201,831 research outputs found
Risk assessment of Record Brook interbasin water transfer scheme to the aquatic fauna of the Donnelly and Warren Rivers
No full textThis report describes the fishes and freshwater crayfishes of the Donnelly and Warren River catchments and provides a risk assessment to these fauna of the proposed extraction of water from Record Brook (tributary of the Donnelly River) and subsequent transfer to Scabby Gully Dam (Warren River catchment). The proposed location of the structure in Record Brook is at the gauging station ~1 km upstream from the confluence with the Donnelly River. The project aims to divert peak flows in the winter and spring flow period, transferring around 500 ML each year. The size and shape of the interception structure is yet to be determined, but are likely to incorporate a concrete weir < 5m high and a reservoir.
A total of six sites in Record Brook, Donnelly River and Scabby Gully Dam were sampled and these data were collated with additional historical information on the aquatic fauna of both catchments. An overview of fishes and freshwater crayfishes in the Donnelly River is summarised in Morgan & Beatty (2006), the authors recorded a high diversity of native freshwater species [Salamanderfish, Western Minnow, Black-stripe Minnow, Western Mud Minnow, Nightfish, Western Pygmy Perch, Balston’s Pygmy Perch, Freshwater Cobbler, (metamorphosed) ammocoetes of the Pouched Lamprey, Marron, (Restricted) Gilgie, Koonac, Freshwater Shrimp] as well as several estuarine [Western Hardyhead, Blue-spot Goby, South-west Goby] and non-native species [Mosquitofish, Redfin Perch, Rainbow Trout and Brown Trout]. The Donnelly River system is one of only two in south-western Australia that houses all of the endemic fishes of the region. The fauna of Record Brook contrasted that within the main channel sites of the Donnelly River. Within Record Brook, the fauna was dominated by the Pouched Lamprey, Koonac and Rainbow Trout, with the occasional Marron, Western Minnow and Western Pygmy Perch recorded. Within the Donnelly River main channel sites, the captures included Nightfish, Blue-spot Gobies, the Restricted Gilgie, Freshwater Shrimp and introduced Eastern Mosquitofish.The ichthyofauna of the Warren River consists of 14 fish species and is similar to the Donnelly River with the notable absence of Balston’s Pygmy Perch and Salamanderfish. However, in Scabby Gully dam only Marron and Redfin Perch were observed.
The risks of transfer of parasites and disease, feral/native fish or crayfish from Record Brook to Scabby Gully Dam are low. Threats to fish and freshwater crayfish in Record Brook include changes to water quality (altered flow, altered habitat and/or changes in temperature, oxygen, salinity) and requires ongoing monitoring should the project be implemented. The highest threat to fish and freshwater fish would be the barrier to fish movement by construction of the proposed dam. The construction of a fishway at the proposed dam would reduce some of the negative impacts to fish migration but would also require ongoing monitoring. No specially protected fish and/or crayfish species have been recorded in Record Brook. However, Record Brook acts as an important nursery area for the Pouched Lamprey and this species is listed as a Priority Species (Priority 1) by the Department of Environment and Conservation. The contents of this report are intended to inform of future management options and do not constitute, or replace any assessment or approval processes that may be required in accordance with the Environmental Protection Act 1986 and/or Environmental Protection and Biodiversity Conservation Act 1999
Freshwater fish and crayfish communities of the tributaries of the Margaret River
No full textTributaries and headwaters of major rivers are known to be important spawning and nursery habitats of freshwater endemic fishes in south-western Australia (see for example the Collie River in Pen & Potter 1990, and the Blackwood River in Beatty et al. 2006, 2008). Fishes of the Margaret River have previously been examined by Morgan et al. (1998) and Morgan & Beatty (2003) with the monitoring of the functioning of the two fishways on the river documented in Morgan & Beatty (2004, 2007) and Beatty & Morgan (2008). The river is known to be of conservation importance due to it housing five of the eight endemic freshwater fishes of the south-west region, as well as housing the majority (five of the six species) of the Cherax species of freshwater crayfishes found in the south-west; including the Margaret River endemic Critically Endangered Hairy Marron.
