bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Cropping Systems at the Boundaries of the Pastoral and Cropping Zones in Southern Australia.
Authors: French RJ
Published: December 2005

A history of cropping at the margins between arable and pastoral lands is examined. Assessment is made of the climatic factors that caused the abandonment of cropping. These criteria are then used to assess the likelihood that future cropping will persist along the present pastoral margins in different states of Australia. A minimum requirement is that the ratio of water use to evaporation in the growing season should exceed 0.3. An analysis of past climatic data should also be made to identify sequences of years when rainfall was both above and below average. Periods of above-average rainfall can lead to undue optimism for future cropping. Simple climatic models are required so that farmers can use them to predict the rainfall in the growing season and thereby make appropriate management decisions. Farming is a complex technical and financial business and farmers will need skills in monitoring, measuring and recording factors that influence their livelihood.
Run-Off and Sediment Yield From a Semi-Arid Woodland in Eastern Australia. Ii. Variation in Some Soil Hydrological Properties Along a Gradient in Soil Surface Condition.
Authors: Eldridge DJ , Koen TB
Published: December 2005

Three sites on red earth soils were examined at Yathong Nature Reserve and 'Coan Downs' in central- western New South Wales. The sites represented a gradient in soil surface condition from a stable, uneroded and productive site, supporting moderately dense perennial grasses (site 1) to a moderately unstable and degraded site with few perennials and evidence of erosion (site 3). The hydrological characteristics of the three sites were measured using a rainfall simulator on plots with varying vegetation cover. Water ponded earlier at the degraded site, and run-off and sediment removal increased as the soil surface became more degraded. Associated with this was an increase in the importance of vegetation cover, and a decrease in the importance of soil physico-chemical variables as descriptors of soil hydrological properties. The results are consistent with the notion that vegetation plays a more important role in maintaining soil hydrological processes as the soil surface becomes more degraded.
Abundance, Distribution, and Rate of Increase of Feral Goats in Western Australia.
Authors: Southwell CJ , Pickles GS
Published: December 2005

Aerial survey of 1.2 million km2 of Western Australia in 1987 and 1990 indicated minimum feral goat populations (� standard error) of 363,000�44,000 and 596,500�41,200 respectively. The observed rate of increase over the three-year period was r = 0.17, corresponding to a finite rate of increase of 18% per annum. In the period between the surveys an average of 187,000 goats were known to be commercially harvested each year. The observed rate of increase is below maximum potential rates of increase predicted theoretically for goat-sized mammals and derived from age-specific fecundity and mortality data for feral goats in South Australia.
The Climatology and Meteorology of High Fire Danger in the Northern Territory.
Authors: Tapper NJ , Garden G , Gill J , Fernon J
Published: December 2005

In most areas of Australia the calculation of a fire danger index (FDI) is the cornerstone of fie weather forecasting and provides an operationally objective basis for the issue of fire weather warnings. FDI's are derived from the observation or prediction of a number of basic meteorological parameters which are then combined with information on fuel characteristics. The forest and grassland fire danger in southern Australia is greatest during the austral summer and is characterised by long periods of low fire danger interspersed with occasional extreme fire danger events. By contrast, much of tropical and subtropical Australia shows a distinctly different seasonality, magnitude and frequency of fire danger. The problem is essentially one of the austral winter-spring (dry season) period and is characterised by extended periods of moderate to high fire danger. This paper provides a broad climatological background to the problem of high fire danger in northern Australia, concentrating in particular on the Northern Territory. The paper also addresses particular meteorological situations in northern Australia which give rise to elevated fire danger. Two synoptic-scale weather patterns are discussed in particular; the passage of prefrontal troughs which seasonally produce high fire danger in the region of the tropic, and winter subtropical ridging which produces strong winds and high fire danger over the north of the continent during the dry season.
An Alternative Understanding of the Relationship Between the Ecosystem and the Social System - Implications for Land Management in Semi-Arid Australia.
Authors: Fitzhardinge G
Published: December 2005

The growing concerns of the wider community for bio-diversity, ecological maintenance and sustainable long term productivity of Australia's rangelands has focussed attention on land management practices in the semi-arid and arid areas. Where conventional farming paradigms concentrated on farming practices and methods, the paradigms of sustainability rest heavily on changes to farming philosophy for their success. The basic challenges have been well understood for years, and almost all the research has gone into the process of understanding the resource. There is little understanding of the relationship between the ecosystem and either society in general, or the local community. The basic relationship, that between society and the ecosystem, is being overlooked. The social system determines human objectives and the ecosystem presents a range of possibilities through which these objectives are to be realised. Using the work of Ingold, it is argued that technology, ideology and structure are the products of the relationship between society and the ecosystem. The interaction between the ecosystem and the social system then presents a set of possible outcomes that culture atteinpts to solve. There is a need to shift attention from technology and ideology to examining and understanding the relationship between the social system and the ecosystem if the desired changes, such as the maintenance of biodiversity or sustainability, are to be more than superficial.
Establishment and Survival of Pasture Grasses Surface-Sown Into Wheat Stubble in North-Western New South Wales.
Authors: Campbell MH , Bowman AM , Bellotti WD , Friend JJ , Nicol HI
Published: December 2005

