Copper is taken up efficiently from albumin and α2-macroglobulin by cultured human cells by more than one mechanism

Ionic copper entering blood plasma binds tightly to albumin and the macroglobulin transcuprein. It then goes primarily to the liver and kidney except in lactation, where a large portion goes directly to the mammary gland. Little is known about how this copper is taken up from these plasma proteins. To examine this, the kinetics of uptake from purified human  albumin and α2-macroglobulin, and the effects of inhibitors, were measured using human hepatic (HepG2) and mammary epithelial (PMC42) cell lines. At physiological concentrations (3–6 µM), both cell types took up copper from these proteins independently and at rates similar to each other and to those for Cu-dihistidine or Cu-nitrilotriacetate (NTA). Uptakes from   α2-macroglobulin indicated a single saturable system in each cell type, but with different kinetics, and 65–80% inhibition by Ag(I) in HepG2 cells but not PMC42 cells. Uptake kinetics for Cu-albumin were more complex and also differed with cell type (as was the case for Cu-histidine and NTA), and there was little or no inhibition by Ag(I). High Fe(II) concentrations (100–500 µM) inhibited copper uptake from albumin by 20–30% in both cell types and that from {alpha}2-macroglobulin by 0–30%, and there was no inhibition of the latter by Mn(II) or Zn(II). We conclude that the proteins mainly responsible for the plasma-exchangeable copper pool deliver the metal to mammalian cells efficiently and by several different mechanisms.α2-Macroglobulin delivers it primarily to copper transporter 1 in hepatic cells but not mammary epithelial cells, and additional as-yet-unidentified copper transporters or systems for uptake from these proteins remain to be identified.

Competition between cluster fragmentation, C–C bond coupling and C–X bond activation in silver hexynyl cluster cations, [(C4H9CCAg)nAg]+. Size does matter!

Silver hexynyl cluster cations, [(C4H9CCAg)nAg]+, exhibit a rich unimolecular chemistry that is dependant on the cluster size, n (1–5), cluster fragmentation (for all n > 1); C–C bond coupling (n = 3 & 4); C–H bond activation with comcomitant silver hydride formation (n = 1 & 4); C–C bond activation (n = 1 & 4).

Extraction of silver(i) from aqueous solutions in the absence and presence of copper(ii) with a methimazole-based ionic liquid

The ionic liquid (IL) 2-butylthiolonium bis(trifluoromethanesulfonyl)amide, [mimSBu][NTf₂], facilitates the efficient extraction of silver(i) from aqueous media via interaction with both the cation and anion components of the IL. Studies with a conventional aqueous-IL two phase system as well as microextraction of silver(i) by a thick IL film adhered to an electrode monitored in situ by cyclic voltammetry, established that [mimSBu][NTf₂] can extract electroactive silver(i) ions from an aqueous solution. The pH of the aqueous phase decreases upon addition of [mimSBu]⁺, which is attributed to partial release of the hydrogen attached to the N(3) nitrogen atom of the imidazolium ring. The presence of silver(i) further increase the acidity of the aqueous phase as a consequence of coordination with the IL cation component. Voltammetric and ¹H and ¹³C NMR techniques have been used to establish the nature of the silver(i) complexes extracted, and show that the form of interaction with the IL differs from that outlined previously for the extraction of copper(ii). Insights on the competition established when silver(i) is extracted in the presence of copper(ii) are provided. Finally, it is noted that metallic silver can be directly electrodeposited at the electrode surface after extraction of silver(i) into [mimSBu][NTf₂] and that back extraction of silver(i) into aqueous media is achieved by addition of an acidic aqueous solution.

Buxton silver gum reserve: using geographic information systems to investigate historic change in site integrity

Eucalyptus crenulata is a rare species known from only two populations. The Buxton Silver Gum Reserve was set aside in 1978 for the conservation of the species, but this objective may be compromised by changes in the integrity of the landscape immediately surrounding the Reserve. A time sequence of aerial photos and Geographic Information Systems technology has been used to identify patterns of landscape change, and aid in determining appropriate management strategies to minimize negative impacts caused by landscape fragmentation and habitat exposure

The relevance of import competition to merger assessment in Australia

The Australian Competition and Consumer Commission has been criticised for failing to take due account of the impact import competition has on domestic firms when assessing whether or not a proposed merger will be likely to substantially lessen competition. This article reviews the approach taken by the ACCC to import competition in its merger assessments. Consideration is given to both the policy adopted by the ACCC and the statistical relevance that has, in fact, been placed on import competition in merger assessment. A conclusion is then drawn as to the appropriateness of the ACCC's current policy and practice.

