Effect of substrate,medium composition,irradiance and ventilation on jojoba plantlets at the rooting stage of micropropagation

The effect of substrate, medium composition, irradiance and ventilation on rooting percentage, and root morphology and functioning with respect to mineral uptake was investigated in jojoba [Simmondsia chinensis (Link) Schneider]. Plantlets grown on Sorbarod plugs embedded in perlite accumulated more biomass and showed better rooting than plantlets grown on Sorbarod plugs embedded in agar. In plants grown on the latter substrate, the addition of sucrose to water or salts media promoted rooting and accumulation of shoot and root biomass. On perlite, rooting was high in all treatments, while root growth was enhanced only by 2% sucrose. Sucrose and irradiance had a positive synergistic effect on plantlet growth. Doubling the irradiance from 58 to 116 μE m⁻² s⁻¹ and using high ventilation (22-mm membrane) failed to improve rooting but promoted the ability of the stomata to close, thereby reducing water loss under ambient conditions. High irradiance and ventilation lowered the chlorophyll content, but without impairing biomass accumulation. Plantlets grown under enhanced ventilation and 0.5% sucrose formed fine roots within the cellulose plug and thick roots on the vessel floor. With the 2% sucrose supplementation, the roots were generally thicker, with very few thin roots being formed. ³⁶Cl uptake into plantlets and transport to the leaves decreased in plants exposed to a high sucrose concentration. Acclimatization of jojoba plantlets was improved by enhancing ventilation.     

Effects of benlate on leatherleaf fern growth,root morphology and rhizosphere bacteria

Reduced frond production as well as foliar disorders and root damage to leatherleaf fern (Rumohra adiantiformis [Forst.] Ching) coincided with the widespread use of Benlate fungicide in grower operations. These symptoms could not be explained by environmental conditions or the presence of new pathogens. The objective of this study was to examine the effects of Benlate at labeled rates on frond production, root morphology, and soil microbial characteristics of leatherleaf ferns. A separate experiment was conducted by adding Benlate at labeled drench rate to previously untreated soil to evaluate the promotion of soil bacteria. Benlate was applied to leatherleaf fern plants in the greenhouse at labeled foliar and drench rates for 17 months. Fronds were harvested during the last nine months. Roots of the ferns were examined using electron microscopy at termination of the experiment to determine physical and microbial characteristics of the roots. Rhizosphere bacteria were evaluated to determine counts and types. Lettuce seedling bioassays were conducted to evaluate bacterial isolates for possible deleterious effects on plants. Over the nine‐month harvest period, 181 fronds were harvested per pot from the control treatments, 162 for the Benlate foliar treatment, and 113 for the drench treatment. The Benlate drench rate resulted in significant reduction of frond production. However, the Benlate foliar rate was not significantly different from the control. Benlate application resulted in a reduction of root hairs and disruption of the root surfaces, especially at the drench rate. Total bacterial counts were not significantly different among Benlate treatments; however, the biodiversity of these populations was reduced with 46, 36, and 22 individual isolates identified for control, foliar, and drench rate treatments, respectively. Using a lettuce bioassay, compared to seedlings grown on sterile medium, the average seedling growth in the presence of isolates from the control treatment was 83%, 73% from the foliar rate treatment, and 60% from the drench rate treatment. The predominant deleterious isolates include Pseudomonas fluorescens, Ps. putida, and Ps. cepacia. In a laboratory experiment, these bacteria were shown to be promoted within the soil by Benlate application. These results indicate that Benlate has the potential to reduce yields of leatherleaf ferns. This reduction may be caused by direct action of the chemicals within the Benlate formulations or by the promotion of deleterious bacteria within the growing media.     

