Evaluation of the efficiency of three different solvent systems to extract triterpene saponins from roots of Panax quinquefolius using high-performance liquid chromatography

Despite the wide availability of liquid herbal extracts using mixtures of alcohol, glycerin, and water, or glycerin and water as solvents, no data on the chemical composition of such extracts is readily available. In this study, the amount and the stability of the major saponins in Panax quinquefolius root extracts, made either with 50% (v/v) aqueous ethanol, a mixture (v/v/v) of 20% ethanol, 40% glycerin, and 40% water, or with 65% (v/v) aqueous glycerin, were evaluated by HPLC-UV analysis. The amount of total saponins was highest in the 50% aqueous ethanol extract (61.7 +/- 0.1 mg/g dry root), although similar to the ethanol-glycerin-water extract (59.4 +/- 0.5 mg/g dry root). Saponins were significantly lower in the 65% aqueous glycerin extract (51.5 +/- 0.2 mg/g dry root). Interestingly, the amounts of individual saponins were quite variable depending on the solvent. This is in part due to enzymatic cleavage of ginsenosides in the glycerin containing extracts during the maceration process. Storage of the extracts at 25 degrees C over the period of a year led to a 13-15% loss of saponins with all three types of extractions.     

Soil moisture is the major factor influencing microbial community structure and enzyme activities across seven biogeoclimatic zones in western Canada

Although soil microorganisms play a central role in the soil processes that determine nutrient availability and productivity of forest ecosystems, we are only beginning to understand how microbial communities are shaped by environmental factors and how the structure and function of soil microbial communities in turn influence rates of key soil processes. Here we compare the structure and function of soil microbial communities in seven mature, undisturbed forest types across a range of regional climates in British Columbia and Alberta, and examine the variation in community composition within forest types. We collected the forest floor fermentation (F) and humus (H) layers and upper 10 cm of mineral soil at 3 sites in each of seven forest types (corresponding to seven Biogeoclimatic zones) in both spring and summer. Phospholipid fatty acid analysis was used to investigate the structure of soil microbial communities and total soil microbial biomass; potential activities of extra-cellular enzymes indicated the functional potential of the soil microbial community in each layer at each site.Multivariate analysis indicated that both structure and enzyme activities of soil microbial communities differed among the forest types, and significantly separated along the regional climate gradient, despite high local variation. Soil moisture and organic matter contents were most closely related to microbial community characteristics. Forests in the Ponderosa Pine and Mountain Hemlock zones were distinct from other forests and from each other when comparing potential enzyme activities and had the most extreme moisture and temperature values. Forest floors from the hot and dry Ponderosa Pine forests were associated with enzymes characteristic of water-stress and high concentrations of phenols and other recalcitrant compounds. The wet and cold Mountain Hemlock forests were associated with low enzyme activity.An influence of tree species was apparent at the three sites within the Coastal Western Hemlock zone; high bacterial:fungal biomass ratios were found under western redcedar (Thuja plicata) which also had high pH and base-cation levels, and under Douglas-fir (Pseudotsuga menziesii), which had high N availability. Potential activities enzymes differed among soil layers: potential activities of phenol oxidase and peroxidase were highest in mineral soil, whereas phosphatase, betaglucosidase, NAGase, sulfatase, xylosidase and cellobiohydrolase were highest in the forest floors.     

Aetiology of garlic rot,an emerging disease in France

The incidence of garlic rot has constantly increased in France since the early 2000s. To set up an efficient method of garlic protection against this disease, we have clarified its aetiology. This was achieved by surveying garlic from the two main French basins of garlic production over 3 years. Fungi were isolated from 5,493 garlic cloves belonging to pink, purple, and white garlic types. Sequencing of the translation elongation factor 1α gene of 1,171 strains revealed that 94% of the strains belonged to the species Fusarium proliferatum and 6% belonged to F. oxysporum. The pathogenicity of both species on garlic was confirmed by artificial inoculations and reisolations. There was significantly more F. oxysporum in garlic cloves with symptoms coming from the southeast basin (9.44%) than from the southwest basin (2.76%). This study confirms that garlic rot is present in pink, purple, and white types. However, pink type garlic harbours F. oxysporum significantly less frequently (1.59%) than white (9.39%) and purple (7.34%) types. Sequencing of rpb1, rpb2, ITS, and IGS regions of a subsample of strains revealed that there is little genetic diversity in the French population of F. proliferatum.     

