Sleepless in Syracuse: Plato and the Nocturnal Council

I defend the Seventh Letter, traditionally attributed to Plato, against Michael Frede's argument that it presents a political philosophy inconsistent with that found in the Laws. Frede argues that Plato had given up the idea of the philosopher-king in his Laws, but the 7th Letter seems to be still committed to the project. I argue the Laws, particularly with the introduction of the Nocturnal Council, has Philosopher-Rulers in all but name. I consider the education of the Nocturnal Council and how it functions relative to the other constitutional structures of Magnesia. Frede advances several other arguments that the 7th Letter is spurious, but it at least escapes the most damning charge that it is inconsistent with the Laws philosophically

Managing business performance: the contrasting cases of two multiple retailers 1920 to 1939

Business performance measurement and management (PMM) systems are often viewed as relatively recent phenomena, responding to the failure of historical practices which prioritised financial measures. But despite the considerable focus on these systems over the last 25 years, they have not lived up to their early promise. This paper looks backwards to understand how practitioners managed their performance in the past. It focuses on two British multiple retailers between 1920 and 1939 and highlights not only the formal processes they adopted but also the role of the informal processes which shaped how they achieved their objectives

Microstegium vimineum Spread Rate in Relation to Two Different Leaf Litter Disturbances and an Evaluation of Aboveground Biomass Accumulation and Photosynthetic Efficiency in Response to Four Light Treatments

Microstegium vimineum is a non-native invasive plant species classified as an annual, shade-tolerant C4 grass. There is limited research regarding variables affecting the spread of M. vimineum. Two studies were conducted to investigate the spread of M. vimineum. A field study was undertaken in 2009 to determine how M. vimineum spreads in relation to litter disturbance. In 2010, a greenhouse study was conducted to determine the impact light has on M. vimineum aboveground biomass, height growth, and photosynthetic efficiency. The field study consisted of three treatments, Undisturbed (Control), Stirring, and Removal of leaf litter, employed along the boundary of existing M. vimineum populations in ½-meter by 2-meter plots. Distance of spread from the existing population and percent cover were documented for one growing season. Plants were counted at the end of the study. Neither stirring nor removal of leaf litter had a significant impact on spread rate, percent cover, or the number of plants in a given treatment suggesting pre-growing season leaf litter disturbance does not influence M. vimineum spread, percent cover, or number of plants. The greenhouse study consisted of growing M. vimineum under four light treatments: 100, 70, 45, and 20 percent of full light. Heights were measured weekly while minimum, maximum, and variable fluorescence emission, non-photochemical and photochemical quenching, and maximum quantum yield of Photosystem II photochemistry (QYmax) were measured every 10 days. Aboveground biomass accumulation was calculated at the end of the study. Results indicate that M. viminuem aboveground biomass accumulation is highest in 70 percent to 100 percent light while photosynthetic efficiency is highest between 45 percent and 70 percent light. This research indicates that M. vimineum does not spread appreciably at low light levels (closed canopies) in areas with litter disturbances that do not change the light regime. M. vimineum has greater aboveground biomass and photosynthetic efficiencies at higher levels of light. Thus, forest disturbances that result in more light reaching the ground may influence the spread of M. vimineum by creating a more favorable environment

Sensory Exploitation And Indicator Models May Explain Red Pelvic Spines In The Brook Stickleback, Culaea Inconstans

Background: Sensory bias models explaining the evolution of sexually selected traits predict that trait preferences evolve as an artifact of a pre-existing preference for certain components of the environment such as specifically coloured prey. Indicator models, in contrast, predict that sexually selected traits indicate mate condition. We investigate the potential for sensory exploitation and condition indication models to explain the evolution of what appears to be a recently evolved sexually selected trait. Question: Did red pelvic spine coloration in male Turnbull National Wildlife Refuge (TNWR) brook stickleback (Culaea inconstans) evolve to exploit a pre-existing sensory bias for red prey, thus helping males draw females to the nest? Or, did it evolve as an intersexual signal indicating male condition to females? Methods: We recorded the frequency of red pelvic spine coloration in males versus females and in breeding versus non-breeding males. We measured the condition factor of males with and without red coloration on their pelvic spines. We presented fish with a paired choice between a red versus an orange, yellow, green, blue, or purple bead, and recorded the proportion of bites at each colour. Results: Red coloration was significantly more common in males than in females and in males during the breeding season than outside the breeding season. Males with strongly red pelvic spines have a significantly higher mean condition factor than those with plain spines. TNWR brook stickleback prefer red to other colours in a predation context. Conclusions: Our results suggest that TNWR brook stickleback red pelvic spine coloration is a secondary sexual character that may exploit a pre-existing sensory bias for red prey while also indicating condition to females

Pond conservation: from science to practice

In Europe, ponds are an exceptionally numerous and widely distributed landscape feature forming a major part of the continental freshwater resource and contributing significantly to freshwater biodiversity conservation. This has been reflected by a growing scientific concern over the first few years of the twenty-first century and is evidenced by an increasing number of academic publications on pond related topics, particularly those relating to biodiversity. It is essential, however, that this expanding scientific knowledge is widely disseminated to those involved with pond management and is then rapidly translated into action. Inevitably, the task of transferring science to practice remains a significant challenge. As a first step towards meeting this challenge the European Pond Conservation Network (EPCN), at its biennial meeting in 2008 in Valencia (Spain), made this the main theme of the conference together with two special workshops further encouraging exchanges between scientists, practitioners and policy makers. The papers selected for this special issue of Hydrobiologia (from over 120 communications presented) are all from the conference. They represent a diverse collection of themes from across the continent and North Africa and present new and original insights into topics as wide ranging as: pond biodiversity; human disturbance; landscape ecology; ecological assessment and monitoring; practical management measures; ecological restoration; hydrology and climate change; invasive species and threatened species. In all cases, the papers demonstrate an overriding need for the development of a tight link between scientific knowledge and management. Furthermore, scientific advances have to be beneficial for on the ground management and, vitally, have to be disseminated, communicated and implemented into local, national and international policy. As such, national and international networks (such as the EPCN) have a central role to play and have to develop a robust information and communication strategy which will enable the dissemination of best practice materials and advice across the continent and beyond. The work contained in this volume represents a step in the right direction and will help to ensure that ponds remain a characteristic and highly visible feature of the European landscape in the twenty-first centur