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The design of nonfullerene acceptors (NFAs), which comprise donor and acceptor moieties, has led to significant improvement in organic photovoltaic (OPV) device performance over the past few years. Although there have been many NFAs synthesized and device-optimized, there have been fewer studies on the excited-state photophysics of donor-acceptor-containing NFAs. Using a combination of femtosecond transient absorption spectroscopy and time-resolved photoluminescence (PL), we have investigated the excited-state photophysical processes in three donor-acceptor-containing NFAs, where the chemical structure of the NFAs are systematically modified to allow direct comparison (D-A1-A1-D, D-A1-D, and D-A1-A2, where D represents 9,9-di-n-propylfluorene, A1 represents benzothiadiazole, and A2 represents dicyanovinyl). A large triplet population was observed for the dimer NFA (D-A1-A1-D), whereas for D-A1-D or D-A1-A2, the nonradiative decay rate was significantly decreased, and higher PL quantum yields observed. Furthermore, a singlet exciton relaxation process between S1∗ and S1 on the picosecond timescale was observed for each of the NFAs, although the mechanism was not always the same. Torsional relaxation was found to dominate the picosecond singlet relaxation for D-A1-D and D-A1-A2 in solution and film, and for D-A1-A1-D in solution. In the film, the singlet excited state of D-A1-A1-D predominantly relaxed via resonant excitonic energy transfer. The observation of singlet relaxation on the tens of picosecond timescale also provides a plausible explanation to the reduced VOC loss commonly associated with NFA-based OPV devices.

Couch smut, caused by Ustilago cynodontis, is an economically important disease of Cynodon dactylon, the most widely planted warm season turfgrass in Australia. The disease is distributed across all states and mainland territories of Australia, and is found worldwide wherever the host plant is present. The most characteristic disease symptoms are expressed at the flowering stage, when the inflorescence is partly or entirely destroyed and covered by a mass of black powdery spores. However, there are also less obvious impacts of the disease on plant growth such as a more erect growth habit, and a reduced rate of stolon extension and root development, leading to lower levels of tolerance of the turf to wear during usage, and greater amounts of wastage during harvest due to the roll breaking at points of infection. Ustilago cynodontis was first described nearly 130 years ago but pathogen biology and disease epidemiology are still poorly understood, hindering development of disease management strategies. We review the current knowledge and understanding of couch smut biology, the history of its occurrence, distribution and impact, and existing disease management practices to identify the gaps in knowledge that require further research.

Food wastage due to spoiling is a global economic issue and contributes to over-farming and overfishing with real environmental consequences. Smart food packaging is a promising solution to this problem, the concept of which is to incorporate responsive sensors that allow direct monitoring of the gasses released from the decay of food into a label that provides a visual indicator to the consumer as to whether the food is fresh or has spoiled. Here we report two dicyanovinyl-fluorene-benzothiadiazole-based fluorescent compounds, K12 and K12b, both of which showed rapid response to biogenic amines via two independent mechanisms. When primary alkyl amines were present in solution, they underwent an aza-Michael addition with the dicyanovinyl group of the sensing material, resulting in a rapid colour change. The reaction products of K12 and K12b with primary amines showed a decrease and increase in the fluorescence quantum yield, respectively, enabling a unique dual-sensor array with turn-off/turn-on response. In addition, fluorescence quenching via photoinduced hole transfer was observed in the solid-state sensor films with a wide range of primary, secondary and tertiary amines, enabling rapid and sensitive detection of amine vapours. Finally, we show as proof-of-concept that the fluorescence quenching response of sensing films was observable at cadaverine concentrations relevant to the food industry.

Bulk heterojunction organic solar cells continue to show steady photoconversion efficiency improvements. However, single component organic solar cells are a particularly attractive alternative due to the relative simplicity of device manufacture. It has been proposed that organic semiconductors with a high dielectric constant (≈10) could give rise to spontaneous free charge carrier generation upon photoexcitation. In this manuscript, factors are explored that affect the dielectric constant of organic semiconductors, particularly the optical-frequency dielectric constant. The properties of monomers, dimers and trimers of two isoelectronic families of materials that have acceptor units composed of one or two dicyanovinylbenzothiadiazole moieties and one to three donor units are compared. The donor components are composed of either fluorenyl or cyclopentadithiophene moieties with the same glycol-based solubilizing groups. It is found that chromophore planarity and orientation with respect to the substrate, and film density affect the optical and electronic properties of the materials, especially the high-frequency dielectric constant. The results also indicate that delocalization of the highest occupied and lowest unoccupied molecular orbitals is a critical factor. The dimer with two dicyanovinylbenzothiadiazole moieties and two dithienocyclopentadiene units is found to have the highest optical frequency dielectric constant and overall performance.

