Impact of deer on temperate forest vegetation and woody debris as protection of forest regeneration against browsing

A 3-year field experiment with paired exclosure (fenced areas, excluding deer) and control plots (unfenced areas, free access to deer), with two treatments with and without woody debris, was carried out at two sites in a temperate forest in eastern France. The aim of the experiment was to assess the effect of browsing by roe deer (Capreolus capreolus) and red deer (Cervus elaphus) on the diversity and richness of plant species and to test the effectiveness of using woody debris to protect seedlings and saplings from deer browsing. In presence of deer, both plant species richness and diversity were reduced the first year of the study, but this negative impact of deer then disappeared after 3 years. Deer browsing mostly affected species composition of plant communities. We observed a decrease in the abundance of preferred species such as Carpinus betulus, Rubus fructicosus, Rubus idaeus, Anemone nemorosa and Epilobium angustifolium, and palatable species such as Acer spp., Carex spp., Festuca spp. and Mycelis muralis, whereas unpalatable species such as Lamium spp., or species particularly resilient to browsing such as grasses (Brachypodium spp. and Luzula spp.) increased in abundance. The use of woody debris as protection against browsing by deer did not limit damage to seedlings and saplings of the main commercially valuable species, Abies alba and Quercus spp. Instead of limiting deer impact, use of woody debris seemed to increase the negative effect of deer browsing on regeneration in control plots relatively to those without protection.     

High-contrast three-dimensional imaging of the Arabidopsis leaf enables the analysis of cell dimensions in the epidermis and mesophyll

Background  

Despite the wide spread application of confocal and multiphoton laser scanning microscopy in plant biology, leaf phenotype assessment still relies on two-dimensional imaging with a limited appreciation of the cells' structural context and an inherent inaccuracy of cell measurements. Here, a successful procedure for the three-dimensional imaging and analysis of plant leaves is presented.     

First Steps Towards an Understanding of a Mode ofCarcinogenic Action for Vanadium Pentoxide

Inhalation of vanadium pentoxide clearly increases the incidence of alveolar/bronchiolar neoplasms in male and female B6C3F1 mice at all concentrations tested (1, 2 or 4 mg/m³), whereas responses in F344/N rats was, at most, ambiguous. While vanadium pentoxide is mutagenic in vitro and possibly in vivo in mice, this does not explain the species or site specificity of the neoplastic response. A nose-only inhalation study was conducted in female B6C3F1 mice (0, 0.25, 1 and 4 mg/m³, 6 h/day for 16 days) to explore histopathological, biochemical (α-tocopherol, glutathione and F2-isoprostane) and genetic (comet assays and 9 specific DNA-oxo-adducts) changes in the lungs. No treatment related histopathology was observed at 0.25 mg/m³. At 1 and 4 mg/m³, exposure-dependent increases were observed in lung weight, alveolar histiocytosis, sub-acute alveolitis and/or granulocytic infiltration and a generally time-dependent increased cell proliferation rate of histiocytes. Glutathione was slightly increased, whereas there were no consistent changes in α-tocopherol or 8-isoprostane F2α. There was no evidence for DNA strand breakage in lung or BAL cells, but there was an increase in 8-oxodGuo DNA lesions that could have been due to vanadium pentoxide induction of the lesions or inhibition of repair of spontaneous lesions. Thus, earlier reports of histopathological changes in the lungs after inhalation of vanadium pentoxide were confirmed, but no evidence has yet emerged for a genotoxic mode of action. Evidence is weak for oxidative stress playing any role in lung carcinogenesis at the lowest effective concentrations of vanadium pentoxide.     