In four experiments near Walgett, New South Wales, between 1987 and 1990, the establishment and survival of Astrebla lappacea, Setaria incrassata, Panicurn coloraturn var. rnakarikariense and Cenchrus ciliaris were determined when surface-sown into low, reduced or heavy stubble just before or after harvesting wheat (November or December). Despite external deleterious factors affecting three experiments, grasses established in the first six months after sowing in all experiments unde; above average rainfall. Best establishment (8 to 31 plants/m2 in the 1990 experiment) occurred in response to 166 mm in 12 rain days over a 29 day period in December-January 1990-91, followed by 10 dry days and then a further 60 mm of rain in February; plants flowered by May and thus survived winter well. Under non-flood conditions (1987, 1988 and 1990 experiments) the order of magnitude of establishment was: C. ciliaris, A. lappacea > S. incrassata > P. coloraturn. Under flood conditions (1989 experiment) establishment of S. incrassata was highest and that of A. lappacca was lowest. In the 1987 and 1988 experiments full stubble (1.5 and 3.4 t/ha) did not improve the establishment of surface-sown grasses over that on low stubble (0.1 and 1.4 tlha). In the 1989 and 1990 experiments establishment was lower on full stubble (5 and 7 tlha) than on low stubble (0.1 and 0.1 tlha) owing to, respectively, flooding and competition from volunteer wheat. After the six months establishment period grass density declined over the two to five year survival period with plants self- thinning due to interspecific competition. Allowing mature plants to seed increased plant density due to seedling recruitment under favourable climatic conditions.
Land Condition in the Tropical Tallgrass Pasture Lands. 1. Effects on Herbage Production.
Authors: Mcivor John G. , Ash Andrew J. , Cook Garry D.
Published: December 2005

A quantitative condition index based on vegetation (botanical composition and basal area of perennial grasses) and soil characteristics (erodibility, nutrient status and availability, partitioning of rainfall into infiltration and run-off) was developed for tropical tallgrass pastures near Charters Towers (north-east Queensland) and Katherine (Northern Territory). Herbage growth and the responses of individual species at 10 sites over two growing seasons were related to the index. At all sites there were significant linear relationships between herbage growth and condition index although the values differed between sites. Annual grasses increased and most perennial grasses decreased as condition declined but Bothriochloa pertusa and Bothriochloa ewartiana were most abundant at intermediate condition levels. The response of Chrysopogon fallax varied widely between sites. The lower herbage production on poor condition sites will result in lower carrying capacity.
Diet of the red fox (Vulpes vulpes) in south-western Queensland.
Authors: Palmer RA
Published: December 2005

Examination of the stomach contents of 74 foxes from a south-western Queensland sheep grazing property revealed a diverse range of prey. Mammals formed the bulk of the diet representing 64% of the total weight of food items and occurred in 80% of stomachs. Sheep and kangaroo carrion were the main mammalian prey. Insects and other invertebrates were an important but lesser component of the diet. Dietary trends were heavily influenced by human activity, rainfall, and season. These results differ from those of other studies conducted in southern parts of Australia due to the large proportions of scavenged food items in the diet (63% by weight) and relatively high consumption levels of non-mammalian prey. The lack of a small to medium sized staple prey source in the study area, which were available in southern areas appears to be the reason for the foxes reliance on such a varied prey base.
Do Australian Sheep Blowflies, Lucilia Cuprina (Diptera: Calliphoridae), Breed in Either Goat or Sheep Carcasses in a Semi-Arid Environment?
Authors: Cook DF , Steiner EC , Watson I , Dadour IR
Published: December 2005

Feral goat and sheep carcasses were exposed to insect attack on semi-arid pastoral land each month for one year. The native calliphorids Chrysomya rujifacies and Ch. varipes were by far the most abundant species de.veloping in virtually all carcasses. Sheep blowflies (L. cuprina) were incapable of developing from egg to adult on either feral goat or sheep carcasses during any month. Bush flies (Musca vetustissima) emerged from both feral goat and sheep carcasses from January to May, particularly from the gut contents. Chrysomya species were trapped in all months except June, whereas L. cuprina adults were only trapped from September to December. L. cuprina and Ch. rujifacies adults are very similar in appearance, hence many pastoralists assume that green blowflies on feral goat carcasses are sheep blowflies. However, this study clearly shows that L. cuprina are unable to complete their life cycle on either feral goat or sheep carcasses in the semi-arid environment of Carnarvon, Western Australia.
Identity, Lifestyle and Survival: Value Orientations of South Australian Pastoralists.
Authors: Holmes JH , Day P
Published: December 2005