As Australian fruit and vegetable breeding programmes by public research institutions are progressively downsized or curtailed, new cultivars for production horticulture are increasingly being sourced from breeding programmes of overseas companies. Typically, such cultivars are purchased initially on the basis of their description and performance overseas, together with price. However, there is a significant risk that these could fail under Australian conditions and markets: for example, disease resistance claims may not hold up when exposed to different races of the causal organism in Australia; flavour and visual attributes may not suit Australian consumers; some cultivars may not prove as productive as found overseas; and unforeseen genetic weaknesses may become apparent. This paper reports results of irrigated field trials conducted in south-east Queensland over 2 years using melon (Cucumis melo) cultivars sourced from seed companies in Taiwan, Vietnam, China and USA. A preliminary screening trial in year 1 was used to shortlist a smaller number of cultivars for more detailed trials in year 2 to assess their potential productivity for commercial use and their novelty appeal for non-commercial markets.

Phytophagous mites were first identified as a problem in warm-season turfgrasses in Australia around 80 years ago. In production turfgrass fields, slower growth and weakening of sod strength by mites can cause serious commercial losses through breakage of harvested rolls. Elsewhere, mite infestation is associated with poor wear resistance coupled with very slow recovery of turf on playing fields, thereby reducing the usage that is possible on such fields. At the same time, knowledge about turfgrass mites is lacking: specifically, which mite group/species is/are causing damage and to which turfgrass species. There has long been an underlying assumption, based mainly on overseas literature, that mites of the family Eriophyidae are the main cause of the distorted growth symptoms frequently seen and attributed to mite damage. During the 2010/11 growing season, an Australia-wide survey was conducted, sampling seven warm-season turfgrass genera to determine the mites present in each case. This paper reports the results of that survey, together with data from more recent mite infestations sampled during the subsequent threeyear period. Based on their frequency of occurrence, tenuipalpid mites from the genus Dolichotetranychus appear to be at least as important as eriophyoid mites on Cynodon spp.; Dolichotetranychus mites were also recorded from two survey samples of Zoysia spp. but not in subsequent sampling. Eriophyoid mites of the genus Aceria were found on Cynodon spp., with possibly a second species on Zoysia species. A number of mixed tenuipalpid/eriophyoid populations have also been found on Cynodon species. A Steneotarsonemus species (Tarsonemidae) was found associated with Pennisetum clandestinum. Grass-webbing tetranychid mites (Oligonychus spp.) also occasionally affect a wide range of warm-season turf and other grasses non-selectively.

The modern Australian turfgrass industry developed from the period between World Wars I and II, in response to increasing urbanisation and construction of more sophisticated, higher quality sporting facilities. Its development intensified from the 1960s onwards with selection of the first widely used local varieties and import of new US-bred greens hybrids. This timetable, together with its underlying drivers, is similar to that in other developed countries in North America, Europe and southern Africa. However, supporting turfgrass education and research have developed very differently in Australia. Vocational greenkeeper training started in the 1940s with instructors from the NSW agriculture department, but moved into the Technical and Further Education (TAFE) system in the 1950s and has developed from there in all states. University-based training at post-graduate, and now undergraduate, level has become more available in the past 20-30 years, but is still a relatively small component within the overall tertiary education sector for agriculture and environmental science. In Australia, food-and fibre-based industries have been backed by strong, stable government research for over 100 years, in contrast to turfgrass (and lifestyle horticulture generally) where formal research support from state government departments has been limited, sporadic and lacked continuity. University research initiated in the past 20-30 years remains limited but is increasing in response to industry funding. Research into specific turfgrass problems has also been conducted over the past 50-80 years by private industry-funded providers, which have come and gone at regular intervals. Australia lacks a numerically strong nucleus of technically competent scientists and educators to provide independent advice to the turfgrass industry. The implications of this in terms of the quality of information accessed by practitioners are explored.