Issues and special features of animal health research

ABSTRACT: In the rapidly changing context of research on animal health, INRA launched a collective discussion on the challenges facing the field, its distinguishing features, and synergies with biomedical research. As has been declared forcibly by the heads of WHO, FAO and OIE, the challenges facing animal health, beyond diseases transmissible to humans, are critically important and involve food security, agriculture economics, and the ensemble of economic activities associated with agriculture. There are in addition issues related to public health (zoonoses, xenobiotics, antimicrobial resistance), the environment, and animal welfare.Animal health research is distinguished by particular methodologies and scientific questions that stem from the specific biological features of domestic species and from animal husbandry practices. It generally does not explore the same scientific questions as research on human biology, even when the same pathogens are being studied, and the discipline is rooted in a very specific agricultural and economic context.Generic and methodological synergies nevertheless exist with biomedical research, particularly with regard to tools and biological models. Certain domestic species furthermore present more functional similarities with humans than laboratory rodents.The singularity of animal health research in relation to biomedical research should be taken into account in the organization, evaluation, and funding of the field through a policy that clearly recognizes the specific issues at stake. At the same time, the One Health approach should facilitate closer collaboration between biomedical and animal health research at the level of research teams and programmes.     

In vitro bile acid binding activity within flour fractions from oat lines with typical and high beta-glucan amounts

Whole flours from four oat lines with different amounts of beta-glucan (4.8-8.1%) were examined for their antioxidant activity and total phenolic and lignin concentrations. These data, along with the beta-glucan percentages, were compared with bile acid (BA) binding. Only the lignin concentrations of the flours significantly (P < 0.01) correlated with the BA binding values. The oat flours also were fractionated into bran, protein concentrate, starch, layer above starch, and soluble beta-glucan (SBG)-free flour, and their BA binding capacities were evaluated. The bran fractions were the only fractions that bound greater BA than did the whole oat flours on dry matter basis. Extraction of the soluble beta-glucan to create the SBG-free flour significantly (P < 0.01) decreased the BA binding of the remaining flour. These data suggest that BA binding of the oat flours involves the synergistic interactions of the oat components, with beta-glucan and lignin (insoluble fiber) having a great impact.     

Facilitated cross-species transmission of prions in extraneural tissue

Prions are infectious pathogens essentially composed of PrP(Sc), an abnormally folded form of the host-encoded prion protein PrP(C). Constrained steric interactions between PrP(Sc) and PrP(C) are thought to provide prions with species specificity and to control cross-species transmission into other host populations, including humans. We compared the ability of brain and lymphoid tissues from ovine and human PrP transgenic mice to replicate foreign, inefficiently transmitted prions. Lymphoid tissue was consistently more permissive than the brain to prions such as those causing chronic wasting disease and bovine spongiform encephalopathy. Furthermore, when the transmission barrier was overcome through strain shifting in the brain, a distinct agent propagated in the spleen, which retained the ability to infect the original host. Thus, prion cross-species transmission efficacy can exhibit a marked tissue dependence.     

The functional structure of ectomycorrhizal communities in an oak forest in central France witnesses ancient Gallo-Roman farming practices

The activities of nutrient-mobilising enzymes secreted by ectomycorrhizas of sessile oak (Quercus petraea) have been measured in 24 plots in a forested area in central France where many rural Gallo-Roman settlements (first to fifth centuries AD) have been discovered. Data have been related with tree growth and soil chemical properties. Although soil near the past settlements is still enriched in N and P, this does not always correspond to the higher productivity of oak trees. However, when this is the case, the ectomycorrhizal community displays higher chitinase, protease and phosphatase activities (involved in N and P mobilisation from soil organic matter). A few specialised ectomycorrhizal fungal species are responsible for this adaptation to the long-lasting modification of soil conditions.     

Causes, diagnostic signs, and the utility of investigations of fever in dogs: 50 cases

This study aimed to determine the distribution of diseases causing fever in dogs in France. Dogs with fever were reviewed and 50 dogs were retrospectively assigned to disease groups. Fever profile and intensity, the time taken to reach a diagnosis, and inflammatory status were compared among groups. Almost half the dogs (48%) were diagnosed with non-infectious inflammatory diseases. No final diagnosis was reached in 14 dogs, 13 of which belonged to owners who did not wish to pursue the investigations. No association was found between disease group and the intensity of fever, fever profile, or serum C-reactive protein concentration. Cytological examinations were most frequently found to be the most important determinant for diagnosis (55.7%). This study confirms the predominance of non-infectious inflammatory diseases as causes of fever. Neither clinical nor biological factors were found to be predictive of disease group.