Australia's rangelands are experiencing a rapid shift from dominantly commodity values towards a mix of commodity and (broadly defined) amenity values. The former hegemony of pastoralism is now being displaced by a diverse array of resource uses, strongly influenced by national aspirations concerning Aboriginal land rights, preservation of biodiversity and of valued semi-natural landscapes, sustainable management, tourism and recreation. This diversification in resource value is fostered by the highly differentiated value-orientations of influential interest-groups, including Aboriginals, welfarists, conservationists, pastoralists and a disparate array of tourists and recreationists. Simplistic modes of resource allocation are being replaced by complex, often contradictory modes of politicised decision-making, shaped by the demands of interest-groups, with decisions being focussed more on values than on facts. Accordingly, more effort needs to be spent in developing an understanding of value-orientations and their influence on the perceptions, needs and expectations of these various groups. A postal survey of 67 South Australian pastoralists reveals that they comprise a cohesive reference group with a strong sense of identity and self-worth. They closely identify with their distinctive way-of-life and its equally distinctive (and challenging) environment. They are very conscious of their role, not only as producers, but also as custodians of the rangelands, capable of making the pivotal decisions towards sustainable management. Their strong orientation towards intrinsic, expressive and social values provides partial compensation for continuing economic and social hardships. Above all they place high value on their independence, and they regard intervention by conservationists, urban interests, Aboriginal interests and governments as presenting a greater threat to their future than does prospective further economic decline. This distinctive value orientation has for long proved highly adaptive in ensuring survival in periods of economic and environmental stress, but may be less effective in meeting emerging challenges in which pastoralism has to adjust to a more complex decision context, in which other interest groups have values and goals markedly at variance with those held by pastoralists.
The Impact of Herbivores on Regeneration in Four Trees From Arid Australia.
Authors: Auld TD
Published: December 2005

The size distributions of populations of four semi-arid perennial trees were investigated within Kinchega National Park in western NSW. For Acacia ligulata, A, loderi and Alectryon oleifolius, it appears that regeneration has been eliminated or at best severely limited at most sites. Some regeneration has occurred through recruitment of vegetative suckers in Casuarina pauper. Currently these vegetative recruits have high survival rates under both rabbit and kangaroo grazing, although such grazing frequently reduces the height of vegetative suckers back to ground level. Survival of seedlings of Acacia ligulata was very limited, with highest survival when mammals were excluded. There was no survival of seedlings of Casuarina pauper in the presence of rabbits and survival was poor when rabbits were excluded. Many seedlings of both species die through desiccation. The survival data from seedlings and vegetative suckers reinforce the patterns observed in the size distribution of populations. Within Kinchega National Park, control of rabbits is essential to initiate regeneration. A reduction in the total grazing pressure (especially rabbits, sheep, cattle and goats) is necessary in critical dry periods on semi-arid and arid grazing land if regeneration of perennials is to be encouraged.
The Potential of Some Mechanical Treatments for Rehabilitating Arid Rangelands I. Within-Site Effects and Economic Returns.
Authors: Friedel MH , Kinloch JE , Muller WJ
Published: December 2005

Attempts to rehabilitate degraded arid rangelands do not always succeed, and we perceived a need for
some simple ecological indicators which would help determine whether mechanical intervention was
likely to be useful. In this first of two papers, we largely focus on the effect of pitting and opposed
discing, although we consider ripping and exclosure briefly, at 26 locations in central Australia.
Pits and furrows successfully trapped erosion products and supported more basal cover and a greater
number of plants than inter-furrow mounds or untreated areas. In addition, a number of soil variables
were altered by the treatments. However, economic returns were unlikely to exceed outlays in most of
the cases we considered. The best returns are predicted where degradation is minor, where livestock
are of high quality and where landholders collect their own seed. Exclusion of grazing in the initial
stages will enhance the amount of plant cover.
A Decision Support Approach to Sustainable Grazing Management for Spatially Heterogeneous Rangeland Paddocks.
Authors: Bellamy JA , Lowes D , Ash AJ , Mcivor JG , Macleod ND
Published: December 2005

Public concern for the way land resources are used has led to the introduction of legislation in several Australian States requiring the demonstration of sustainable use of the pastoral resource. However, no practical system of appraisal of sustainability in grazing management systems exists. The common situation facing decision-makers at policy and enterprise levels is one of inadequate, unobtainable or inappropriate data, or systematic indeterminacy. This necessitates erring on the side of caution, through an adaptive integrated approach to decision-making. Such an approach requires: (i) an understanding of the key processes that govern the interactions between livestock, plants, and heterogeneous landscape systems; (ii) the identification of indicators of potential problems in these systems at spatial and temporal scales relevant to human use and management; and (iii) the availability of effective tools to evaluate management options in terms of their risks to the sustainability of the grazing land resource, and the profitability of production. This paper describes a decision support approach to improving our understanding of the complexities of grazing management systems. The paper first proposes an integrated framework for a decision support system (DSS) for evaluating the sustainability of grazing management in terms of the risk of changes to the vegetation and soil resource, and the profitability of production. It then examines an application of a DSS approach, called Landassess DSS, to the tropical woodlands in northern Australia, and discusses the broader implications for sustainable management of extensive native pasture livestock production systems.
Building Grass Castles: Integrating Ecology and Management of Australia's Tropical Tallgrass Rangelands.
Authors: Ash AJ , Mcivor JG , Mott JJ , Andrew MH
Published: December 2005

