855 resultados para Western Algeria


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The ocellated angelshark, Squatina tergocellatoides, Chen, 1963 is redescribed from the holotype, which was thought to be lost. Its recent recovery has allowed for a revised description, including new data, and comparison to other Western Pacific squatinids. Squatina tergocellatoides can be distinguished from its congeners by three pairs of prominent large black spots, each with a diameter greater than eye length; two on each pectoral fin at anterior and posterior angles and one on each side near the tail base; another three pairs of lesser defined spots, one large spot on base of each dorsal fin and one located laterally on each side of tail located below first dorsal fin. Ventral surface is uniformly white to cream coloured, and margins of pectoral fins and tail similar in colour to dorsal side. Pectoral fins with angular lateral apices and rounded posterior lobe, pelvic fin tips not reaching origin of first dorsal fin, strongly fringed nasal barbels, small inter-orbital space, head and mouth lengths, broad internarial width and pelvic fin base, a very small pelvic girdle width, and a caudal fin with triangular ventral lobe greater in length than dorsal lobe. Comments on additional specimens are provided, as well as observations on biogeography. A review of western Pacific squatinids is also provided.

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Managing large variations in herbage production, resulting from highly variable seasonal rainfall, provides a major challenge for the sustainable management of Astrebla (Mitchell grass) grasslands in Australia. A grazing study with sheep was conducted between 1984 and 2010 on an Astrebla grassland in northern Queensland to describe the effects of a range of levels of utilisation of the herbage at the end of the summer growing season (April–May in northern Australia) on the sustainability of these grasslands. In unreplicated paddocks, sheep numbers were adjusted annually to achieve 0, 10, 20, 30, 50 and 80% utilisation of the herbage mass at the end of the summer over the ensuing 12 months. Higher levels of utilisation reduced both total and Astrebla spp. herbage mass because of the effects of higher utilisation on Astrebla spp. and this effect was accentuated by drought. The tussock density of Astrebla spp. varied widely among years but with few treatment differences until 2005 when density was reduced at the 50% level of utilisation. A major change in density resulted from a large recruitment of Astrebla spp. in 1989 that influenced its density for the remainder of the study. Basal area of the tussocks fluctuated among years, with increases due to rainfall and decreases during droughts. Seasonal rainfall was more influential than level of utilisation in changes to the basal area of perennial grasses. Drought resulted in the death of Astrebla spp. tussocks and this effect was accentuated at higher levels of utilisation. A series of three grazing exclosures were used to examine the recovery of the density and basal area of Astrebla spp. after it had been reduced by 80% utilisation over the preceding 9 years. This recovery study indicated that, although grazing exclusion was useful in the recovery of Astrebla spp., above-average rainfall was the major factor driving increases in the basal area of perennial grasses. Spring values of the Southern Oscillation Index and associated rainfall probabilities were considered to have potential for understanding the dynamics of Astrebla spp. It was concluded that Astrebla grassland remained sustainable after 26 years when grazed at up to 30% utilisation, while, at 50% utilisation, they became unsustainable after 20 years. Results from this study emphasised the need to maintain the population of Astrebla spp. tussocks.

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The occurrence of interstitial species in Astrebla grasslands in Australia are influenced by grazing and seasonal rainfall but the interactions of these two influences are complex. This paper describes three studies aimed at determining and explaining the changes in plant species richness and abundance of the interstitial species in a long-term sheep utilisation experiment in an Astrebla grassland in northern Queensland. In the first study, increasing utilisation increased the frequency of Dactyloctenium radulans (Button grass) and Brachyachne convergens (Downs couch) and reduced that of Streptoglossa adscendens (Mint bush). In the second study, seasonal rainfall variation between 1984 and 2009 resulted in large annual differences in the size of the seed banks of many species, but increasing utilisation consistently reduced the seed bank of species such as Astrebla spp. and S. adscendens and increased that of species such as B. convergens, D. radulans, Amaranthus mitchellii (Boggabri) and Boerhavia sp. (Tar vine). In the third study, the highest species richness occurred at the lightest utilisation because of the presence of a range of palatable forbs, especially legumes. Species richness was reduced as utilisation increased. Species richness in the grazing exclosure was low and similar to that at the heaviest utilisation where there was a reduction in the presence of palatable forb species. The pattern of highest species richness at the lightest grazing treatment was maintained across three sampling times, even with different amounts of seasonal rainfall, but there was a large yearly variation in both the density and frequency of many species. It was concluded that the maintenance of highest species richness at the lightest utilisation was not aligned with other data from this grazing experiment which indicated that the maximum sustainable wool production occurred at moderate utilisation.

