State Dependence and Alternative Explanations for Consumer Inertia

For many consumer packaged goods products, researchers have documented a form of state dependence whereby consumers become "loyal" to products they have consumed in the past. That is, consumers behave as though there is a utility premium from continuing to purchase the same product as they have purchased in the past or, equivalently, there is a psychological cost to switching products. However, it has not been established that this form of state dependence can be identified in the presence of consumer heterogeneity of an unknown form. Most importantly, before this inertia can be given a structural interpretation and used in policy experiments such as counterfactual pricing exercises,alternative explanations which might give rise to similar consumer behavior must be ruled out. We develop a flexible model of heterogeneity which can be given a semi-parametric interpretation and rule out alternative explanations for positive state dependence such as autocorrelated choice errors, consumer search, or consumer learning.

The spatiotemporal pattern of earthworm community in the grass savannas of Lamto (Ivory Coast): The spatiotemporal pattern of earthworm community in the grass savannas of Lamto (Ivory Coast)

The impact of earthworms on both soil physical properties and soil organic matter dynamics has been well documented (Lavelle and Spain 2001). There is a wealth of literature dedicated to the biological mechanisms at work or to empirical approaches based on field data. Assessing the functional role of a species or community implies establishing both time and space scales at which it is effectively the primary determinant of the process(es) at hand. In that context, space-time data analyses are powerful tools to process community data collected on numerous occasions but are, however, not widely disseminated in the community of ecologists. Although computer resources are available, one difficulty is that ad hoc field data are not always easily available which hinders thepercolation of the methods

Synthesis of large-area and aligned copper oxide nanowires from copper thin film on silicon substrate

Large-area and aligned copper oxide nanowires have been synthesized by thermal annealing of copper thin films deposited onto silicon substrate. The effects of the film deposition method, annealing temperature, film thickness, annealing gas, and patterning by photolithography are systematically investigated. Long and aligned nanowires can only be formed within a narrow temperature range from 400 to 500°C. Electroplated copper film is favourable for the nanowire growth, compared to that deposited by thermal evaporation. Annealing copper thin film in static air produces large-area, uniform, but not well vertically aligned nanowires along the thin film surface. Annealing copper thin film under a N2/O2 gas flow generates vertically aligned, but not very uniform nanowires on large areas. Patterning copper thin film by photolithography helps to synthesize large-area, uniform, and vertically aligned nanowires along the film surface. The copper thin film is converted into bicrystal CuO nanowires, Cu2O film, and also perhaps some CuO film after the thermal treatment in static air. Only CuO in the form of bicrystal nanowires and thin film is observed after the copper thin film is annealed under a N2/O2 gas flow

Plant row and soil factors influencing the microspatial patterns of plant-parasitic nematodes on sugarcane in Martinique

Le but de cette étude a été de comparer la micro-répartition de différentes espèces de nématodes phytoparasites et la densité racinaire de plants de canne à sucre, en relation avec le rang et certains paramètres édaphiques, sur un ferrisol caractérisé par trois niveaux de remodelage. Les échantillons de sol et de racine ont été prélevés sur une grille à maille régulière disposée entre deux rangs de canne à sucre. Dans la situation profondément remodelée, où les teneurs en carbone, azote et potassium sont les plus faibles, #Pratylenchus zeae présente une structure spatiale liée au rang de canne. #Helicotylenchus erythrinae montre cette répartition particulière dans les trois situations. Au contraire, #Criconemella onoensis ne montre pas de distribution particulière vis-à-vis du rang et de la quantité de racine et ce, quelle que soit la situation. #Hemicriconemoides cocophillus apparaît disposé en lignes parallèles au rang de canne, dans la direction de la pente. Les répartitions spatiales sont représentées graphiquement et analysées à l'aide de semi-variogrammes afin de confirmer et de caractériser les structures observées. L'utilisation de semi-variogrammes croisés montre des interactions antagonistes entre #C. onoensis$ et les autres espèces. Ces interactions sont plus importantes dans la situation profondément remodelée. En fonction de l'intensité du remodelage et des variations consécutives des paramètres du sol, les répartitions et interactions entre nématodes phytoparasites varient quantitativement et qualitativement. (Résumé d'auteur