The flat mite Dolichotetranychus australianus (Womersley, 1943) – a significant pest of Cynodon turfgrasses in Australia and Africa – is redescribed on the basis of new Australian material collected from C. dactylon (bermudagrass, green couchgrass) and its hybrid C. dactylon × transvaalensis. All active life stages are described, leg chaetotaxy is provided, anomalous features are noted and the specimens compared with type material. The species is widespread in Queensland and is probably present anywhere that C. dactylon is grown in Australia, as indicated from its presence in other states. Photographs of its colonies and damage to turfgrass are presented, and damage symptoms are compared with similar damage caused by Aceria cynodoniensis (Trombidiformes: Eriophyidae). Dolichotetranychus summers Pritchard and Baker, 1952 known from C. dactylon in California, is redescribed from type material and confirmed as a species distinct from D. australianus, with both sexes of D. summersi lacking genital set...

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (~30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6–2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8–3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (⩽3.8) hybrid scenario has been extended to the high-density levels necessary for radiating divertor operation, achieving ~40% divertor heat flux reduction using either argon or neon with P tot up to 15 MW.

The lifestyle horticulture industry can best be described as a “living green industry”. It involves the production, sale, management and maintenance of plants used for environmental, recreational and leisure purposes. In Australia, this specialised sector of horticulture has become one of the more profitable and rapidly growing primary industries since World War II. This paper discusses the significance of the Australian lifestyle horticulture industry in terms of its environmental, aesthetic, social and recreational values in the urban environment where 87% of Australians live, work and play, as well as the impact of these commodities and services on the health and well-being of those communities. The industry also generates substantial direct and indirect economic benefits. However, the few available statistics from which the size of the industry can be assessed are, at best, unreliable. While these do indicate that the lifestyle horticulture industry is one of the largest agricultural industry groupings, they grossly underestimate the full value of lifestyle horticulture activities in Australia. As a result, the commodities and services associated with the lifestyle horticulture industry have been poorly recognised and undervalued by the wider agricultural sector. Governments at all levels, as well as the community at large, can be said to take the value and benefits from the lifestyle horticulture industry for granted. Greater discussion needs to take place between the government, industry and community to increase teaching, research and extension funding into the lifestyle horticulture industry that contributes so much to AustraliaRSQUOs livelihood, lifestyle and quality of life.

Wear damage is one of the biggest problems associated with continuous use on sports and recreational turfgrass fields. Wear tolerance of 8 bermudagrass (Cynodon spp.) genotypes including 6 ecotypes collected from regional Australia and two commercial cultivars were evaluated in the field. Green cover after wear treatment of ecotypes 394 and MED3 was over 50% higher than the lowest genotypes. The wear tolerant genotypes also had significantly higher acid detergent fibre content, cellulose, lignin and total cell wall content than wear susceptible genotypes. Optical and scanning electron microscopies were used to study stolon and leaf transverse sections and leaf surface characteristics, respectively. Transverse sections of stolons and leaves, suggested that the fibre area surrounding vascular bundles of the wear tolerant genotypes was about 50% higher than the wear susceptible ones. Scanning electron micrographs of the leaf surface suggested that the arrangement of epidermal cells formed a ridged pattern. The gaps between the ridges of wear tolerant genotypes were shorter than those of the wear susceptible genotypes. Collectively, these results suggested that the mechanism of wear tolerance was associated with high fibre content in stolons and leaves. In addition, we suggest that the wear tolerant genotypes have a denser ridge pattern of epidermal cells probably giving the leaves greater tensile strength.

Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species) against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production. Accessions sown at a site were determined by prior experience with them on a range of soils. High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp. Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana. The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species. While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises. Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities.Keywords: Herbicide tolerance, persistence, forage yield, establishment ease, commercialization, seed production.DOI: 10.17138/TGFT(3)15-26

This chapter focuses on the practical implications of physiological processes on seed crop location and management, and on seed germination and establishment. The tiller is the basic growth unit in grasses. Floral initiation signals the start of the reproductive phase. Flowering occurs when the flowers on the inflorescence finally emerge in clear view and pollen is dispersed during anthesis. The timing of flowering largely determines the date of harvest, as well as stresses that could affect the plant. Seed dormancy is the failure of an intact viable caryopsis, contained within any covering structures it may have, to complete germination when placed under favorable moisture, oxygen, and temperature conditions. Embryo growth is intrinsically associated with imbibition and dormancy. Knowledge of plant development and flowering behavior is reflected in the management of seed crops to maximize potential yields, and also can highlight important limiting factors in certain environments on the production of good quality seed.

Bermudagrasses (Cynodon spp.) are genetically and morphologically diverse warm-season species that are valuable for turf and forage. Diverse accessions of Cynodon are preserved in various germplasm banks in Asia, Europe, and the United States. However, the extent of genetic and ecological diversity within Australia has not been previously explored and characterized. To address this issue, a broad-scale collection of Cynodon germplasm across Australia was recently conducted. A core collection was generated from this resource to optimize its utilization in breeding and research. Genetic diversity of 690 Cynodon accessions was characterized using 16 expressed sequence tag (EST)-simple sequence repeat (SSR) markers. The mean number of alleles generated was 7.44 per marker. Genetic data was combined with passport, ploidy level, morphological, and experimental performance data to generate a core collection using a directed stratified sampling method. The core collection comprised 13% of the source germplasm and captured 96% of the allelic diversity. Redundancy within the core collection was avoided with all accessions representing unique genotypes. This core collection will facilitate the future use of Australian germplasm in Cynodon breeding, genomics, conservation, taxonomy, and phylogeographical research.

Identification of the five noxious weedy Sporobolus species from non-weedy and native species in Australia is extremely difficult. Furthermore, seeds of these species, which are found in commercial seed lots, are morphologically indistinguishable. The lack of a reliable identification protocol is contributing to the rapid spread of these noxious weedy species within Australia. A polymerase chain reaction-restriction fragment length polymorphism approach carried out on nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) sequences was used to create a molecular diagnostic tool. To develop this tool, 40 ITS sequences generated from 14 Sporobolus species were used. A restriction enzyme (MvnI) was identified which could cut the ITS sequences from the noxious weedy species into two approximately equal fragments, while not cutting those from all other species. When tested on 23 randomly selected seed samples, identification was accomplished with 100% accuracy, suggesting a possible application in seed certification programmes. © 2010 The Authors. Weed Research

Water use in both urban and rural communities has become an enormous environmental and social issue, and over 30% of domestic water consumption is applied outdoors. To use Australia's unique biodiversity to select turfgrasses that maintain quality with reduced inputs of water and nutrients, we have collected about 500 indigenous couch grass genotypes and have begun to characterise them using physiological and genomics tools. Here we report on experiments that aim to develop the methodologies for screening a large number of genotypes for water use efficiency. Eight Cynodon grasses were grown in 40-cm-long PVC tubes with two soil types, two cutting heights, and four replications. The plants were grown at field capacity for several weeks prior to applying a terminal water stress. A survival period was estimated based on the time from the last watering to the time that all green leaf was lost. Large genotypic differences in survival period of up to 14 days were observed. Two genotypes, '81-1' and 'CT2', outperformed the other genotypes for survival period, possibly due to lower rates of evapotranspiration either through lower stomatal conductance and/or lower leaf area.

Traction is recognised as an important component of the overall playability and safety of a sportsfield. It relates to the "grip", or footing, provided through an athlete's shoe when in contact with the surface, and is normally measured by the torque generated when a weighted studded disc apparatus is dropped onto the turf and twisted manually. This paper describes the development of an automated traction tester, which mechanises the dropping and twisting of the weighted studded disc. By standardising these operational stages, more repeatable and reliable results can be expected than from the original hand-operated design where positioning of the disc and speed of rotation are controlled manually and so can vary from one measurement to the next. As well as measuring the maximum torque reached during rotation of the studded disc, the automated traction tester generates a profile of torque showing changes over time and calculates the angle through which the studded disc moved before reaching maximum torque. These aspects are now covered by a utility patent (PAT/AU/2004270767). Use of the automated traction tester is illustrated by comparative data for a range of warm-season turfgrasses, by comparisons of traction under different surface conditions generated by wear on Cynodon dactylon cultivars, and by the effects of environment, management and playing patterns on traction across a multi-use sports stadium.

