Responses by earthworms to reduced tillage in herbicide tolerant maize and Bt maize cropping systems

Genetically modified (GM) crops may affect earthworms either directly through the plant, its root exudates and litter, or indirectly through the agricultural management changes that are associated with GM plant production. In order to investigate such possible effects, we established two field studies of Bacillus thuringiensis (Bt) maize and a glufosinate ammonium tolerant maize and included a reduced tillage (RT) treatment and a conventional tillage (CT) treatment as examples of a likely concomitant change in the agricultural practise. At a French study site at Varois, (Bourgogne), a field grown with the Bt-toxin producing transgenic maize line MON810 was studied for 1 year. At a Danish study site, Foulum (Jutland), 1 year of Bt maize was followed by 2 years of herbicide tolerant (HT) maize. At the French study site, the most prominent effects observed were due to the tillage method where RT significantly reduced the earthworm populations to levels about half of CT. At the Danish study site effects of CT complied with known reduction of anecic earthworms due to this technique and likewise effects of RT were observed for endogeic earthworms. Earthworm populations were diminished with the HT crop, probably due to exposure to the herbicide Basta^® during the two consecutive autumn seasons. This study confirms the importance of including the tillage techniques and pesticide usage when evaluating the environmental effects of new agricultural technologies.     

Bioavailability and antioxidant effects of orange juice components in humans

Seven healthy females and six males consumed daily 256 mg of vitamin C, 271 mg of flavanones (mainly as glycosides), 6 mg of carotenoids (mainly xanthophylls and cryptoxanthins), and 0.16 mg of folate by incorporation of daily three times 236 mL of not from concentrate orange juice (OJ) into their habitual diet. At the end of 3 weeks, mean vitamin C, folate, carotenoid, and flavanone plasma concentrations increased significantly relative to baseline by 59% (p < 0.001), 46% (p = 0.018), and 22% (p < 0.001), and 8-fold (p = 0.045), respectively. Flavanones were excreted in urine 9-fold more at the end of the intervention (p = 0.01) but returned to baseline 2 days after study completion. After the 3 week intervention, plasma concentrations of vitamins A and E did not change. 8-Hydroxydeoxyguanosine in white blood cells declined by 16% (p = 0.38; n = 11), and in individuals with high baseline concentrations by 29% (p = 0.36; n = 7), respectively. Low-density lipoprotein (LDL)-/high-density lipoprotein (HDL)-cholesterol ratios decreased but cholesterol (HDL, LDL, total) and thiobarbituric acid reactive substance plasma concentrations did not change significantly. We conclude from this pilot study that OJ is an excellent food source to enhance circulating concentrations of valuable hydrophilic as well as lipophilic phytochemicals.     

Cadmium in Fagus sylvatica L. trees and seedlings: Leaching,uptake and interconnection with transpiration

Most of the airborne Cd-polluted particles which eventually precipitate in forest regions remain on the surface of the tree leaves and do not penetrate into the plants' live tissues. Such pollutions can be removed from the leaves by cation exchange or can be washed off with water of low pH. Acid rains and acid soils have contributed very much to the solubilization of Cd and to its transformation into an available ionic form which is later absorbed by tree roots. ^115mCd uptake by young beech trees (Fagus sylvatica L.) seems to be positively correlated with the concentrations of the applied solutions as well as with the duration of the exposure. Low environmental pH increases the rate of ^115mCd uptake. High or low transpiration had no apparent effect on root absorption of Cd, but exposure of beech trees to a Cd(NO₃)₂ solution reduced their rates of transpiration after very few days of treatment.     

Formation and subdivision of deformation structures during plastic deformation

During plastic deformation of metals and alloys, dislocations arrange in ordered patterns. How and when these self-organization processes take place have remained elusive, because in situ observations have not been feasible. We present an x-ray diffraction method that provided data on the dynamics of individual, deeply embedded dislocation structures. During tensile deformation of pure copper, dislocation-free regions were identified. They showed an unexpected intermittent dynamics, for example, appearing and disappearing with proceeding deformation and even displaying transient splitting behavior. Insight into these processes is relevant for an understanding of the strength and work-hardening of deformed materials.     

