No abstract

White spot disease, which is caused by infections of Ichthyophthirius multifiliis, has a severe impact on productivity in freshwater aquaculture. These infections were previously treated effectively with malachite green, a compound that is now banned on fish farms due to its carcinogenicity. However, aquaculturists need alternative substances to control the disease. Therefore, comparative laboratory tests (in vitro exposure) were performed to elucidate the effects on the infective theront stage and the tomocyst stage of (1) sodium percarbonate, a compound that releases hydrogen peroxide when dissolved in water and (2) extract of garlic Allium sativum. The efficacy of these compounds was compared with that of malachite green. It was demonstrated that at 12ЊC sodium percarbonate (12.5 mg/L) and garlic extract (62.5 mg/L) killed theronts within 3 and 15 h, respectively. Thus, compared with malachite green (0.1 mg/L), higher concentrations of both sodium percarbonate and garlic extract are needed. The effects of the alternative compounds on the tomocyst stage were less pronounced. As expected, malachite green (0.15 mg/L) killed the tomocysts and prevented the development of tomites. In contrast, sodium percarbonate (12.5 mg/L) did not kill the tomocysts. Garlic extract had no effect in low amounts (30 mg/L), but at high concentrations (117 and 570 mg/L) it killed the tomocysts within 24 h. It is concluded that these alternative substances are less effective than malachite green but may represent a way to reduce infections at fish farms with minimal environmental effects. It is emphasized that tolerance tests with various infected and noninfected fish species should be conducted in order to determine safety levels. Further, as the legality of these substances varies across countries, local regulatory authorities should be consulted before using these substances.

Outsourcing the provision of traditionally publicly provided services has become commonplace in most industrialized nations. Despite its prevalence, there still is no consensus in the academic literature on the magnitude (and determinants) of expected cost savings to the government, nor the sources of those savings. This article considers the arguments for (and against) outsourcing and then examines the empirical evidence pertaining to whether any observed savings occur and whether they persist over time. In addition, we examine the existing evidence for the 'redistribution hypothesis' and the 'quality-shading hypothesis', which critics have used to argue that outsourcing lowers government expenditure by lowering wages and conditions and/or lower quality services. Finally, we consider the impact of contract design on outsourcing outcomes. While the power of incentives is a strong theme in economics, recent work has suggested that high-powered incentives may be suboptimal for many public sector services, because they may crowd out intrinsic motivation, particularly in instances where agents are highly motivated. We discuss the implications of this insight for the efficiency of public sector outsourcing.

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Innovation markets are often characterised by market failure because inventions typically incur high fixed costs relative to marginal costs and their intellectual capital is non‐excludable. Intellectual property (IP) rights may attenuate this problem by providing legal recourse for firms to stop imitation by rivals. As IP rights are costly to acquire and enforce, it is often argued that SMEs are disadvantaged in their ability to utilise IP rights. This paper examines the intensity of IP usage by firm size and finds that SMEs actually have higher rates of patent, trade mark and design usage once industry effects are controlled for.