Despite this known value and considerable volume of research on the fishes in the main channel of the Margaret River, little is known on the fishes and freshwater crayfishes of the river 19s major tributaries. The aim of this study is to document the freshwater fish distribution in the major tributaries of the Margaret River (i.e. Bramley, Darch, and Yalgardup Brooks) during or close to the breeding period for the majority of the species and to provide a broad assessment and comparison of population demographics of the different species in the different tributaries. This information is required for the formulation of River Action Plans for these systems by the Cape to Cape Catchments Group
Psychological approaches to assisting individuals diagnosed with cancer
No full textLisa Beatty and Melissa Oxla
Being Proportional about Proportionality. Book review of: The Ultimate Rule of Law. By David M. Beatty
No full textBook review: The Ultimate Rule of Law. By David M. Beatty. New York: Oxford University Press. 2004. Pp. 193 + xvii. Reviewed by: Vicki C. JacksonJackson, Vicki C.. (2004). Being Proportional about Proportionality. Book review of: The Ultimate Rule of Law. By David M. Beatty. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/169729
Über Beatty-Mengen und einige Verallgemeinerungen dieser
No full textBeatty sets (also called Beatty sequences) have appeared as early as 1772 in the astronomical studies of Johann III Bernoulli as a tool for easing manual calculations and - as Elwin Bruno Christoffel pointed out in 1888 - lend themselves to exposing intricate properties of the real irrationals. Since then, numerous researchers have explored a multitude of arithmetic properties of Beatty sets; the interrelation between Beatty sets and modular inversion, as well as Beatty sets and the set of rational primes, being the central topic of this book. The inquiry into the relation to rational primes is complemented by considering a natural generalisation to imaginary quadratic number fields.Zu gegebener Beatty-Menge mit irrationalem und , sowie gegebener Primzahl und hierzu teilerfremdem untersuchen wir das Problem der Auffindung von Punkten auf der modularen Hyperbel
mit so klein wie möglich, d.h. wir für gewisse beweisen nichttriviale Abschätzungen für
Der Beweis fußt auf neuen Abschätzungen für unvollständige Kloosterman-Summen entlang , welche durch das Speisen einer Methode von Banks und Shparlinski mit neuen Abschätzungen für die periodische Autokorrelation der endlichen Folge
erhalten werden; (Hierbei bezeichnet die eindeutige natürliche Zahl mit und wir schreiben .) Für letzteres adaptieren wir Ideen von Kloosterman.
Des weiteren untersuchen wir Mengen der Form . Wir zeigen, dass diese stets in einer gewöhnlichen Beatty-Menge enthalten sind und geben zulässige Werte für und an. Das Komplement erweist sich als endliche Menge und wir bestimmen obere Schranken für das Supremum von .
Die Beweise gründen sich auf einfache Verteilungseigenschaften der Folge der Nachkommastellen , , sofern irrational ist, und berufen sich anderenfalls auf die Endlichkeit der Frobenius-Zahl einer geeignet gewählten Instanz des Frobeniusschen Münzproblems.
Abschließend verallgemeinern wir die Definition von Beatty-Mengen auf imaginär-quadratische Zahlkörper in einer natürlichen Weise. Hat der fragliche Zahlkörper Klassenzahl , so können wir zeigen, dass diese Beatty-artigen Mengen unendlich viele Primelemente enthalten, sofern der zugehörige Parameter nicht im betrachteten Zahlkörper enthalten ist. Für den speziellen Zahlkörper erhalten wir unter Benutzung des Hurwitzschen Kettenbruch-Algorithmus eine Zahlkörper-Variante eines früheren Resultats von Steuding und dem Autor, welches ein Beatty-Analogon des klassischen Linnikschen Satzes über die kleinste Primzahl in einer arithmetischen Progression darstellt.
Die erwähnten Resultate werden durch Zahlkörper-Varianten von klassischen Ergebnissen über die Verteilung von , , , erhalten; Diese wurden kürzlich von Baier mittels der Harmanschen Siebmethode für bewiesen. Wir übertragen die zugehörigen Überlegungen auf Zahlkörper mit Klassenzahl .For Beatty sets with irrational and , and prime and coprime to , we investigate the problem of detecting points on the modular hyperbola
with as small as possible, i.e., we obtain non-trivial estimates for
for certain .
The proof rests on new estimates for incomplete Kloosterman sums along which are in turn obtained on supplying a method due to Banks and Shparlinski with a new estimate for the periodic autocorrelation of the finite sequence
( denoting the unique integer with and , the latter being obtained from adapting an argument due to Kloosterman.
Furthermore, we investigate sets of the shape . We show that they are always contained in some ordinary Beatty set where we give admissible choices for and . Their respective complement in this ordinary Beatty set is shown to be finite and bounds for the supremum of are provided. The proofs are based on basic distribution properties of the sequence of fractional parts , , when is irrational, and appeal to the finiteness of the Frobenius number associated with a suitably chosen instance of the Frobenius coin problem otherwise.