Haemorrhagic pneumonia in sled dogs caused by Streptococcus equi subsp. zooepidemicus - one fatality and two full recoveries: a case report

In spite of yearly vaccination, outbreaks of canine infectious respiratory disease are periodically seen amongst domestic dogs. These infections compromise host defense mechanisms, and, when combined with other stressful events, allow opportunistic pathogens like Streptococcus equi subsp. zooepidemicus to create serious disease. Early recognition and treatment are tremendously important for a successful outcome in these cases. A polyvalent vaccine was given to 22 racing dogs three days after a competition, followed by two days of rest, and then the dogs were returned to regular training. Coughing was noticed among the dogs four days after immunisation. Three days after this outbreak one of the dogs was unusually silent and was found dead the next morning. Simultaneously two other dogs developed haemorrhagic expectorate, depression and dyspnea and were brought in to the veterinary hospital. Streptococcus equi subsp. zooepidemicus was isolated in pure culture from all three cases. They were treated and rehabilitated successfully, and won a sledge race three months later. This paper discusses the necropsy results, treatment regime, rehabilitation and the chronology of vaccination, stressful events and disease.     

Comparison of the Q-fever complement fixation test and two commercial enzyme-linked immunosorbent assays for the detection of serum antibodies against Coxiella burnetii (Q-fever) in ruminants: Recommendations for use of serological tests on imported animals in New Zealand

Abstract

AIM: To make valid recommendations on the use of serological test methods for the detection of serum antibodies in ruminants against Coxiella burnetii (Q-fever), by comparing the performance of the complement fixation test (CFT) and two ELISA, and by identifying reasons for discrepancies between the test methods.

METHODS: A total of 73 serum samples from infected cattle, 69 from infected goats, and 100 samples from non-infected cattle and 57 samples from non-infected sheep, as well as 95 samples from infected cattle herds (mix of seropositive and seronegative samples), were tested using the CFT, the IDEXX ELISA (I-ELISA) and the Pourquier ELISA (P-ELISA). A mixed panel of 12 serum samples from sheep from inter-laboratory proficiency testing (proficiency panel) was also tested using the CFT and both ELISA, and further investigated using IgG- and IgM-specific ELISA.

RESULTS: Generally, the two commercial ELISA were more sensitive than the CFT for the detection of infected ruminants. Good agreement between ELISA for positive and negative results was found for samples from the infected herd, while results for the positive panels varied between the two ELISA. For the total of the positive serum panels, the I-ELISA detected 95% of samples as positive or suspicious, while the P-ELISA detected only 81%. In the P-ELISA, more samples were considered suspicious (18%) than in the I-ELISA (14%). All sera from noninfected sheep and cattle tested negative in the serological test methods employed, except for one positive sample from a sheep in the P-ELISA. Further investigation revealed that a CFT-positive but ELISA-negative result was due to high IgM and low IgG reactivity.

CONCLUSIONS: The two commercial ELISA were more sensitive than the CFT in all panels from infected ruminants. However, they could only detect IgG. The I-ELISA should be the serological test method of choice for cattle, sheep and goats for import testing of animals into New Zealand because it was more sensitive than the P-ELISA and was equally specific to the PELISA and the CFT. For other animal species, such as deer and camelids, the CFT should still be used since none of the ELISA has been evaluated for these species. This study has shown that the two commercial ELISA will detect the majority of infected ruminants but may miss animals that have not developed an IgG response.     

Population performance of collembolans feeding on soil fungi from different ecological niches

The potential reproductive value of arbuscular mycorrhizal fungi (Glomus intraradices and Glomus invermaium), root pathogenic fungi (Rhizoctonia solani and Fusarium culmorum) and saprotrophic fungi (Penicillium hordei and Trichoderma harzianum) were examined for the collembolans Folsomia candida Willem and Folsomia fimetaria L. Dried baker's yeast (Saccharomyces cerevisiae) was used as a reference standard food in laboratory cultures. Collembolan performance was determined as final size, fecundity and population growth rate after when fed the fungal food sources for 31 days. The mycorrhizal fungi gave the least growth and fecundity compared with the other fungi, but G. intraradices gave good fecundity for F. candida. In terms of growth, Baker's yeast was a high-quality food for both adults and juveniles of both species, but it was a poorer food in terms of fecundity of F. candida. Preference of the fungi in all possible pairwise combinations showed that although F. fimetaria did not perform well on Glomus spp. and F. candida did not grow well on Glomus spp. their preference for these fungi did not reflect this. The highest fecundity was seen with the root pathogen F. culmorum. Different quality indicators such as the C:N ratio of the fungal food sources as well as other biological parameters are discussed in relation to their reproductive value and Collembola preferential feeding.