1,721,360 research outputs found
Freshwater Sawfish (Pristis microdon) movements and population demographics in the Fitzroy River, Western Australia and genetic analysis of P. microdon and Pristis zijsron
Full text linkThis report is a continuation of the study that was presented to the DEWHA in 2008 entitled:
Whitty, J.M., Phillips, N.M., Morgan, D.L., Chaplin, J.A., Thorburn, D.C. & Peverell, S.C. (2008). Habitat associations of Freshwater Sawfish (Pristis microdon) and Northern River Shark (Glyphis sp. C): including genetic analysis of P. microdon across northern Australia. Centre for Fish & Fisheries Research, Murdoch University report to Australian Government, Department of the Environment, Water, Heritage and the Arts
Human forearm position sense after fatigue of elbow flexor muscles
No full textAfter a period of eccentric exercise of elbow flexor muscles of one arm in young, adult human subjects, muscles became fatigued and damaged. Damage indicators were a fall in force, change in resting elbow angle and delayed onset of soreness. After the exercise, subjects were asked to match the forearm angle of one arm, whose position was set by the experimenter, with their other arm. Subjects matched the position of the unsupported reference arm, when this was unexercised, with a significantly more flexed position in their exercised indicator arm. Errors were in the opposite direction when the reference arm was exercised. The size of the errors correlated with the drop in force. Less consistent errors were observed when the reference arm was supported. A similar pattern of errors was seen after concentric exercise, which does not produce muscle damage. The data suggested that subjects were using as a position cue the perceived effort required to maintain a given forearm angle against the force of gravity. The fall in force from fatigue after exercise meant more effort was required to maintain a given position. That led to matching errors between the exercised and unexercised arms. It was concluded that while a role for muscle spindles in kinaesthesia cannot be excluded, detailed information about static limb position can be derived from the effort required to support the limb against the force of gravity
Baseline study on the fish and freshwater crayfish fauna in the Blackwood River and its tributaries receiving discharge from the Yarragadee Aquifer
Full text linkWater from the Yarragadee Aquifer surfaces in Poison Gully and Milyeannup Brook, and maintains flow in these Blackwood River tributaries throughout the year. It also enters Layman Brook during winter and spring, yet this stream dries during summer. The aim of this study was to provide baseline information on the fish and freshwater crayfish fauna in these Yarragadee aquifer-fed tributaries, and compare them to both those upstream tributaries devoid of any flow from the aquifer, and those tributaries entering the Blackwood River immediately downstream of the aquifer discharge area. A comparison was also made of the fish fauna of the Blackwood River main channel that receives flow from the Yarragadee Aquifer to a number of main channel sites upstream of the discharge area, i.e. main channel sites that do not receive any flow from the Yarragadee.
There was a significant difference between the fish fauna associated with main channel sites when compared to tributaries and there were substantial differences in the fauna of the downstream and upstream main channel sites. Main channel sites downstream of the Yarragadee Aquifer discharge area had a much higher diversity of fish and freshwater crayfish than main channel sites upstream of the discharge area. For example, within the main channel sites that receive summer input from the Yarragadee, 11 species of fish and 4 species crayfish were captured compared to 4 species of fish and 2 species of crayfish upstream of the discharge zone. Furthermore, the 4 species of fish in the main channel in the upper riverine part of the study area were all halotolerant, whereas most of the additional species present in the sites in the lower section of the river tolerate only low salinities.
A number of species found in the main channel are absent from the tributary sites sampled and vice versa. For example, Freshwater Cobbler, Western Hardyheads, Swan River Gobies and South-western Gobies were only captured in the main channel, while Mud Minnows and Balston’s Pygmy Perch were restricted to tributaries.
The tributaries that receive direct flows from the Yarragadee Aquifer, i.e. Milyeannup Brook and Poison Gully provide important refuges for Balston’s Pygmy Perch and Mud Minnows. Ninety percent of all Balston’s Pygmy Perch were found in Milyeannup Brook and with the exception of one site in the tributaries upstream of the Yarragadee (Leederville Aquifer sites), all Mud Minnows were only found in excavated waterpoints.