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Being at the crossroads of the Old World continents, Western Asia has a unique position through which the dispersal and migration of mammals and the interaction of faunal bioprovinces occurred. Despite its critical position, the record of Miocene mammals in Western Asia is sporadic and there are large spatial and temporal gaps between the known fossil localities. Although the development of the mammalian faunas in the Miocene of the Old World is well known and there is ample evidence for environmental shifts in this epoch, efforts toward quantification of habitat changes and development of chronofaunas based on faunal compositions were mostly neglected. Advancement of chronological, paleoclimatological, and paleogeographical reconstruction tools and techniques and increased numbers of new discoveries in recent decades have brought the need for updating and modification of our level of understanding. We under took fieldwork and systematic study of mammalian trace and body fossils from the northwestern parts of Iran along with analysis of large mammal data from the NOW database. The data analysis was used to study the provinciality, relative abundance, and distribution history of the closed- and open-adapted taxa and chronofaunas in the Miocene of the Old World and Western Asia. The provinciality analysis was carried out, using locality clustering, and the relative abundance of the closed- and open-adapted taxa was surveyed at the family level. The distribution history of the chronofaunas was studied, using faunal resemblance indices and new mapping techniques, together with humidity analysis based on mean ordinated hypsodonty. Paleoichnological studies revealed the abundance of mammalian footprints in several parts of the basins studied, which are normally not fossiliferous in terms of body fossils. The systematic study and biochronology of the newly discovered mammalian fossils in northwestern Iran indicates their close affinities with middle Turolian faunas. Large cranial remains of hipparionine horses, previously unknown in Iran and Western Asia, are among the material studied. The initiation of a new field project in the famous Maragheh locality also brings new opportunities to address questions regarding the chronology and paleoenvironment of this classical site. Provinciality analysis modified our previous level of understandings, indicating the interaction of four provinces in Western Asia. The development of these provinces was apparently due to the presence of high mountain ranges in the area, which affected the dispersal of mammals and also climatic patterns. Higher temperatures and possibly higher co2 levels in the Middle Miocene Climatic Optimum apparently favored the development of the closed forested environments that supported the dominance of the closed-adapted taxa. The increased seasonality and the progressive cooling and drying of the midlatitudes toward the Late Miocene maintained the dominance of open-adapted faunas. It appears that the late Middle Miocene was the time of transition from a more forested to a less forested world. The distribution history of the closed- and open-adapted chronofaunas shows the presence of cosmopolitan and endemic faunas in Western Asia. The closed-adapted faunas, such as the Arabian chronofauna of the late Early‒early Middle Miocene, demonstrated a rapid buildup and gradual decline. The open-adapted chronofaunas, such as the Late Miocene Maraghean fauna, climaxed gradually by filling the opening environments and moving in response to changes in humidity patterns. They abruptly declined due to demise of their favored environments. The Siwalikan chronofauna of the early Late Miocene remained endemic and restricted through all its history. This study highlights the importance of field investigations and indicates that new surveys in the vast areas of Western Asia, which are poorly sampled in terms of fossil mammal localities, can still be promising. Clustering of the localities supports the consistency of formerly known patterns and augments them. Although the quantitative approach to relative abundance history of the closed- and open-adapted mammals harks back to more than half a century ago, it is a novel technique providing robust results. Tracking the history of the chronofaunas in space and time by means of new computational and illustration methods is also a new practice that can be expanded to new areas and time spans.

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A disease outbreak investigation was conducted in western Queensland to investigate a rare suspected outbreak of pyrrolizidine alkaloid (PA) toxicosis in horses. Thirty five of 132 horses depastured on five properties on the Mitchell grass plains of western Queensland died in the first six months of 2010. Clinical–pathological findings were consistent with PA toxicosis. A local variety of Crotalaria medicaginea was the only hepatotoxic plant found growing on affected properties. Pathology reports and departure and arrival dates of two brood mares provided evidence of a pre wet season exposure period. All five affected properties experienced a very dry spring and early summer preceded by a large summer wet season. The outbreak was characterised as a point epidemic with a sudden peak of deaths in March followed by mortalities steadily declining until the end of June. The estimated morbidity (serum IGG > 50 IU/L) rate was 76%. Average crude mortality was 27% but higher in young horses (67%) and brood mares (44%). Logistic regression analysis showed that young horses and brood mares and those grazing denuded pastures in December were most strongly associated with dying whereas those fed hay and/or grain based supplements were less likely to die. This is the first detailed study of an outbreak of PA toxicosis in central western Queensland and the first to provide evidence that environmental determinants were associated with mortality, that the critical exposure period was towards the end of the dry season, that supplementary feeding is protective and that denuded pastures and the horses physiological protein requirement are risk factors.

