in multiple cellular functions, including actin dynamics, proliferation, apoptosis, adhesion, and migration resulting from signaling by multiple receptors, including the B cell antigen receptor (BCR). We used conditional gene targeting to generate mice with specific Rac1 deficiency in the B cell lineage. In the absence of both Rac1 and the highly related Rac2, B cell development was almost completely blocked. Both GTPases were required to transduce BCR signals leading to proliferation, survival and up-regulation of BAFF-R, a receptor for BAFF, a key survival molecule required for B cell development and maintenance.