Conservation Program Participation and Adaptive Rangeland Decision-Making

This paper analyzes rancher participation in conservation programs in the context of a social-ecological framework for adaptive rangeland decision-making. We argue that conservation programs are best understood as one of many strategies of adaptively managing rangelands in ways that sustain livelihoods and ecosystem services. The framework hypothesizes four categories of variables affecting conservation program participation: operation/operator characteristics, time horizon, social network connections, and social values. Based on a mail survey of California ranchers, multinomial logit models are used to estimate the impact of these variables on different levels of rancher involvement in conservation programs. The findings suggest that ranchers with larger amounts of land, an orientation towards the future, and who are opinion leaders with access to conservation information, are more likely to participate in conservation programs.     

Assessing genetic variation to improve stem straightness in Eucalyptus globulus

Context

Stem straightness is an important trait for growers and processors of Eucalyptus globulus logs for solid-wood products.

Aims

The aims of the study were to determine the extent of genetic variation in stem deviation from straightness in E. globulus and assess the utility of a six-point subjective scoring method as a selection criterion for stem straightness.

Methods

Two E. globulus progeny trials, grown under solid-wood product regimes, were studied. At age 9 years (post-thinning), stem straightness was measured using both image analysis and a six-point subjective scale. Diameter at breast height (DBH; 1.3 m) was measured at both age 5 (pre-thinning) and age 9 years.

Results

Significant additive genetic variation was observed. Strong, positive and significant additive genetic correlations were observed between the stem straightness assessment methods and between DBH at ages 5 and 9 years. Significant positive genetic correlations were shown between subjectively scored stem straightness and DBH at both ages 5 and 9 years.

Conclusion

The six-point subjective scoring method is a cost-effective selection criterion for stem straightness in E. globulus. The image measurement technique may be applied where objective estimates of stem straightness are required, for training purposes and to verify subjective scores.     

Morphological characterization of seeds of three Australian wild Citrus species (Rutaceae): Citrus australasica F. Muell., C. inodora F.M. Bailey and C. garrawayi F.M. Bailey

The comparative morphology of the seeds of three Australian Citrus species, C. australasica C. inodora and C. garrawayi, was studied. Their seed characteristics were broadly similar to those of the cultivated species of the genus, when observed under light and scanning electron microscopy. Citrus garrawayi differed in seed shape (rounded to triangular) and seed coat morphology (i.e., thicker with longer epidermal protrusions) from C. australasica and C. inodora (rounded surface with flat underside in shape). The well-developed minute epidermal protrusions on the seed coat of C. garrawayi were more similar to those in the cultivated species, C. × sinensis and C. × aurantium. In contrast, the surface topography of C. australasica and C. inodora seeds was more like that of the cultivated species, C. × aurantifolia and C. × limon. Seed morphology, especially surface topography, was found to be a useful tool for taxonomic identification in Australian wild citrus.     

Porcine IgE in the context of experimental food allergy: purification and isotype-specific antibodies

Measurement of allergen-specific immunoglobulin E (IgE) is a common practice in the investigation of allergy. It has not been possible to measure porcine IgE due to unavailability of anti-porcine IgE. This study was undertaken to purify and characterize porcine IgE from sera of allergic pigs, identify heterologous anti-IgE reactive with pig IgE and to use purified heavy (H) chain of porcine IgE to generate rabbit anti-IgE. A four-step process for the purification of porcine IgE is reported using ammonium sulphate precipitation, Protein G affinity chromatography, DEAE cellulose anion-exchange chromatography and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) to obtain IgE H chain. The resultant IgE was evaluated for purity using SDS-PAGE and immunoreactivity was detected by Prausnitz-Küstner (PK) tests and passive cutaneous anaphylaxis with the allergen, crude peanut extract, used to induce experimental allergy. Cross-reactivity with anti-mouse and anti-human IgE antibodies were confirmed in western blot and enzyme-linked immunosorbent assays (ELISA). The H chain of IgE was excised from SDS-PAGE gels and used to develop rabbit anti-porcine IgE antisera. Antiserum obtained from rabbits immunized with porcine IgE, as well as heterologous murine and human-specific anti-IgE, induced reverse cutaneous anaphylaxis in pig skin and detected allergen-specific IgE in ELISA but did not react with IgG H chain in western blots. These results confirm allergy-associated bioactivity of porcine IgE and describe both homologous and heterologous anti-pig IgE suitable for use in allergen-specific and other assays. This will enhance utility of pig allergy models and provide an additional measure of type-2 immune response in pigs.     

Surveying soil faunal communities using a direct molecular approach

Soil faunal communities are often phylogenetically diverse and the accurate assessment of the taxonomic structure of these communities is both time-consuming and requires a high level of taxonomic expertise. Here we describe a DNA sequence-based methodology for characterizing soil micro- and mesofaunal communities that is similar to the molecular approaches commonly used to survey soil microbial diversity. The technique involves the direct extraction of faunal DNA from soil, PCR amplification of the extracted DNA with metazoan-specific primers, followed by the construction of clone libraries and direct sequencing of individual PCR products. We used this technique to characterize micro- and mesofaunal community composition from six individual soils representing two land-use types. The technique captured the more abundant faunal groups in the soils (nematodes, Collembola, Acari, tardigrades, enchytraeids) and provided sufficient taxonomic resolution to describe the overall structure of the communities. We compared the results obtained using this molecular approach to results obtained using a traditional, microscopy-based approach and found that the results were broadly similar. However, since biases are inherent in both methods it remains unclear which method provides a more accurate assessment of soil faunal community composition. Although this molecular approach has some distinct disadvantages over the more widely-used direct extraction methods, one advantage is that the taxonomic identification it can provide will be more accurate and consistent across research groups, facilitating effective comparisons of mesofaunal surveys.     

Are the Australian poultry industries vulnerable to large outbreaks of highly pathogenic avian influenza?

Objective   To describe the structure of the Australian poultry industry and discuss the potential for highly pathogenic avian influenza (HPAI) to spread between Australian poultry farms.
Procedure   High densities of poultry farms, frequent contacts between farms by service providers, the supply of live poultry markets (LPM) and the presence of free-range duck flocks in affected regions have been identified as risk factors for the spread of HPAI between flocks in outbreaks causing the death or destruction of over 1 million poultry overseas. Data on 1,594 commercial Australian chicken meat, chicken egg, duck and turkey farms were collected by a telephone questionnaire of farm managers to assess the risk of a HPAI outbreak in Australia.
Results and Discussion   Five regions of Australia had farm densities comparable to overseas regions that experienced widespread HPAI. Common service providers routinely contacted different classes and types of farms over wide geographic areas. However, no responding farms supplied LPM and the majority of duck farms did not produce free-range ducks.
Conclusion   Outbreaks of HPAI have the potential to cause serious impacts on the Australian poultry industry. The risk posted by LPM and free-range ducks is limited, but the movement of genetic stock and common service providers could spread infection between companies, industries or geographical regions. Biosecurity measures are therefore considered critical to limit the secondary spread of infection should an outbreak occur.