Water extraction and the lowering of water tables have the potential to reduce surface water in Milyeannup Brook and Poison Gully and may lead to the elimination of Balston’s Pygmy Perch from the Blackwood River. It may also impact on aestivating fish and freshwater crayfish by drying out the substrates that they burrow into. The main channel section of the Blackwood River that receives flow from the Yarragadee Aquifer supports a number of recreational fisheries, the most important being the Marron fishery, and reduced freshwater input from the Yarragadee Aquifer may comprise these fisheries. Reduced inflow of freshwater could potentially lead to an increase in salinity of this part of the river and may be intolerable to a number of species (see Discussion)
Osteology of the first dorsal fin in two terapontids, Leiopotherapon unicolor (G|nther, 1859) and Amniataba caudavittata (Richardson, 1845), from Western Australia: evidence for hybridisation?
Full text linkOsteological characters, such as number of supraneural bones anterior to first neural spine, number of spines on first dorsal pterygiophore, position of insertion of first proximal dorsal pterygiophore and number of anterior proximal dorsal pterygiophores inserting between successive neural spines, in conjunction with morphological characters, were used to provide evidence of natural hybridisation between two species of the Terapontidae: the freshwater Leiopotherapon unicolor and the marine/estuarine Amniataba caudavittata
Goldfish control in the Vasse River: summary of the 2008 programme
Full text linkThis report summarises the results of the 2008 round of the feral Goldfish control in the lower Vasse River and comparisons made with previous control efforts since 2004
Overview of the feral Goldfish Control Programme in the Vasse River, Western Australia: 2004-2006
Full text linkThe establishment of introduced fishes outside their natural range is often facilitated by a wide tolerance to environmental regimes, maximisation of reproductive potential, high genetic diversity and tendency for good dispersal mechanisms (r-strategists) (Stauffer 1984). An expression of a broad diet (e.g. omnivory) and the ability to tolerate degraded habitats also enables exotic species to exist and flourish in foreign environments. Within Australia, examples of omnivorous species that are highly adaptable to an array of environmental conditions include some of the poeciliids, cichlids and cyprinids; groups that are all traditional aquarium species but are naturally absent from the country (see Morgan et al. 2004). While the ecological impacts of some members of these groups are well understood, there is little information with regard to one of the most widely introduced freshwater fishes of the world, i.e. Goldfish (Carassius auratus). Feral populations of Goldfish have been reported from almost every state of Australia (McKay 1984, Koehn and MacKenzie 2004) and indeed are now found throughout much of the world (e.g. Fuller et al. 1999, Skelton 2001). They are also established in almost every state of the United States and are thought to be the first foreign fish species introduced into that country (e.g. Fuller et al. 1999). Goldfish have been implicated with the introductions of parasites to South Africa and Australia (Fletcher and Whittington 1998, Mouton et al. 2001, Hassan, Morgan and Beatty unpublished data) and with the decline of a number of native fishes in the U.S. (Deacon et al. 1964, Moyle 1976).
Within Western Australia, Goldfish are generally restricted to the south-western corner in the vicinity of major population centres where they appear to be most successful in modified or degraded waters (see Figure 1 and Morgan et al. 2004). The only previous biological study (growth and feeding) of wild Goldfish populations in Australia was conducted by Mitchell (1979) who used scales to age fish from South Australia, while Izci (2001) determined growth rates and age and sex compositions for a wild population of Goldfish in Lake Eğirdir, Turkey. The main aim of this study was to implement an ongoing control programme for Goldfish in the Vasse River and thereby reduce the biomass of the species. Secondary aims were to examine the distributions, habitat associations, age compositions, growth rates and diets of Goldfish in this eutrophic waterbody and to develop an understanding of factors contributing to their success
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