Considering evolutionary processes in adaptive forestry

Context

Managing forests under climate change requires adaptation. The adaptive capacity of forest tree populations is huge but not limitless. Integrating evolutionary considerations into adaptive forestry practice will enhance the capacity of managed forests to respond to climate-driven changes.

Aims

Focusing on natural regeneration systems, we propose a general framework that can be used in various and complex local situations by forest managers, in combination with their own expertise, to integrate evolutionary considerations into decision making for the emergence of an evolution-oriented forestry.

Methods

We develop a simple process-based analytical grid, using few processes and parameters, to analyse the impact of forestry practice on the evolution and evolvability of tree populations.

Results

We review qualitative and, whenever possible, quantitative expectations on the intensity of evolutionary drivers in forest trees. Then, we review the effects of actual and potential forestry practice on the evolutionary processes. We illustrate the complexity of interactions in two study cases: the evolutionary consequences for forest trees of biotic interactions and of highly heterogeneous environment.

Conclusion

Evolution-oriented forestry may contribute adapting forests to climate change. It requires combining short-term and long-term objectives. We propose future lines of research and experimentation.     

Building on existing models from human medical education to develop a communication curriculum in veterinary medicine

Communication is a core clinical skill of veterinary medicine and one that needs to be taught and learned to the same degree as other clinical skills. To provide this education and essential expertise, veterinary schools in many countries, especially including North America, the United Kingdom, and Australia, have begun to develop programs and communication curricula. Human medical education, however, has 30 years' experience in developing communication curricula, and is thus an excellent resource upon which veterinary educators can build and shape their own communication programs. This article describes a skills-based communication course that has been successfully implemented for veterinary medical education at Ontario Veterinary College (OVC) and was based on the University of Calgary Faculty of Medicine's well-established program. The Calgary-Cambridge Guides and supporting textbooks provide the scaffolding for teaching, learning, and evaluation in both programs. Resources such as space and materials to support the OVC program were also patterned after Calgary's program. Communication skills, and the methods for teaching and learning them, are equally applicable for the needs of both human medicine and veterinary medicine. The research evidence from human medicine is also very applicable for veterinary medicine and provides it the leverage it needs to move forward. With this extensive base available, veterinary medicine is in a position to move communication skills training forward rapidly.     

Reflection: a critical proficiency essential to the effective development of a high competence in communication

Reflection, or the ability to step back from an experience and consider it critically, in an analytical, non-subjective manner, is an essential aspect of problem solving and decision making, and also of effective communication with clients and colleagues. Reflective practice has been described as the essence of professionalism and is therefore a core professional skill; rarely, however, has it been explicitly taught in veterinary curricula, and it has only a recent history in undergraduate human medical curricula. We describe here two preliminary case studies, one in a veterinary medical education context and the other within a human medical education framework, as examples of approaches to assessing a student's ability for 'reflection.' The case studies also illustrate some of the key principles. Both of the case studies described had as their end goal the enhancement of communication skills through critical reflection. At Monash University, Australia, the majority of students were assessed as being at a level of 'reflection in development.' The students in the Ontario Veterinary College case study showed moderately good use of self-awareness and critical reflection as a basis for modifying and integrating communication skills into practice. While both preliminary case studies point to the fact that students recognize the importance of communication and value the opportunity to practice it, few students in either case study identified the importance of reflection for lifelong learning and professional competence. Opportunities to complete critical reflection exercises in other parts of curricula and outside of communication would likely reinforce its importance as a generic skill. Ongoing scholarly approaches to teaching, learning, and evaluating reflection and self-awareness are needed.