The tropical tallgrass rangelands of Australia are declining in condition in response to increased grazing pressure. However, large areas are still in good condition and many of the deteriorated areas are not yet irreversibly damaged. Increases in grazing pressure have been associated with the loss of perennial grasses, woody weed invasion, and increased run-off and soil loss in some areas. The population dynamics, diet selection patterns, defoliation responses of the perennial grasses and impacts of fire are outlined and ways this understanding can be incorporated into management are presented. The perennial grasses are sensitive to defoliation and can only be lightly utilised. Annual utilisation rates should not exceed 25% in areas of moderate and high fertility and this threshold 'safe' level decreases to 15% on infertile soils in the monsoon zone of the north and north-west. Spelling pastures during the wet season, when they are particularly sensitive to defoliation, may enable utilisation during the rest of the year to be increased. Such a grazing regime allows fuel accumulation, increasing the opportunity for use of fire in managing exotic woody weeds and the treetshrub layer. Fire can also be used to improve animal distribution and reduce the formation of patches which are prone to soil degradation. Sown pastures and tree clearing can be used to increase carrying capacity and improve flexibility in the management of native pastures but careful consideration needs to be given to these improvements to prevent problems such as salinisation and unwanted spread of exotic pasture plants. One of the difficulties in developing recommendations relevant to management is that most of the ecological understanding is at the plant and plant community scale but most problems occur at the paddocWlandscape scale where our knowledge base is limited. Future work should focus at this large spatial scale so that ecological principles derived from a range of scales can be better integrated into guidelines more appropriate to extensive management of tropical tallgrass rangelands. Key words: grazing, population dynamics, defoliation, diet selection, fire, grass decline
Fire Studies in Mallee (Eucalyptus Spp.) Communities of Western New South Wales: Reptile and Beetle Populations in Sites of Differing Fire History.
Authors: Schlesinger CA , Noble JC , Weir T
Published: December 2005

Reptile and terrestrial beetle populations were sampled within adjoining mallee communities of similar botanical composition, but differing in fire history and vegetation structure. Studies were aimed at determining whether there were any major differences between faunal communities in sites with different fire histories. While the number of beetle species captured was significantly higher in the two most recently burnt sites, overall abundance of beetles did not differ significantly between various fire histories. Captures of Carenurn interiove were highest in a site burnt seven years prior to the study whereas captures of Tvichocarenum sp. were most common in the two most recently burnt areas. The number of reptile species captured did not differ significantly between sites but the relative abundance of nocturnal and diurnal reptiles was found to be significantly related to time since last fire. The number of geckos captured at the oldest fire site (burnt 18 years earlier) were significantly fewer than at the more recently burnt sites whereas captures of diurnal lizards did not differ. These patterns of reptile abundance are consistent with those found in other fire studies undertaken in similar habitats. This preliminary study confirms that both reptiles and beetles may be usefully incorporated in future management systems designed to monitor biological diversity in mallee ecosystems. Key words: fire, mallee, porcupine grass, nocturnal and diurnal reptiles and beetles
Implications of Spatio-Temporal Variation in Forage Production and Utilization for Animal Productivity in Extensive Grazing Systems.
Authors: Roshier DA , Nicol HI
Published: December 2005

In this paper we examine patterns of utilisation at the level of individual plants and forage availability at the paddock scale on five commercial sheep grazing properties that all experienced drought during the course of the study. Specifically, patterns of forage availability and pasture utilisation in large paddocks are examined against the assumptions of established models of animal productivity and grazing management practice. Forage resources in the rangelands can have dynamics independent of stock density and are not distributed evenly in time or space. Therefore, the extrapolation of known plant-animal interactions across scales is questionable and it is yet to be demonstrated how measures of animal productivity on small trial paddocks relate to production outcomes in large paddocks. A model is proposed for understanding animal production outcomes that incorporates variation in both pasture biomass and stock density. The scales, both spatial and temporal, at which pastoralists and scientists integrate ecological and animal productivity information usually differ. The understanding that each holds of the processes that limit animal productivity and the relationships between different elements of the production system is a product of the perspective from which they view the system. It is concluded that the difference between the 'scale of exploitation' and the scale at which heterogeneity is sufficient for survival of livestock is probably crucial to determining animal production outcomes in grazing systems subject to a high degree of temporal variation in forage availability. In these systems it seems reasonable to suggest that grazing experiments that vary the 'spatial scale of exploitation' while maintaining stock density constant may give as many insights into the limitations on animal productivity as the more typical experiment that only varies stock density. Key words: grazing models, animal productivity, heterogeneity, scale, utilisation, forage availability, stocking rates.
Rangelands in a Planetist Future.
Authors: Ellyard P
Published: December 2005