A seed supply system can be defined in general terms as that combination of components, processes and their organisation, along with the interactions and support involved in the production and marketing of seeds of one or more species to a particular user–client grouping in an ongoing way. Seed supply systems come in a variety of forms, and operate at a range of levels (national, regional and local) and with different plant materials used for different purposes. In all cases, however, the public and the private sectors have complementary roles in ensuring that there is an effective seed supply system, which can meet consumer needs in terms of the range of plant materials available and the quantities and quality of seed required at an affordable price. Nationally, it is the government that sets the policy framework within which seed supply systems must operate, and also provides some supporting infrastructure. The private sector then is responsible for the timely and cost-effective production and delivery of seed to end users/clients within the policy framework that has been set by government. The balance in terms of public–private sector roles and responsibilities differs from place to place and changes over time. This paper discusses the factors that help shape what is an effective seed supply system under a particular set of circumstances, but one that may not necessarily be as effective in other countries/regions or with a different product mix. It also considers the forces that lead to a gradual evolution of the system over time and to recent and more radical changes in major developed countries. The latter shift has been brought about by the commercial opportunities presented by genetic engineering and legal protection of the intellectual property (IP) in new plant varieties, coupled with a shift in government policy towards deregulation of the economy (and so greater industry self-regulation in areas like quality assurance). These factors have led to far-reaching structural changes in relation to commercial seed production and delivery in the developed world over the past decade. The recent changes in seed supply arrangements were focused initially on high volume arable food crops in the larger developed economies of North America and western Europe. However, they are now gradually moving through to lower volume seed markets and to smaller, less developed economies where they will have different implications for the development of effective country-specific seed supply policies.

In future burning plasma experiments, a promising method for the diagnosis of first wall erosion is to detect the onset of emission from nonintrinsic materials embedded in the plasma facing components as they are revealed and enter the confined plasma. Likely high Z species were introduced into the Joint European Torus plasmas by laser ablation. Results from targets of single species (W and Hf) and dual species (W/Hf composite) are presented. The composite target experiment has shown that it is possible to distinguish reliably between emission from near neighbor heavy elements, even with instrument resolutions of Δλ/λ∼0.001. Forward prediction to power plant conditions necessitates a model of the complex spectra and a system for generating the required atomic data and producing spectral feature emissivity coefficients is described. An important consideration is to enable exploration of different instrumentation so the spectral resolution of the compound features are tuned to the diagnostic capability.

Available evidence suggests that there are at least two locations for dormancy mechanisms in primary dormant seeds: mechanisms based within the embryo covering structures, and mechanisms based within the embryo. Mechanisms within the covering structures may involve mechanical, permeability and chemical barriers to germination. Mechanisms within the embryo may involve the expression of certain genes, levels of certain plant growth regulators, the activity of important respiratory pathways or the mobilisation and utilisation of food reserves. In addition, some embryos may be too immature to germinate immediately and must undergo a further growth phase before germination is possible. An individual species could have one or several of these various dormancy mechanisms and these mechanisms need to be understood when selecting treatments to overcome dormancy. The way in which certain dormancy breaking agents are thought to work is discussed and practical applications of such agents in field situations are explained.

A number of useful Australian native grasses have been identified for various situations: for turf, amenity, and ornamental purposes; for revegetation of mine spoil, roadsides, and degraded land; and as forages. Their commercialisation depends on developing appropriate seed‐harvesting and processing technology, thereby ensuring that seed is produced in a form that can be sown satisfactorily and gives reliable establishment. While conventional header harvesters can be used with some species (e.g.,Astrebla lappacea), beater and (especially) brush harvesters have been more successful with many others, particularly grasses with light, difficult‐to‐handle, chaffy seeds. After harvest, chaffy seeds can be processed to make their subsequent handling and sowing easier. Choice of processing method depends on the structural complexity of the dispersal units and on the particular chaffy appendages involved. Awns and sterile spikelets are comparatively easy to remove, with surface hairs and bristles the most...