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Three new species of Tilletia are described from species of Eriachne (Poaceae) in the arid tropics of north-western Australia. In Western Australia, T. mactaggartii sp. nov. infects E. burkittii, and T. geeringii sp. nov. infects E. festucacea. Tilletia marjaniae sp. nov. infects E. pulchella subsp. dominii in Western Australia and the Northern Territory. These species are the first records of Tilletia on Eriachne. Phylogenetic relationships of these species were inferred from internal transcribed spacer of ribosomal RNA region and large subunit ribosomal RNA gene sequences.

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Teachers working in regional, rural and remote areas of Western Australia often experience a strong sense of geographic and social isolation from peers, colleagues and appropriate support mechanisms due to the huge distances between towns and communities. The projects described here have focused on the use of technology to enhance both teacher and student learning; and assist with Indigenous education and teacher professional learning. Connecting and collaborating through technologies is emerging as a powerful tool for motivating and engaging both teachers and learners within schools. Coupled with the direction of the current Federal Government with the Digital Education Revolution and the Digital Regions initiatives, opportunities for better serving regional, rural and remote communities are discussed, as are some of the current issues and needs related to these schools in Western Australia. The scope of these projects has been such that three guiding principles have been implemented through contextual lenses of varying foci - at the level of an individual, a school, and a community.

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In 2010 a group of teacher educators from four universities, experienced in rural and remote education, formed the Tertiary Educators Rural, Regional and Remote Network (TERRR Network). The collaborative goal was to improve the quality of graduates taking appointments beyond the metropolitan areas of Western Australia. The TERRR Network developed a research project to improve the capacity of universities to prepare teachers for employment in rural and remote locations. A range of outcomes emerged from the project, including: 1) the development of seven rural and remote-oriented curricula modules linked to the Australian Professional Standards for Teachers; 2) a cross-institutional field experience, and; 3) the development of a community of practice involving the Department of Education, universities and schools to address the logistical implications of placing pre-service students in rural and remote locations. This paper reports on the five phases of the project design, with a focus on learning in the field and concludes with reflections on the collaborative process used by the four universities in order to ensure that research evidence informs future policy and program development.

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This paper reports on outcomes of Phases One and Two of the ALTC Competitive Research and Development Project "Developing Strategies at the Pre-Service Level to Address Critical Teacher Attraction and Retention Issues in Australian Rural, Regional and Remote Schools." This project funded over two years aims to strengthen the capacity and credibility of universities to prepare rural, regional and remote educators, similar to the capacity and credibility that has been created in preparing Australia's rural, regional and remote health workers. There is a strong recognition of the fundamental importance of quality teaching experiences rural, regional and remote schools and throughout this project over 200 pre-service teachers have participated in a curriculum module/object and completed a survey that encourages them to consider teaching in regional Western Australia. The project has mapped current Western Australian rural, regional and remote pre-service teacher education curriculum and field experience model. This mapping completed a comparison of national information with the identification of rural, regional and remote education curriculum and/or field experience models used nationally and internationally. In particular results from Phase One and Two will be presented reporting on the findings of the first year of the project.

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Access to quality professional learning and the opportunity to collaborate with other educators can be limited for teachers in rural and remote areas of Western Australia. A recognised need to enhance the skills of rural teaching professionals and encourage teachers in small communities to join collegial networks was established by the members of several professional organisations. A working group consisting of representatives from the Australian College of Educators-WA (ACE-WA), the Rural and Remote Education Advisory Council (RREAC), the Society for the Provision of Education in Rural Australia (SPERA) and the School of Isolated and Distance Education (SIDE) provided teachers in rural areas with the opportunity to reduce professional isolation through the provision of relevant, convenient, and cost effective in-service education. Through a videoconferencing system, accessed within the Western Australian Telecentre Network and other educational organisations, the audience connected and participated with the presenter and studio based audience for two Hot Topics Seminars in 2008. This paper reports on the challenges and successes encountered by the working group and the findings of the research conducted throughout 2008.