Silicas for control of the poultry red mite Dermanyssus gallinae

Control of the poultry red mite Dermanyssus gallinae is a challenge for organic as well as conventional egg producers. In organic agriculture, control should be attempted by mechanically acting substances (e.g. oils or diatomaceous earth), before acaricides are applied. Diatomaceous earth (DE) without acaricides was at least as effective as DE supplemented with pyrethrum or essential oils and a liquid formulation of silica in vitro. In on farm experiments, DE was effective during a limited period only, whereas the liquid formulation had a very good residual effect over several weeks

Development of prevention and treatment strategies for parasites in poultry

Parasitic infections are likely to be more important in organic and other free-range hens than in birds kept indoors. Several workpackages of QLIF aim at improving prevention and therapy of helminth (Ascaridia galli and Heterakis gallinarum) and arthropod (Dermanyssus gallinae) parasites of laying hens. This paper is a summary of the work undertaken in the first 3 years of QLIF

Ockham on Memory and Double Intentionality

Ockham developed two theories to explain the intentionality of memory: one theory that takes previously perceived things to be the objects of memory, and another that takes one’s own earlier acts of perceiving to be the objects of memory. This paper examines both theories, paying particular attention to the reasons that motivated Ockham to give up the first theory in favor of the second. It argues that the second theory is to be understood as a theory of double intentionality. At the core of this theory is the thesis that one directly remembers one’s own acts, and indirectly also the objects of these acts. The paper analyzes the cognitive mechanism that makes this double intentionality possible and examines the causal account that Ockham gave for explaining the emergence of acts of remembering. It emphasizes that he accepted nothing more than a causal chain of acts and habits, thereby offering an ontologically parsimonious theory of memory.Peer Reviewe

Can We Know Substances? Suárez on a Sceptical Puzzle

It has often been said that the knowability of substances became a problem in the early modern period, when anti-Aristotelians doubted that we could know anything more than the sensory qualities that are present to us. This article argues that the late scholastic Aristotelian Francisco Suárez was already aware of this sceptical problem. On his view, substances are really (and not just modally) distinct from the perceivable qualities, and therefore cannot be known through sense perception. The article first examines the metaphysical theory that motivated him to defend this thesis. It then looks at the epistemological consequences he drew from it. Though he rejected direct knowledge of substances, he nevertheless conceded that knowledge can be obtained through a “discursive process”. The article explores this process, spelling out all the cognitive steps it involves. In particular, it analyses Suárez's explanation of how we produce special cognitive devices (the “intelligible species”) that enable us to represent substances. Finally, it assesses Suárez's solution to the knowability problem by comparing it to Locke's solution. It argues that metaphysical rationalism led him to posit substances: we need to accept them as active causes and bearers of qualities, although we have no direct access to them.Peer Reviewe

Emotions and cognitions

Medieval philosophers clearly recognized that emotions are not simply "raw feelings" but complex mental states that include cognitive components. They analyzed these components both on the sensory and on the intellectual level, paying particular attention to the different types of cognition that are involved. This paper focuses on William Ockham and Adam Wodeham, two fourteenth-century authors who presented a detailed account of "sensory passions" and "volitional passions". It intends to show that these two philosophers provided both a structural and a functional analysis of emotions, i.e., they explained the various elements constituting emotions and delineated the causal relations between these elements. Ockham as well as Wodeham emphasized that "sensory passions" are not only based upon cognitions but include a cognitive component and are therefore intentional. In addition, they pointed out that "volitional passions" are based upon a conceptualization and an evaluation of given objects. This cognitivist approach to emotions enabled them to explain the complex phenomenon of emotional conflict, a phenomenon that has its origin in the co-presence of various emotions that involve conflicting evaluations.Peer Reviewe

Run management for organic layers

Layer runs are often bare and loaded with nutrients and with infectious stages of helminths. Various management strategies are recommended in order to better distribute the hens in the run, thereby preventing local accumulation of droppings and related problems. However, little is known about the impact of those strategies. A series of on farm experiments has been performed in order to test the effects of flock size and of artificial structures on the dispersal of the hens in the run. Further studies evaluated the effects of mowing and run size as well as rotational use of runs on turf quality, nutrient load in the soil and on the infection of the hens with internal parasites. As a summary, introducing structures or applying a rotational management scheme improves run use and facilitates mowing, thus improving turf quality in the run in front of the henhouse. However, the expected reduction of helminth infections and nutrient accumulation has not been observed