La presente etude decrit l'evolution des peches du crabe des neiges (Chionoecetes opilio) et ses effets sur la gestion de stocks de l'espece dans le sud du Golfe du Saint-Laurent. Cette peche, actuellement lucrative (sa valeur estimative au debarquement etait de plus de 125 millions de dollars canadiens en 1994), a connu les hauts et les bas qui caracterisent la plupart des pecheries et les effets qui s'ensuivent, notamment les consequences socio-economiques et les relations parfois tendues entre l'industrie et l'organisme de gestion des peches, en l'occurrence le Ministere des Peches et des Oceans (MPO). On constate cependant aujourd'hui qu'une cooperation d'un niveau remarquable s'est etablie entre l'industrie et le MPO depuis la derniere periode de diminution spectaculaire du stock (1987-1989). Depuis lors, le stock se reconstitue et il est aussi mieux gere. Il y a a cela quatre raisons: (1) on a note en 1988-1989 une intensification du recrutement de crabes de petite taille; (2) les progres notables realises dans la comprehension de la biologie complexe du crabe des neiges et l'elaboration d'une methode precise et fiable d'evaluation du stock ont ensemble permis de rassembler des donnees systematiques, fiables et credibles pour la prevision de la quantite et de la distribution geographique de la biomasse exploitable avant la saison de peche; (3) les responsables de l'industrie, de concert avec leurs associations, ont deploye de grands efforts pour convaincre les pecheurs que leur stock etait en danger et qu'une collaboration etroite avec le MPO etait la voie de l'avenir; (4) l'industrie et le MPO (ses biologistes et ses agents de gestion des peches) ont elabore en collaboration une approche de gestion fondee sur les avis scientifiques pour sortir du marasme. Cette etude expose de plus le probleme difficile qui se pose actuellement aux responsables de la gestion des peches par suite d'une part du moratoire de la peche du poisson de fond sur toute l'etendue du Golfe du Saint-Laurent et des pressions exercees en consequence par les pecheurs du poisson de fond desoccupes pour obtenir les lucratifs droits de peche au crabe des neiges, et d'autre part des previsions optimistes a court terme mais pessimistes a long terme touchant l'abondance du crabe des neiges, probleme qui pourrait se formuler ainsi: devons-nous redistribuer la richesse, et si la reponse est oui, a qui, comment et pour combien de temps?

A new species of tarsonemid mite, Steneotarsonemus hippodromus sp. nov., is described from kikuyu grass Pennisetum clandestinum (Poaceae). The new species is the fifth species of the subgenus Steneotarsonemoides. Keys to the subgenera of Steneotarsonemus and species of Steneotarsonemoides are provided, as is a list of species in each subgenus of Steneotarsonemus.

Cynodon L. C. Rich comprises warm season grass species that are valuable as turf and forage in warm climates across the globe. Traditionally, Cynodon breeding programs have aimed to produce varieties with improved turf and forage grass quality characteristics. More recent goals, such as improved abiotic stress tolerance, aim to address challenges associated with climate change. Germplasm collections representing a fraction of the global distribution of Cynodon comprise the plant resource for these breeding programs. We compared a core collection consisting of 116 Australian genotypes with an international core collection of 59 genotypes representing Cynodon’s global distribution. Our aims were to determine whether unique genetic diversity exists amongst Australian Cynodon that may enhance international breeding resources. This research will facilitate the incorporation of Australian Cynodon genetic resources, which have expanded and naturalized under harsh Australian climates, into existing germplasm collections.

This book is the latest from Drs Carrow and Duncan, who have published and lectured extensively on soil salinity and sodicity issues and the management of such soils over the past 15 years or so. How knowledge in this area, particularly in terms of practical management, has developed over this period can be seen in the size of this latest book, with more than twice the number of pages of the first book by Carrow and Duncan (1998)...

Bidirectional errorfree 140 Mbit/s OQPSK-signal transmission with optically generated microwaves in the 18-19 GHz-band is reported. Two microwave carriers one for the radio link to the mobile receiver (down link) and one for the uplink-microwave mixer in the base station are generated by a simple optical upconversion technique.