Some morphometric and biochemical features of ready-to-migrate silver and pre-migratory yellow stages of the shortfin eel of south-eastern Australian waters

The mean total length (L_T), mass and age of ready to migrate female silver shortfin eels Anguilla australis from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83·2 ± 1·2 cm, 1051 ± 51 g, and 17·2 ± 1·79 years, respectively. The eye index (I_E) of the silver shortfin eels was < 5·2 (mean 7·64 ± 0·29) and differed significantly from that of the yellow shortfin eels collected from two other sites. The I_E increased with L_T (mm) and was related by log I_E= 2·656 log L_T6·925. The per cent moisture, protein and ash content of the liver of silver shortfin eels was significantly lower than in yellow shortfin eels, but lipid content was significantly higher in the former (35·5 ± 2·0%). The mean mass μg mg lipid ‾) of saturates (230·4 ± 2·6 v. 181·7 ±2·6), monoenes (367·4 ± 6·3 v. 290·8 ± 8·9) and PUFA (177·3 ± 5·3 v. 159·7 ± 4·6) in muscle was significantly higher, and the great majority of individual fatty acids was found also in higher quantities in silver shortfin eels. In the liver, the PUFA found in the highest quantity was 22:6n-3, except in shortfin eels from Hopkins River estuary, and the amount of 18:2n-6 in the liver of silver shortfin eels was significantly higher than that in yellow shortfin eels but the reverse was true of 20:4n-6. In both muscle and liver tissues the saturate 16:0 and the monoene 18:ln-9 collectively accounted for >50% of all the fatty acids in the lipid.

Competition policy and prevention of abuses in the TRIPS agreement

The monopoly granted through intellectual property rights can lead to abuses ofsuch monopoly. The TRIPS Agreement recognizes such abuses along with the fact that competition policy can play a significant role in dealing with such abuses. The use of competition policy to deal with the abuse of IP monopolies reguires a discussion ofabuse of the dominant position, definition ot market and substitutability of products and whether the
patenting monopoly automatically puts the right holder in the dominant position. The issue of parallel trade and exhaustion of rights also has anti-competitive implications. The introduction of discriminatory pricing along with any ban on parallel trade would lead to absolute market control, market segregation and market exclusion by the monopolistic industries. [JEL Classiffication: K21, K33]

The effect of private school competition on public school performance in Georgia

This article presents estimates of the effect of private school competition on public school performance. Using data on school districts in Georgia, the authors estimate models relating tenth- and third-grade test scores for either reading or mathematics to the level of private school competition. Test scores are not measurably or significantly higher in areas with greater private school competition, a result robust through multiple estimations using three measures of private school competition and a variety of control variables. The authors address the possible endogeneity between test scores and private school competition using instrumental variables estimators, with percentage of the population that is Catholic, county population in 1980, lagged competition, and various other measures as alternative instruments.

Pieces of silver : examples of the economic impact and management of the silver gull (Larus novaehollandiae) in Melbourne, Australia

Like a number of gull species, the silver gull Larus novaehollandiae has expanded its population in response to human food subsidy. The major anthropogenic food source is food waste at rubbish tips. Other sources of human food waste are also exploited. Many problems result from the activities of these birds, including human health and safety, economic impacts, and effects on the conservation of other species. My study examines aspects of the economic impacts of the silver gull on the human community of the Greater Melbourne Area comprising approximately 4065 km2 (1569 square miles). My data collection method involves identifying sites where problems have been experienced and completing questionnaires during face to face interviews with the managers of those sites. Data collected at this early stage of the study demonstrate that there are significant, quantifiable economic impacts associated with the superabundance of the silver gull in this area. Other impacts, such as reduced amenity and potential health hazards are equally real but more difficult to quantify. Costs include damage to structures and products, damage prevention measures, and loss of production. Information about the costs of these problems will be presented to the relevant landfill management authorities to encourage them to consider alternative means of disposing of putrescible waste, rather than by open landfill disposal, because even current best practice management of open landfill sites (rubbish tips) provides ample opportunity for silver gulls and certain other bird species to exploit this food source. Controlling access by the silver gull to food at rubbish tips would be an important first step in managing the population of this species.