On the threshold of the new millennium the world is being changed by the combined forces of globalisation, tribalisation and technological change. A new interdependent planetary society is emerging. This paper describes the nature of this emerging planetary society, the forces which are creating it, and a new paradigm called Planetism which will accompany its birth. The values of Planetism, the values of the 'Spaceship Culture', will dominate by about the year 2020, and will shape the global market place of the early 21st century. The development of Planetism is slowly replacing the Modernist culture which has dominated most of the 20th century. While the urban areas have mostly moved on to Planetism, the cosmonaut culture, most of our rangelands are still dominated by Modernism, the Cowboy Culture. However, every year there are more cosmonauts and fewer cowboys. If we are to improve effective communication between the city and the bush over the management of rangelands, it is important to understand the mindsets of both the city and the bush. While there are cowboys in the city there is a much higher proportion of them in the bush. Much of the conflict over the rangelands is due to the fact that the city looks at the rangelands from a cosmonaut perspective, while the bush looks at the same rangelands from a largely cowboy perspective. Many people in the rangelands see themselves as making a stand against rampant cosmonautisation. Many of the cowboys of the rangelands are still locked into the old modernist mindset, based on the superiority of western values, culture, science and technology and an endlessly expanding frontier. The city has moved on into Post Modernism and is busy synthesising values from a wide range of cultures other than the western dominant culture. The outcome of this synthesis will be Planetist. The people of the cities have become interested in the culture of the Australian Aborigine, whereas those in the bush, while mindful of this culture tend to still look at it with a paternalist and Modernist mindset. The global adoption of the Spaceship Culture and of its paradigm, Planetism, is both inevitable and desirable. We need to adopt processes to reconcile the city and the bush by easing the bush into the world of the cosmonaut, while reassuring the bush that these changes are necessary and are not necessarily threatening. Those in the bush who are taking Custer's Last Stand against perceived threats such as Wik need to be reassured that the future is not so bleak. The dominant mindsets of the bush leadership is engendering a bleak cowboy 'battlers' outlook. While these mindsets persist, reconciliation of city and bush will be difficult. Key words: Modernism, Planetism, cosmonaut, cowboy, indigenous
Comparison of Surveys of Kangaroos in Queensland Using Helicopters and Fixed-Wing Aircraft.
Authors: Pople AR , Cairns SC , Clancy TF , Grigg GC , Beard LA , Southwell CJ
Published: December 2005

Kangaroo harvest quotas for each Australian state have been set mainly as proportions of population estimates derived from aerial surveys. Estimating population size from strip transect counts using fixed- wing aircraft has become an established technique, but counts must be adjusted by correction factors to ensure population estimates are both accurate and repeatable. Surveys of kangaroos in Queensland are currently conducted with helicopters using line transect methodology, but cost restricts their use to relatively small survey blocks. Nevertheless, they return more accurate and repeatable estimates of kangaroo density than surveys with fixed-wing aircraft. A comparison of the above two techniques was made along the same transect lines in seven survey blocks (5000-10,000 km2) in southern and western Queensland, allowing an assessment of the comparative accuracy of the fixed-wing method. For red kangaroos (Macropus rufus), required correction factors of 0.7-3.1 were similar to those used previously. However, for eastern grey kangaroos (M. giganteus), substantially larger correction factors of 3.4-10.2 were needed to approach true density. For wallaroos (M. robustus), correction factors of 3.8-4.8 were required, but can be considered conservative because helicopter-derived density estimates are known to be underestimated by a factor of 2-3. Further work is needed to establish how correction factors for each species should be applied on a broader scale and whether they lead to repeatable estimates of kangaroo density. Key words: aerial survey, line transect, correction factors, strip transect, wallaroo.
Climate Change in Queensland's Grazing Lands. I. Approaches and Climatic Trends.
Authors: Mckeon GM , Hall WB , Crimp SJ , Howden SM , Stone RC , Jones DA
Published: December 2005

Climate change is an important global issue but is yet to be recognised as such by many rangelands users. This paper reviews some of the uncertainties relating to pre-instrumental and future climate change and documents current trends and fluctuations in climate of Queensland's grazing lands. Analysis of daily climate surfaces for Queensland's pastoral/cropping zone shows high variability in annual rainfall which is influenced by the El NiHo-Southern Oscillation (ENSO) phenomenon. This relationship, when examined using moving windows, has changed during this century with the 1930-40s being a period of low correlation. Minimum temperatures taken from the climate surfaces also changed, showing a significant (P<0.01) increase over time especially in May. Over the 40 years since 1957, annual minimum temperatures have increased by l.0�C for the pastoral/cropping zone and coastal sub-zone, winter minimum temperatures by 1.2�C for the pastoral/cropping zone (1.3�C for the coastal sub-zone), summer minimum temperatures by 0.7�C for the pastoral/cropping zone and coastal sub-zone, and May minimum temperatures by 2.8�C for the pastoral/cropping zone (3.0�C for the coastal sub-zone). Consistent significant trends in vapour pressure (increasing, P<0.001) and solar radiation (decreasing, P<0.05) also occurred in May. The mechanisms for the identified climate trends and unusual behaviour of ENS0 are the subject of speculation with attribution of causes to natural variability or the enhanced greenhouse effect being unresolved. Continued monitoring of these trends and fluctuations will be important for the future management of Queensland's grazing lands with this analysis highlighting the need for discrimination of trends from natural variability. In terms of grazing management and degradation processes, this work also highlights that general changes in climate averages may disguise important variation at yearly and decadal time scales.
Establishing Native Grasses in Degraded Pastures of Central Western New South Wales.
Authors: Semple WS , Koen TB , Cole IA
Published: December 2005

