Demographic models and the management of endangered species: a case study of the critically endangered Seychelles magpie robin

1. Demographic models are assuming an important role in management decisions for endangered species. Elasticity analysis and scope for management analysis are two such applications. Elasticity analysis determines the vital rates that have the greatest impact on population growth. Scope for management analysis examines the effects that feasible management might have on vital rates and population growth. Both methods target management in an attempt to maximize population growth. 2. The Seychelles magpie robin Copsychus sechellarum is a critically endangered island endemic, the population of which underwent significant growth in the early 1990s following the implementation of a recovery programme. We examined how the formal use of elasticity and scope for management analyses might have shaped management in the recovery programme, and assessed their effectiveness by comparison with the actual population growth achieved. 3. The magpie robin population doubled from about 25 birds in 1990 to more than 50 by 1995. A simple two-stage demographic model showed that this growth was driven primarily by a significant increase in the annual survival probability of first-year birds and an increase in the birth rate. Neither the annual survival probability of adults nor the probability of a female breeding at age 1 changed significantly over time. 4. Elasticity analysis showed that the annual survival probability of adults had the greatest impact on population growth. There was some scope to use management to increase survival, but because survival rates were already high (> 0.9) this had a negligible effect on population growth. Scope for management analysis showed that significant population growth could have been achieved by targeting management measures at the birth rate and survival probability of first-year birds, although predicted growth rates were lower than those achieved by the recovery programme when all management measures were in place (i.e. 1992-95). 5. Synthesis and applications. We argue that scope for management analysis can provide a useful basis for management but will inevitably be limited to some extent by a lack of data, as our study shows. This means that identifying perceived ecological problems and designing management to alleviate them must be an important component of endangered species management. The corollary of this is that it will not be possible or wise to consider only management options for which there is a demonstrable ecological benefit. Given these constraints, we see little role for elasticity analysis because, when data are available, a scope for management analysis will always be of greater practical value and, when data are lacking, precautionary management demands that as many perceived ecological problems as possible are tackled.

On the principal eigenvalue of a Robin problem with a large parameter

We study the asymptotic behaviour of the principal eigenvalue of a Robin (or generalised Neumann) problem with a large parameter in the boundary condition for the Laplacian in a piecewise smooth domain. We show that the leading asymptotic term depends only on the singularities of the boundary of the domain, and give either explicit expressions or two-sided estimates for this term in a variety of situations.

“Normality is threatened by the Monster”: Robin Wood, Romero and zombies

A tribute to Robin Wood, focusing on his influence on horror criticism, and more specifically, on his appraisal of George A. Romero as ‘a great and audacious filmmaker’ through detailed consideration of his zombie movies. The article considers the key elements of his extraordinary influence on horror criticism, and a detailed examination of the monster which most directly responds to horror’s potential ambivalence: the zombie. In order to consider the ambivalence in the relationship between normality and the monster – that central and most important component of Wood’s horror criticism – created by Romero’s zombies, analysis focuses on the materiality of the films through close attention to the bodies on-screen.

The pubstro phenomenon : Robin Hoods of the internet

This paper presents a case study of a compromised Web server that was being used to distribute illegal 'warez'. The mechanism by which the server was compromised is discussed as if the way in which it was found. The hacker organisations that engage in these activities are viewed as a Virtual Community and their rules and code of ethics investigated.

The Robin

This original artwork is part of an ongoing exploration of meaning and appearance. The work is a philosophical consideration of how visual truth and appearance are not always coherent, often reflected in everyday seemingly recognisable objects and creatures. The image also highlights the sacred nature of the bird in nature and history.

Transferências federativas e potência dos contratos: avaliação da lei Robin Hood

Buscando melhorar as condições de vida dos municípios mineiros, o governo estadual mineiro instituiu, em 1995, a lei 12.040, conhecida como Lei Robin Hood. Esta permitia que 25% dos recursos de ICMS a serem distribuídos aos municípios mineiros se dessem sobre resultados observáveis em diversas áreas tais como saúde, educação, conservação ecológica, entre outras. Ou seja, instituia, em relação a estas transferências, um contrato de alto poder com os municípios relacionados às políticas públicas implementadas. O estudo destas transferências (relativas à educação e saúde) mostrou um forte impacto positivo na primeira (e inexistente na segunda). Dada a relativa escassez deste tipo de contrato em transferências federativas, este resultado aponta a necessidade de utilização de instrumentos de maior poder nas relações federativas, buscando incrementar as condições de vida locais.

Características acústicas da oclusiva glotal associada à sequência de Pierre Robin: estudo de caso

A fissura de palato, em associação à Sequência de Pierre Robin, pode favorecer o desenvolvimento de produções atípicas (compensatórias), na fala da criança, como é o caso da oclusiva glotal (golpe de glote) comumente observada em substituição aos sons oclusivos (vozeados ou não). No presente estudo, foi realizada a análise dos parâmetros fonético-acústicos da oclusiva glotal produzidas em /k/ e /g/ por uma criança do gênero feminino, com 5 anos, que apresentava fissura de palato reparada, associada à Sequência de Pierre Robin. Para isso, foram selecionadas seis palavras em que a oclusiva velar encontrava-se na posição inicial da palavra e combinada com as vogais /a/, /i/ e /u/ na posição acentuada. Foi ainda realizado julgamento perceptivo-auditivo por três fonoaudiólogos, que apresentou concordância quanto à presença da oclusiva glotal de 100% para ambas as relações (intra e inter-juízes). Na inspeção dos dados via espectrograma foi observada variabilidade dos parâmetros espectrais (burst e transição formântica) e essas variações também puderam ser computadas considerando as vogais separadamente. A análise estatística revelou diferença estatisticamente significante entre as duas consoantes velares (/k/ e /g/) nos parâmetros espectral (burst), temporal (VOT e duração relativa da oclusiva na palavra) e os relativos às características acústicas das vogais adjacentes às oclusivas (período estacionário de F3). Por fim, as características acústicas da oclusiva glotal sugeriram que a criança pode ter utilizado de estratégias para marcar contrastes fônicos na língua, ainda que os mesmos não tenham magnitude suficiente para serem resgatados auditivamente pelo ouvinte.

Casimir effect for the scalar field under Robin boundary conditions: a functional integral approach

In this work we show how to define the action of a scalar field such that the Robin boundary condition is implemented dynamically, i.e. as a consequence of the stationary action principle. We discuss the quantization of that system via functional integration. Using this formalism, we derive an expression for the Casimir energy of a massless scalar field under Robin boundary conditions on a pair of parallel plates, characterized by constants c(1) and c(2). Some special cases are discussed; in particular, we show that for some values of cl and c(2) the Casimir energy as a function of the distance between the plates presents a minimum. We also discuss the renormalization at one-loop order of the two-point Green function in the philambda(4) theory subject to the Robin boundary condition on a plate.