A Solution for Phase-one Upgrade of the LHC Low-beta Quadrupoles Based on Nb-Ti

We discuss the possibilities of upgrading the LHC triplet quadrupoles by significantly increasing their aperture (and length), using the Nb-Ti cable of the main dipoles. The goal of this first phase in upgrading the triplet is to allow a rapid improvement of the luminosity mostly by removing limitations related to the triplet aperture. Neither the experimental area, including the TAS, nor the basic optics are modified. By the same token, steps are made to allow a moderate increase of the luminosity within the capabilities of the existing detectors. The triplet aperture is sized to decrease the collimator impedance below significance, allow a potential increase of the luminosity by some 50% or up to a factor of 2 with an external ancillary system acting on the geometrical loss factor. Some extra aperture is foreseen to lower the power deposition, to improve field quality and/or to allow a stronger focusing in the event some baseline beam parameters would not be reached. In this way, the proposed phase-one upgrade is versatile and should allow improved performance in a large range of situations

Modélisation de la distribution géographique de deux scolytes, Tomicus destruens et Tomicus piniperda, en Europe et dans la région méditerranéenne

Article publié suite à l'événement : MEDINSECT 3 ; Hammamet-Tunis (Tunisie) - (2012-05-08 - 2012-05-11).Preliminary note – Data and results presented in that paper come from the original article: Horn A., Kerdelhué C., Lieutier F., Rossi J.P., 2012. Predicting the distribution of the two bark beetles Tomicus destruens and Tomicus piniperda in Europe and the Mediterranean region. Agricultural and Forest Entomology, 14, 358-366.Various factors such as climate and resource availability influence the geographical distributions of organisms. Species that are susceptible to small temperature variations are known to experience rapid distribution shifts as a result of current global warming, sometimes leading to new threats to agriculture and forests. Tomicus destruens and Tomicus piniperda (Coleoptera, Curculionidae, Scolytinae) cause economic damage to pines in Europe and around the Mediterranean Basin. However, their respective potential distributions have not yet been studied at a large scale, mostly because these two species have long been misidentified. The present study aimed to investigate the influence of climatic factors on the geographical distributions of both Tomicus species in Europe and around the Mediterranean Sea, and to establish maps of suitable areas. We used occurrence data from 114 published localities where the presence or absence of both species was unambiguously recorded and confirmed by molecular data, and we gathered WorldClim meteorological records to link the occurrence of insects and climatic data and to build potential distribution maps. The two studied Tomicus species presented parapatric distributions and opposite climate requirements. T. destruens occurs in locations with warmer temperatures, whereas T. piniperda occurs under colder, continental climates. Amongst the investigated climatic variables, temperature appeared to be most correlated with both species distributions. We further extended our approach to explore potential geographical distributions under climate change scenarios. This showed that the distribution of both species is expected to exhibit strong alteration in the near future (2080) corresponding to a marked expansion of T. destruens towards northern Europe and a retractation and fragmentation of the distribution of T. piniperda.Résumé - Différents facteurs, tels que le climat ou la disponibilité de certaines ressources, affectent la distribution géographique des organismes. Aujourd’hui, les espèces sensibles à de faibles variations de température connaissent des modifications de leur aire de distribution sous l’effet du changement climatique, avec parfois de nouveaux risques pour l’agriculture et les forêts. Tomicus destruens et Tomicus piniperda (Coleoptera, Curculionidae, Scolytinae) causent des dégâts importants aux pins en Europe et sur le pourtour méditerranéen mais leur aire de distribution potentielle à une large échelle est encore mal connue, en particulier parce que ces deux espèces ont longtemps été confondues. L’étude présentée ici a pour objectif de mieux comprendre l’impact des variables climatiques sur la distribution géographique des deux espèces et d’établir des cartes de distribution potentielle, actuelles et futures. Nous avons utilisé 114 données d’occurrence publiées pour lesquelles la présence et l’absence des deux espèces sont avérées par des diagnostiques moléculaires. Nous avons utilisé les données climatiques disponibles dans la base « WorldClim » afin d’ajuster des modèles linéaires généralisés pour modéliser les relations climat – occurrences de T. destruens et T. piniperda. Les résultats obtenus montrent que les deux espèces ont des distributions parapatriques et des préférences climatiques différentes. T. destruens est présent dans les zones les plus chaudes tandis que T. piniperda occupe les régions les plus froides ayant probablement des saisons marquées. Nous avons utilisé les modèles précédents pour réaliser une projection permettant d’estimer la distribution potentielle de chaque espèce dans le cadre du scénario de changement climatique IPCC 4 du CIAT (modèle CCCM avec un scénario d’émission a2a). Les résultats indiquent que les distributions des deux espèces devraient connaître d’importants changements à court terme (2080). Ainsi, T. destruens remonterait vers le nord de l’Europe tandis que l’aire de distribution de T. piniperda serait à la fois réduite et très fragmentée