Renewed interest in native grasses in recent years has led to the release of a small number of cultivars but for most native species, seed is only available from wild stands. Seed can be harvested with a brush harvester but cleaning seed to a level that will allow it to pass through conventional sowing equipment is often difficult. Techniques for successful field establishment of native species are still not fully understood. From 1993 to 1995, native grasses (mainly warm-season types) were sown in early spring in exotic pastures at a number of sites in the Central West of NSW. Various seedbed types, sowing methods and species were evaluated in six experiments. In five of the experiments, establishment was low for most species - a result attributed primarily to weed competition. At one site in 1994, however, the combination of a cultivated seedbed, 18 months of pre-sowing weed control, relatively low soil fertility and a high sowing rate resulted in high emergence of most species and acceptable survival of Paspalidium jubi$orum, Themeda australis and to a lesser extent, Chloris ventricosa and C. truncata. Key words: exotic species, native species, emergence, survival, seedbed, weed control.
Bordetellafilamentous hemagglutinin plays a critical role in immunomodulation, suggesting a mechanism for host specificity
Authors: Inatsuka Carol S. , Julio Steven M. , Cotter Peggy A.
Published: December 2005

Bordetella pertussis, the causative agent of the acute childhood respiratory disease whooping cough, is a human-adapted variant ofBordetella bronchiseptica, which displays a broad host range and typically causes chronic, asymptomatic infections. These pathogens express a similar but not identical surface-exposed and secreted protein called filamentous hemagglutinin (FHA) that has been proposed to function as both a primary adhesin and an immunomodulator. To test the hypothesis that FHA plays an important role in determining host specificity and/or the propensity to cause acute versus chronic disease, we constructed aB. bronchisepticastrain expressing FHA fromB. pertussis(FHABp) and compared it with wild-typeB. bronchisepticain several natural-host infection models. FHABpwas able to substitute for FHA fromB. bronchiseptica(FHABb) with regard to its ability to mediate adherence to several epithelial and macrophage-like cell linesin vitro, but it was unable to substitute for FHABbin vivo. Specifically, FHABb, but not FHABp, allowedB. bronchisepticato colonize the lower respiratory tracts of rats, to modulate the inflammatory response in the lungs of immunocompetent mice, resulting in decreased lung damage and increased bacterial persistence, to induce a robust anti-Bordetellaantibody response in these immunocompetent mice, and to overcome innate immunity and cause a lethal infection in immunodeficient mice. These results indicate a critical role for FHA inB. bronchiseptica-mediated immunomodulation, and they suggest a role for FHA in host specificity.
Cellular basis of urothelial squamous metaplasia
Authors: Liang Feng-Xia , Bosland Maarten C. , Huang Hongying , Romih Rok , Baptiste Solange , Deng Fang-Ming , Wu Xue-Ru , Shapiro Ellen , Sun Tung-Tien
Published: December 2005

Although the epithelial lining of much of the mammalian urinary tract is known simply as the urothelium, this epithelium can be divided into at least three lineages of renal pelvis/ureter, bladder/trigone, and proximal urethra based on their embryonic origin, uroplakin content, keratin expression pattern, in vitro growth potential, and propensity to keratinize during vitamin A deficiency. Moreover, these cells remain phenotypically distinct even after they have been serially passaged under identical culture conditions, thus ruling out local mesenchymal influence as the sole cause of their in vivo differences. During vitamin A deficiency, mouse urothelium form multiple keratinized foci in proximal urethra probably originating from scattered K14-positive basal cells, and the keratinized epithelium expands horizontally to replace the surrounding normal urothelium. These data suggest that the urothelium consists of multiple cell lineages, that trigone urothelium is closely related to the urothelium covering the rest of the bladder, and that lineage heterogeneity coupled with cell migration/replacement form the cellular basis for urothelial squamous metaplasia.
Repair of double-strand breaks by nonhomologous end joining in the absence of Mre11
Authors: Di Virgilio Michela , Gautier Jean
Published: December 2005

Mre11–Rad50–Nbs1 (MRN) complex involvement in nonhomologous end joining (NHEJ) is controversial. The MRN complex is required for NHEJ in Saccharomyces cerevisiae but not in Schizosaccharomyces pombe. In vertebrates, Mre11, Rad50, and Nbs1 are essential genes, and studies have been limited to cells carrying hypomorphic mutations in Mre11 or Nbs1, which still perform several MRN complex–associated activities. In this study, we analyze the effects of Mre11 loss on the mechanism of vertebrate NHEJ by using a chromatinized plasmid double-strand break (DSB) repair assay in cell-free extracts from Xenopus laevis. Mre11-depleted extracts are able to support efficient NHEJ repair of DSBs regardless of the end structure. Mre11 depletion does not alter the kinetics of end joining or the type and frequency of junctions found in repaired products. Finally, Ku70-independent end-joining events are not affected by Mre11 loss. Our data demonstrate that the MRN complex is not required for efficient and accurate NHEJ-mediated repair of DSBs in this vertebrate system.
Nesprin-3, a novel outer nuclear membrane protein, associates with the cytoskeletal linker protein plectin
Authors: Wilhelmsen Kevin , Litjens Sandy H.M. , Kuikman Ingrid , Tshimbalanga Ntambua , Janssen Hans , van den Bout Iman , Raymond Karine , Sonnenberg Arnoud
Published: December 2005