The use of Twitter for knowledge exchange on sustainable soil management

Encouraging the uptake of sustainable soil management practices often requires on‐farm experiential learning and adaptation over a sustained period, rather than the traditional knowledge transfer processes of identifying a problem and implementing a solution. Farmer‐to‐farmer learning networks are emerging with farmers experimenting and sharing knowledge about these practices amongst themselves. One potential communication channel for such interaction and knowledge sharing is social media and Twitter in particular. A content analysis of a Twitter account for an EU research project, SoilCare, and in‐depth qualitative interviews with five farmers using Twitter, was used to illustrate the extent and type of farmer‐to‐farmer knowledge sharing in relation to sustainable soil management practices. Evidence of farmer learning and knowledge sharing on Twitter with respect to these practices was identified. Twitter can capture the immediacy of the field operations and visual impacts in the field. Furthermore, the brief messages channelled through Twitter appeal to time‐constrained farmers. The ability for interaction around particular hashtags in Twitter is developing virtual networks of practice in relation to sustainable soil management. Within these networks, farmer champions are emerging that are respected by other farmers. Twitter works best for those actively seeking information, rather than passive recipients of new knowledge. Therefore, its use with other forms of face‐to‐face interaction as part of a blended learning approach is recommended. Twitter also offers a potential space for other actors, such as researchers and advisers, to interact and share knowledge with farmers.     

Expression and characterisation of the ovine respiratory syncytial virus (ORSV) G protein for use as a diagnostic reagent.

Respiratory syncytial virus (RSV) causes severe lower respiratory tract infection in children and calves. Antibodies to ovine RSV (ORSV) are common in sheep, but the clinical disease is not well defined. There is no report of ORSV infection in Australian sheep although respiratory distress syndrome has been described. This discrepancy may be due to the lack of a suitable diagnostic test. In this report, we have characterised the ORSV G protein in an attempt to study its relatedness to human and bovine RSV (HRSV, BRSV) and for use in the development of a suitable diagnostic assay. Full length and a truncated variant of ORSV G protein were expressed in mammalian cells and the expressed proteins characterised by indirect immunofluorescence and radioimmunoprecipitation assays. Our results indicate that like HRSV, the ORSV G protein is heavily glycosylated. The expressed protein was membrane bound as well as secreted and could be purified from culture supernatants and may be suitable for use in development of a diagnostic assay.     

Satellite tracking of wild dogs in south-eastern mainland Australian forests: Implications for management of a problematic top-order carnivore

Satellite tracking was used to follow the movements of a problematic top-order carnivore, the wild dog (Canis lupus dingo, C. lupus familiaris and their hybrids), in contiguous forested landscapes in south-eastern mainland Australia. Home range sizes of wild dogs were much larger than previously determined using conventional telemetry methods, averaging 10,000 ha with a maximum size of 59,000 ha over approximate 3-month periods. Wild dogs at sites with high abundance of kangaroos, wallabies and rabbits had smaller areas of occupancy than did dogs at sites with low availability of these preys. Despite mostly large home ranges, tracked animals were loyal to publicly-owned tenure and there were few instances where individuals moved large distances on to adjacent private tenure. Instead, movement behaviours of most tracked animals were characterised by repeated short distance forays, often at acute angles from previous locations. Consequently, home ranges were stable and otherwise well defined. Analysis of DNA from our study animals indicated that most individuals were of ‘dingo’ ancestry, but otherwise considered hybrids because of the presence of domestic dog genes. Only two of 24 animals could be considered as ‘pure’ dingo. Contemporary wild dog management demarcates lands where control is or is not undertaken, with the latter notionally acting to ‘conserve’ dingoes. Due to the large scale of movement of animals, existing control efforts likely impact over a greater area than previously suspected. Furthermore, our genetic findings suggest that conservation of dingoes in south-eastern mainland Australia is difficult to achieve. A modified approach to wild dog management is needed, taking account of the extent of range of individual animals and the existing genetic characteristics of populations.     

Application of electron spin resonance spectroscopy and spin probes to investigate the effect of ingredients on changes in wheat dough during heating

The change in microviscosity of the aqueous and lipid phases of wheat flour dough, during heating and subsequent cooling, has been measured using novel spin probes based on the isoindolin-yloxyl structure. The spin probes, water and/or lipid soluble, were used with combinations of dough ingredients: diacetyl tartaric acid ester of monoglycerides (DATEM), salt, yeast, and sodium ascorbate. The lipid soluble probe showed that DATEM does not produce a homogeneous phase with endogenous lipids but is found in a separate, less mobile phase. Also, the lipids were shown not to be involved in the baking process, although DATEM may be incorporated into the gelled starch matrix. The water soluble probe enabled starch gelatinization to be investigated in detail and showed that gelatinization produces a reduction of dielectric constant. The technique is appropriate for the detailed examination of the behavior of different ingredients during baking and also potentially to examine interactions between ingredients and flour components in dough.     