Lastly, we generalise the definition of Beatty sets to imaginary quadratic number fields in a natural fashion. Assuming the number field in question to have class number , we are able to show that these Beatty-type sets contain infinitely many prime elements provided that the parameter corresponding to from above is not contained in the number field. When the number field is , then, using the Hurwitz continued fraction expansion, we obtain a number field analogue of a previous result of Steuding and the author, who gave a Beatty set analogue of Linnik's famous theorem on the least prime number in an arithmetic progression. These results are obtained from number field analogues of classical results about the distribution of , , , which were worked out recently by Baier for using Harman's sieve method. We generalise these arguments to imaginary quadratic number fields with class number
Ascending the Avon: fishes of the Northam Pool, and the Swan-Avon catchment
No full textThe fish fauna in the vicinity of the Northam Pool Weir was sampled seasonally between winter 2008 and autumn 2009. The results indicate that the fish community was characterised by species that are halotolerant including two estuarine species, the Western Hardyhead and Swan River Goby that are likely to have undergone large upstream expansions in the Swan‐Avon catchment due to secondary salinisation. However, two freshwater endemic species, the Western Minnow and Nightfish were also recorded in the vicinity of the weir. These, and other freshwater endemic species, have undergone large range reductions in this catchment as a result of salinisation. The study found evidence that the weir may be impeding the upstream movements of native fishes as found elsewhere in south‐western Australia and that construction of a well‐designed fishway would enhance population connectivity and increase their sustainability. It is recommended that additional sampling occurs during the major spawning periods of the freshwater species immediately below the weir to determine precisely when a future fishway would need to operate to allow maximum usage by resident native species. It is also recommended that fresh refuge habitats for freshwater fishes be identified to allow effective management measures to be implemented in those systems to halt their decline and reduce the risk of complete loss of these species from the Swan‐Avon catchment
On m-covering families of Beatty sequences with irrational moduli
No full textWe generalise Uspensky's theorem characterising eventual exact (e.e.) covers of the positive integers by homogeneous
Beatty sequences, to e.e. m-covers, for any m \in \N, by homogeneous sequences with irrational moduli. We also consider inhomogeneous sequences, again with irrational moduli, and obtain a purely arithmetical characterisation of e.e. m-covers. This generalises a result of Graham for
m = 1, but when m > 1 the arithmetical description is more complicated. Finally we speculate on how one might make sense of the notion of an exact m-cover when m is not an integer, and present a "fractional version" of Beatty's theorem
Margaret River Fishway
No full textIn order to enhance the migrations of fish species in the Margaret River, the Margaret River Regional Environment Centre, in conjunction with the Department of Environment, constructed a rock ramp fishway at the Margaret River Weir (Apex Weir) between March and April 2003. Morgan and Beatty (2003) surveyed the fish fauna of the river during March 2003, capturing 9206 fish from five native species, one feral species and the pouched lamprey (Geotria australis) (see Plate 1). All of the native fishes of the river are endemic to south-western Australia while the feral species is the mosquitofish (Gambusia holbrooki). The only other records of fish from the river are those recorded by Morgan et al. (1998) and there are also a few records in the Western Australian Museum.
Large numbers of native fishes were known to be impeded by the town weir on their upstream migration during winter and spring. These native fishes included the western minnow (Galaxias occidentalis), western pygmy perch (Edelia vittata) and nightfish (Bostockia porosa). Furthermore, adult lampreys were often observed negotiating the weirs on Margaret River with the occasional dead animal also observed. The reservoir above the Margaret River Weir had the highest abundance of the feral mosquitofish with this section of the river also containing western minnows, nightfish and western pygmy perch, and beds for larval lampreys (ammocoetes) (Morgan and Beatty 2003). It was thus deemed appropriate that the construction of a fishway on the Margaret River would be beneficial to fish and lamprey migrations in the Margaret River
Note sur un lot de papyrus acquis par M. Chester Beatty
No full textPuech Aimé. Note sur un lot de papyrus acquis par M. Chester Beatty. In: Comptes rendus des séances de l'Académie des Inscriptions et Belles-Lettres, 75ᵉ année, N. 4, 1931. pp. 405-408
Cancellation of Cusp Forms Coefficients over Beatty Sequences on GL(<i>m</i>)
No full textAbstractLet A(n1, n2, … , nm–1) be the normalized Fourier coefficients of a Maass cusp form on GL(m). In this paper, we study the cancellation of A(n1, n2, … , nm–1) over Beatty sequences.</jats:p
- …