Despite their importance in cell biology, the mechanisms that maintain the nucleus in its proper position in the cell are not well understood. This is primarily the result of an incomplete knowledge of the proteins in the outer nuclear membrane (ONM) that are able to associate with the different cytoskeletal systems. Two related ONM proteins, nuclear envelope spectrin repeat (nesprin)–1 and –2, are known to make direct connections with the actin cytoskeleton through their NH2-terminal actin-binding domain (ABD). We have now isolated a third member of the nesprin family that lacks an ABD and instead binds to the plakin family member plectin, which can associate with the intermediate filament (IF) system. Overexpression of nesprin-3 results in a dramatic recruitment of plectin to the nuclear perimeter, which is where these two molecules are colocalized with both keratin-6 and -14. Importantly, plectin binds to the integrin α6β4 at the cell surface and to nesprin-3 at the ONM in keratinocytes, suggesting that there is a continuous connection between the nucleus and the extracellular matrix through the IF cytoskeleton.
Subcellular targeting of oxidants during endothelial cell migration
Authors: Wu Ru Feng , Xu You Cheng , Ma Zhenyi , Nwariaku Fiemu E. , Sarosi George A. , Terada Lance S.
Published: December 2005

Endogenous oxidants participate in endothelial cell migration, suggesting that the enzymatic source of oxidants, like other proteins controlling cell migration, requires precise subcellular localization for spatial confinement of signaling effects. We found that the nicotinamide adenine dinucleotide phosphate reduced (NADPH) oxidase adaptor p47phox and its binding partner TRAF4 were sequestered within nascent, focal complexlike structures in the lamellae of motile endothelial cells. TRAF4 directly associated with the focal contact scaffold Hic-5, and the knockdown of either protein, disruption of the complex, or oxidant scavenging blocked cell migration. An active mutant of TRAF4 activated the NADPH oxidase downstream of the Rho GTPases and p21-activated kinase 1 (PAK1) and oxidatively modified the focal contact phosphatase PTP-PEST. The oxidase also functioned upstream of Rac1 activation, suggesting its participation in a positive feedback loop. Active TRAF4 initiated robust membrane ruffling through Rac1, PAK1, and the oxidase, whereas the knockdown of PTP-PEST increased ruffling independent of oxidase activation. Our data suggest that TRAF4 specifies a molecular address within focal complexes that is targeted for oxidative modification during cell migration.
Analysis of the intraclonal diversity of HLA‐A0201‐restricted T lymphocyte epitopes in follicular lymphoma idiotype
Authors: Molinier‐Frenkel Valérie , Popa Natalia , Poulot Virginie , Chaise Coralie , Marquet Jeanine , Haioun Corinne , Gaulard Philippe , Farcet Jean‐Pierre , Delfau‐Larue Marie‐Hélène
Published: December 2005

Lymphoma‐derived immunoglobulin idiotype (Id) is a tumour‐specific antigen used for antitumour vaccination in follicular lymphoma (FL). However, FL Ids are subject to hypermutation and subclones may escape antitumour cytotoxic T‐cell response. To investigate the intraclonal epitope diversity, we sequenced the FL heavy chain gene (consensus Id gene) and subclones of 24 patients. The derived polypeptide sequences were analysed by bioinformatics for human leucocyte antigen (HLA)‐A0201‐restricted epitope prediction. Epitopes were classified according to BIMAS and SYFPEITHI scores. Surprisingly in these highly mutated polypeptides, the epitopes concentrated in short hotspots in the conserved framework regions (FRs), both in HLA‐A0201+ and HLA‐A0201− patients. Similar hotspots have been observed by others in chronic lymphocytic leukaemia Ids which in contrast to FL have low mutation frequency. FR3 amino acids 78–88 displayed the best‐score epitopes in Ids containing a VH3‐family segment, the most represented in FL Ids. Such VH3‐FR378−88 epitopes were previously demonstrated as immunogenic. Modifications of the epitope pattern in subclones of HLA‐A0201+ patients were generally absent from high‐score peptides, including VH3‐FR378−88 epitopes (83% unmodified). Therefore, no tendency for loss of HLA‐A0201‐restricted epitopes was evidenced and, given their limited intraclonal diversity, VH3‐FR378−88 epitopes may provide a useful target for the induction of cytotoxic response in Id‐vaccinated FL patients.
Arsenic trioxide (AT) is a novel human neutrophil pro‐apoptotic agent: effects of catalase on AT‐induced apoptosis, degradation of cytoskeletal proteins and de novo protein synthesis
Authors: Binet François , Cavalli Hélène , Moisan Éliane , Girard Denis
Published: December 2005