Serial exploitation of global sea cucumber fisheries

In recent decades, invertebrate fisheries have expanded in catch and value worldwide. One increasingly harvested group is sea cucumbers (class Holothuroidea), which are highly valued in Asia and sold as trepang or bêche‐de‐mer. We compiled global landings, economic data, and country‐specific assessment and management reports to synthesize global trends in sea cucumber fisheries, evaluate potential drivers, and test for local and global serial exploitation patterns. Although some sea cucumber fisheries have existed for centuries, catch trends of most individual fisheries followed boom‐and‐bust patterns since the 1950s, declining nearly as quickly as they expanded. New fisheries expanded five to six times faster in 1990 compared to 1960 and at an increasing distance from Asia, encompassing a global fishery by the 1990s. Global sea cucumber production was correlated to the Japanese yen at a leading lag. Regional assessments revealed that population declines from overfishing occurred in 81% of sea cucumber fisheries, average harvested body size declined in 35%, harvesters moved from near‐ to off‐shore regions in 51% and from high‐ to low‐value species in 76%. Thirty‐eight per cent of sea cucumber fisheries remained unregulated, and illegal catches were of concern in half. Our results suggest that development patterns of sea cucumber fisheries are largely predictable, often unsustainable and frequently too rapid for effective management responses. We discuss potential ecosystem and human community consequences and urge for better monitoring and reporting of catch and abundance, proper scientific stock assessment and consideration of international trade regulations to ensure long‐term and sustainable harvesting of sea cucumbers worldwide.     

Tropospheric ozone pollution reduces the yield of African crops

Northern, Southern and Equatorial Africa have been identified as among the regions most at risk from very high ozone concentrations. Whereas we know that many crop cultivars from Europe, north America and Asia are sensitive to ozone, almost nothing is known about the sensitivity of staple food crops in Africa to the pollutant. In this study cultivars of the African staple food crops, Triticum aestivum (wheat), Eleusine coracana (finger millet), Pennisetum glaucum (pearl millet) and Phaseolus vulgaris (bean) were exposed to an episodic ozone regime in solardomes in order to assess whether African crops are sensitive to ozone pollution. Extensive visible leaf injury due to ozone was shown for many cultivars, indicating high sensitivity to ozone. Reductions in total yield and 1,000-grain weight were found for T. aestivum and P. vulgaris, whereas there was no effect on yield for E. coracana and P. glaucum. There were differences in sensitivity to ozone for different cultivars of an individual crop, indicating that there could be possibilities for either cultivar selection or selective crop breeding to reduce sensitivity of these crops to ozone.     

Percutaneous absorption of methimazole: an in vitro study of the absorption pharmacokinetics for two different vehicles

The use of transdermal medications in cats has become popular in veterinary medicine due to the ease of administration compared to oral medication. However, the research to support systemic absorption of drugs applied to the pinna after transdermal administration in cats is limited. The aim of this study was to characterize the percutaneous absorption pharmacokinetics of methimazole in a lipophilic vehicle compared to methimazole in Pluronic^® lecithin organogel (PLO) using a finite dose applied to feline ear skin in an in vitro Franz cell model. The two formulations of methimazole (10 mg) were applied to the inner stratum corneum of six pairs of feline ears. The receptor medium was sampled up to 30 h post–administration, and methimazole concentrations were measured using high‐performance liquid chromatography (HPLC). Histological examination of all ears was undertaken as small differences in the thickness of ear skin may have contributed to inter‐individual differences in methimazole absorption between six cats. Methimazole was absorbed more completely across the pinnal skin when administered in the lipophilic vehicle compared to administration in the PLO gel (P < 0.001).