Optimal Control Models and Elicitation of Attitudes towards Climate Damages

This paper examines the consequences of various attitudes towards climate damages through a family of stochastic optimal control models (RESPONSE): cost-efficiency for a given temperature ceiling; cost-benefit analysis with a pure preference for current climate regime and full cost-benefit analysis. The choice of a given proxy of climate change risks is actually more than a technical option. It is essentially motivated by the degree of distrust regarding the legitimacy of an assessment of climate damages and the possibility of providing in due time reliable and non controversial estimates. Our results demonstrate that (a) for early decades abatement, the difference between various decision-making frameworks appears to matter less than the difference between stochastic and non stochastic approach given the cascade of uncertainty from emissions to damages; (b) in a stochastic approach, the possibility of non-catastrophic singularities in the damage function is sufficient to significantly increase earlier optimal abatements; (c) a window of opportunity for action exists up to 2040: abatements further delayed may induce significant regret in case of bad news about climate response or singularities in damages.     

A bee in the corridor: centering and wall-following

In an attempt to better understand the mechanism underlying lateral collision avoidance in flying insects, we trained honeybees (Apis mellifera) to fly through a large (95-cm wide) flight tunnel. We found that, depending on the entrance and feeder positions, honeybees would either center along the corridor midline or fly along one wall. Bees kept following one wall even when a major (150-cm long) part of the opposite wall was removed. These findings cannot be accounted for by the “optic flow balance” hypothesis that has been put forward to explain the typical bees’ “centering response” observed in narrower corridors. Both centering and wall-following behaviors are well accounted for, however, by a control scheme called the lateral optic flow regulator, i.e., a feedback system that strives to maintain the unilateral optic flow constant. The power of this control scheme is that it would allow the bee to guide itself visually in a corridor without having to measure its speed or distance from the walls.     

On the communicative significance of whistles in wild killer whales (Orcinus orca)

Killer whales (Orcinus orca) use pulsed calls and whistles in underwater communication. Unlike pulsed calls, whistles have received little study and thus their function is poorly known. In this study, whistle activities of groups of individually known killer whales were compared quantitatively across behavioural categories. Acoustic recordings and simultaneous behavioural observations were made of northern resident killer whales off Vancouver Island in 1996 and 1997. Whistles were produced at greater rates than discrete calls during close-range behavioural activities than during long-range activities. They were the predominant sound-type recorded during socializing. The number of whistles per animal per minute was significantly higher during close-range behavioural activities than during long-range activities. Evidently, whistles play an important role in the close-range acoustic communication in northern resident killer whales.     

Recurrent congenital toxoplasmosis in a woman with lupus erythematosus

We describe the case of a patient with systemic lupus erythematosus, treated by corticosteroids, who presented during two successive pregnancies with serological reactivation of toxoplasmosis associated with fetal lesions. The first infected fetus died in utero with signs of hydrops. The second fetus was treated in utero with a combination of sulfadoxine and pyrimethamine, administered to the mother, and is now well. The increasing number of immunocompromised pregnant patients with immunity to Toxoplasma gondii may lead to a higher risk of reactivation of maternal toxoplasmosis and congenital infection.     

Fish Welfare in Aquaculture: Explicating the Chain of Interactions Between Science and Ethics

Aquaculture is the fastest growing animal-production sector in the world. This leads to the question how we should guarantee fish welfare. Implementing welfare standards presupposes that we know how to weigh, define, and measure welfare. While at first glance these seem empirical questions, they cannot be answered without ethical reflection. Normative assumptions are made when weighing, defining, and measuring welfare. Moreover, the focus on welfare presupposes that welfare is a morally important concept. This in turn presupposes that we can define the capacities of fish, which is an empirical undertaking that informs and is informed by ethical theories about the moral status of animals. In this article we want to illustrate the need for a constant interaction between empirical scientific research and ethics, in which both fields of research make their own contribution. This is not a novel claim. However, the case of fish sheds new light on this claim, because regarding fish there is still much empirical uncertainty and there is a plurality of moral views on all levels. Therefore, we do not only want to show the necessity of this interaction, but also the added value of a cooperation between ethicists and empirical scientists, such as biologists, physiologists, and ethologists. We demonstrate this by considering the different steps in the process of reflection about and implementation of fish welfare.     

You Eat What You Are: Moral Dimensions of Diets Tailored to One's Genes

Thanks to developments in genomics,dietary recommendations adapted to genetic riskprofiles of individual persons are no longerscience fiction. But what are the consequencesof these diets? An examination of possibleimpacts of genetically tailor-made diets raisesmorally relevant concerns that are analogous to(medical-ethical) considerations aboutscreening and testing. These concerns oftengive rise to applying norms for informedconsent and for the weighing of burdens andbenefits. These diets also have a broaderimpact, especially because food patterns arefull of personal, social and cultural meanings.Diets will change one's food patterns and one'sattitude towards food, and this may implychanges in one's identity. We argue that suchan impact does not necessarily raise moralproblems. Moral concerns are, however, relevantif collective values and shared meanings infood practices are at issue. Therefore, thedevelopment of genetically tailor-made dietsdoes not merely require emphasis on weighingpersonal benefits and burdens and on informedconsent. It also asks for attention to andmoral reflection on the collective valuesinvolved in food practices.     

Interfaces in Cross-Linked and Grafted Bacterial Cellulose/Poly(Lactic Acid) Resin Composites

This article presents approaches to maximize the mechanical performance of bacterial cellulose/poly(lactic acid) composites through chemical modification of the interface. This is achieved by both cross-linking the layered bacterial cellulose structure and by grafting maleic anhydride to the matrix material. Unmodified and glyoxalized bacterial cellulose (BC) networks have been embedded in poly(lactic acid) (PLA) resin and then in maleated resin using a compression molding method. The effect of these chemical modifications on the physical properties of these composites is reported. The tensile properties of the composites showed that Young??s moduli can be increased significantly when both BC networks and PLA were chemically modified. Interface consolidation between layers in BC networks has been achieved by glyoxalization. The effect of these modifications on both stress-transfer between the fibers and between the matrix and the fibers was quantified using Raman spectroscopy. Two competitive deformation mechanisms are identified; namely the mobility between BC layers, and between BC and PLA. The coupling strength of these interfaces could play a key role for optimization of these composites?? mechanical properties.