The anti‐cancer drug arsenic trioxide (AT) induces apoptosis in a variety of transformed or proliferating cells. However, little is known regarding its ability to induce apoptosis in terminally differentiated cells, such as neutrophils. Because neutropenia has been reported in some cancer patients after AT treatment, we hypothesised that AT could induce neutrophil apoptosis, an issue that has never been investigated. Herein, we found that AT‐induced neutrophil apoptosis and gelsolin degradation via caspases. AT did not increase neutrophil superoxide production and did not induce mitochondrial generation of reactive oxygen species. AT‐induced apoptosis in PLB‐985 and X‐linked chronic granulomatous disease (CGD) cells (PLB‐985 cells deficient in gp91phox mimicking CGD) at the same potency. Addition of catalase, an inhibitor of H2O2, reversed AT‐induced apoptosis and degradation of the cytoskeletal proteins gelsolin, α‐tubulin and lamin B1. Unexpectedly, AT‐induced de novo protein synthesis, which was reversed by catalase. Cycloheximide partially reversed AT‐induced apoptosis. We conclude that AT induces neutrophil apoptosis by a caspase‐dependent mechanism and via de novo protein synthesis. H2O2 is of major importance in AT‐induced neutrophil apoptosis but its production does not originate from nicotinamide adenine dinucleotide phosphate dehydrogenase activation and mitochondria. Cytoskeletal structures other than microtubules can now be considered as novel targets of AT.
Direct targeting of genetically modified tumour cells to FcγRI triggers potent tumour cytotoxicity
Authors: Bevaart Lisette , Goldstein Joel , Vitale Laura , Russoniello Christina , Treml John , Zhang Jun , Graziano Robert F. , Leusen Jeanette H. W. , van de Winkel Jan G. J. , Keler Tibor
Published: December 2005

Expression of the type I receptor for Fc domain of immunoglobulin (Ig)G (FcγRI or CD64) is restricted to myeloid effector cells, such as monocytes, macrophages and a subset of dendritic cells. Previous work has indicated a role for FcγRI in antibody‐dependent phagocytosis and lysis of tumour cells. We hypothesised that tagging of tumour cells with an anti‐FcγRI single chain Fv (sFv) may facilitate targeting to this receptor on effector cells, thereby initiating tumour cytotoxicity. A vector encoding the sFv for an FcγRI‐specific antibody (H22), linked to the transmembrane domain of platelet‐derived growth factor was constructed. Transfected tumour cells expressed high surface levels of functional H22‐sFv, which greatly enhanced susceptibility for phagocytosis and lysis by monocytes and macrophages. The expression of H22‐sFv evoked the ability of tumour cells to directly activate monocytes, as evidenced by phosphorylation of mitogen‐activated protein kinase and secretion of the inflammatory cytokines interleukin (IL)‐1β, tumour necrosis factor‐α and IL‐6. Moreover, growth of tumour cells in mice expressing H22‐sFv was profoundly delayed (or absent) in transgenic mice expressing human FcγRI. These results demonstrated that tumour cells can be readily modified to activate cell effector mechanisms, a strategy that may be useful for in vivo targeting in patients.
Changes in water quality during heating in electromagnetic and gas heated pans and the relationship between water quality changes and temperature increase rate
Authors: Sasaki Ken , Hiratsuka Hiroshi , Takeno Kenji
Published: December 2005

Relatively large changes in the indicators of water quality, such as pH, hardness, and bicarbonate content, were observed during electromagnetic heating of pans of different tap waters and compared with pans heated by liquid natural gas (LNG) or liquid petroleum gas (LPG). For example, the pH and hardness of Hiroshima tap water were increased from 7.35 to 9.27 and from 19.0 to 35.7 mg L−1, respectively, during 20 min of electromagnetic heating. When tap water from Tokyo was subjected to electromagnetic heating, the water hardness of 74.2 mg L−1 was increased by 52% after 20 min of heating. Such water quality changes were observed consistently in several tap water samples across Japan. These changes showed a close correlation with rates of temperature increase. It was suggested that mineral components (Ca and Mg), which were attached on the stainless steel surface of the pans might be released into the tap water with high calorific heating.
MHC gene configuration variation in geographically disparate populations of California sea lions (Zalophus californianus)
Authors: BOWEN L. , ALDRIDGE B. M. , DELONG R. , MELIN S. , GODINEZ C. , ZAVALA A. , GULLAND F. , LOWENSTINE L. , STOTT J. L. , JOHNSON M. L.
Published: December 2005

Major histocompatibility complex (MHC) class II DRB genotypes were examined in two geographically isolated populations of California sea lions (Zalophus californianus) (Gulf of California and California coastal Pacific Ocean). Genomic DNA from 227 California sea lions was examined using eight sequence‐specific primer (SSP) pairs flanking the putative peptide‐binding site. A total of 40 different Zaca‐DRB genotype configurations were identified among the 227 individuals. Using SSP‐PCR, significant differences were found between coastal California and Gulf of California Zalophus populations in numbers of DRB sequences per individual and configuration of sequences within individuals. Additionally, unique local patterns of MHC diversity were identified among the Midriff Island animals. These population differences are consistent with either ecologically distinct patterns of selection pressures and/or geographical isolation. The consequences of these partitioned MHC configurations at the population level are as yet unknown; however, the worldwide increase in emerging marine diseases lends urgency to their examination.