In Australia, little work has been carried out on the im-provement of tropical or subtropical pastures in recent years. There seems to be an increasing demand for pas-tures that can withstand heavy grazing, while producing high yields of high quality forage in the humid subtropi-cal regions of Australia. Most graziers, who live in these areas, have small acreages, which they graze intensively. Cynodon spp. represent a potential source of grasses with these attributes. This study will evaluate the pasture potential of a large number of bermudagrass (Cynodon spp.) ecotypes collected from across Australia.

The substituted benzamides or orthopramides are used to treat gastrointestinal and psychotic disorders. The orthopramide clebopride, a potent dopaminergic antagonist, blocks emesis in dogs and stereotyped behavior in rodents. Since the release of prolactin is inhibited by dopamine, antidopaminergic drugs may be useful to increase lactation in nursing mothers. The present work examines the morphological and histological alterations produced by long-term treatment of puerperal and virgin female rats with clebopride. Clebopride induced significant hyperplasia of parenchymal secretory units and stimulated milk secretion in both groups of rats. However, only in virgin rats was mammary weight significantly increased.

Loch et al. (1995) examined the recovery of the southwestern Gulf of St. Lawrence snow crab fishery after its nearly collapsed situation in 1988–1989 by highlighting industry involvement, better management practices, and a new survey method. This review did not elucidate underlying biological events but rather emphasized the relationship established among science, management, and industry, which resulted in a unique partnership between the Department of Fisheries and Oceans and industry. Nevertheless, some readers have the impression that the recovery of the snow crab stock was because of the good fishery management and not underlying biological events (Sainte-Marie 1997). In addition, there are some unclear statements that may mislead the reader about the general consensus of Canadian snow crab biologists on snow crab stock dynamics and management approach. Therefore, this response deals with further clarification of Loch et al. (1995) by including the most up to date accounts of developments in snow crab biology and stock assessment in eastern Canada.

Based on morphological features alone, there is considerable difficulty in identifying the 5 most economically damaging weed species of Sporobolus [viz. S. pyramidalis P. Beauv., S. natalensis (Steud.) Dur and Schinz, S. fertilis (Steud.) Clayton, S. africanus (Poir.) Robyns and Tourney, and S. jacquemontii Kunth.] found in Australia. A polymerase chain reaction (PCR)-based random amplified of polymorphic DNA (RAPD) technique was used to create a series of genetic markers that could positively identify the 5 major weeds from the other less damaging weedy and native Sporobolus species. In the initial RAPD profiling experiment, using arbitrarily selected primers and involving 12 species of Sporobolus, 12 genetic markers were found that, when used in combination, could consistently identify the 5 weedy species from all others. Of these 12 markers, the most diagnostic were UBC51490 for S. pyramidalis and S. natalensis; UBC43310, 2000, 2100 for S. fertilis and S. africanus; and OPA20850 and UBC43470 for S. jacquemontii. Species-specific markers could be found only for S. jacquemontii. In an effort to understand why there was difficulty in obtaining species-specific markers for some of the weedy species, a RAPD data matrix was created using 40 RAPD products. These 40 products amplified by 6 random primers from 45 individuals belonging to 12 species, were then subjected to numerical taxonomy and multivariate system (NTSYS pc version 1.70) analysis. The RAPD similarity matrix generated from the analysis indicated that S. pyramidalis was genetically more similar to S. natalensis than to other species of the ‘S. indicus complex’. Similarly, S. jacquemontii was more similar to S. pyramidalis, and S. fertilis was more similar to S. africanus than to other species of the complex. Sporobolus pyramidalis, S. jacquemontii, S. africanus, and S. creber exhibited a low within-species genetic diversity, whereas high genetic diversity was observed within S. natalensis, S. fertilis, S. sessilis, S. elongates, and S. laxus. Cluster analysis placed all of the introduced species (major and minor weedy species) into one major cluster, with S. pyramidalis and S. natalensis in one distinct subcluster and S. fertilis and S. africanus in another. The native species formed separate clusters in the phenograms. The close genetic similarity of S. pyramidalis to S. natalensis, and S. fertilis to S. africanus may explain the difficulty in obtaining RAPD species-specific markers. The importance of these results will be within the Australian dairy and beef industries and will aid in the development of integrated management strategy for these weeds.