Geographies of assisted reproduction : The Spanish egg donation economy as a global/intimate contact zone

This article starts from the idea that a fertility clinic is a "contact zone" where differently positioned subjects meet. Broader power relations become tangible in this specific geography of assisted reproduction. This article examines different scales, such as the fertility clinic itself, the national context of reproductive politics in Spain, and the transnational connections of contemporary clinic consortia. By doing so, we reveal the interrelationships that shape this contact zone from the intimate to the global. This interscalar analysis leads to a critique of a transnational fertility industry that is heavily inflicted with logics of productivity and capital accumulation and in which the lives of egg receivers are valued over the lives of egg donors.Aquest article parteix de la idea que la clínica de fertilitat és una «zona de contacte» on es troben subjectes en diferents posicions i es tornen tangibles relacions de poder més àmplies. L'article examina diferents escales, com la mateixa clínica de fertilitat, el context nacional de la política reproductiva a Espanya i les connexions transnacionals dels consorcis clínics contemporanis. En fer-ho, revelem les interrelacions que donen forma a aquesta zona de contacte des del que és íntim fins al que és global. Aquesta anàlisi interescalar ens porta a la crítica d'una indústria transnacional de la fertilitat que està fortament imbuïda de lògiques de productivitat i acumulació de capital i en què la vida de les receptores d'òvuls es valora més que la de les donants d'òvuls.Este artículo parte de la idea de que la clínica de fertilidad es una «zona de contacto» en la que se encuentran sujetos en diferentes posiciones y se vuelven tangibles relaciones de poder más amplias. El artículo examina diferentes escalas, como la propia clínica de fertilidad, el contexto nacional de la política reproductiva en España y las conexiones transnacionales de los consorcios clínicos contemporáneos. Al hacerlo revelamos las interrelaciones que dan forma a esta zona de contacto desde lo íntimo hasta lo global. Este análisis interescalar nos lleva a la crítica de una industria transnacional de la fertilidad que está fuertemente imbuida de lógicas de productividad y acumulación de capital y en la que la vida de las receptoras de óvulos se valora más que la de las donantes de óvulos.Cet article part de l'idée que la clinique de fertilité est une «zone de contact» dans laquelle se retrouvent des sujets dans des positions différentes et des relations de pouvoir plus larges deviennent tangibles. Cet article examine différentes échelles, telles que celle de la cli-nique de fertilité elle-même, le contexte national de la politique de reproduction en Espagne et les connexions transnationales des consortiums cliniques contemporains. Ce faisant, nous révélons les interrelations qui façonnent cette zone de contact de l'intime au global. Cette analyse interscalaire conduit à une critique d'une industrie transnationale de la fécondité fortement imprégnée de logiques de productivité et d'accumulation de capital et dans laquelle la vie des receveuses d'ovules est plus valorisée que celle des donneuses d'ovules

4D GPS water vapor tomography: new parameterized approaches

Water vapor is a key variable in numerical weather prediction, as it plays an important role in atmospheric processes. Nonetheless, the distribution of water vapor in the atmosphere is observed with a coarse resolution in time and space compared to the resolution of numerical weather models. GPS water vapor tomography is one of the promising methods to improve the resolution of water vapor measurements. This paper presents new parameterized approaches for the determination of water vapor distribution in the troposphere by GPS. We present the methods and give first results validating the approaches. The parameterization of voxels (volumetric pixels) by trilinear and spline functions in ellipsoidal coordinates are introduced in this study. The evolution in time of the refractivity field is modeled by a Kalman filter with a temporal resolution of 30 s, which corresponds to the available GPS-data rate. The algorithms are tested with simulated and with real data from more than 40 permanent GPS receiver stations in Switzerland and adjoining regions covering alpine areas. The investigations show the potential of the new parameterized approaches to yield superior results compared to the non parametric classical one. The accuracy of the tomographic result is quantified by the inter-quartile range (IQR), which is decreased by 10-20% with the new approaches. Further, parameterized voxel solutions have a substantially smaller maximal error than the non parameterized ones. Simulations show a limited ability to resolve vertical structures above the top station of the network with GPS tomograph