1,424 research outputs found
"Grossraum" and "Realm"
new terms for international law as applied to Monroe Doctrine, areas that Germany considered to be part of its "Grossraum" (economic areas under German supremacy
PRE-INDUSTRIAL MELANISM: THE ORIGIN, MAINTENANCE, AND GENETIC BASIS OF AN URBAN MELANIC MORPH OF THE VERMILION FLYCATCHER.
Industrial melanism is a celebrated evolutionary phenomenon because it demonstrates the efficacy of natural selection in response to anthropogenic environmental change. We investigated a potential instance of industrial melanism in a vertebrate, the vermilion flycatcher (Pyrocephalus rubinus). The species is strikingly bright red throughout its broad range, but a sooty brown morph is abundant in the heavily polluted city of Lima, Peru. We found that plumage morph is perfectly predicted by a single nucleotide polymorphism in the MC1R gene. We quantified genotype and allele frequencies in seven neighborhoods of Lima. Within neighborhoods, there were fewer heterozygotes than expected, and surveys of mated pairs were consistent with assortative mating. The melanic allele frequency dropped from ~60% to ~5% across the urban-suburban interface, implicating strong divergent selection on plumage color. Spatial autoregressive models showed that coastal cloudiness predicted melanic allele frequency, while air pollution did not. We conclude that divergent selection and assortative mating act together to maintain the melanic allele at one extreme of a cloudiness gradient, even with no physical barriers to gene flow. The co-occurrence of industrial pollution and the melanic morph of the vermilion flycatcher is not industrial melanism, but a coincidence of human history and natural history
Does the regulation of manure land application work against agglomeration economies? Theory and evidence from the French hog sector
The well-known increase in the geographical concentration of hog production suggests the presence of agglomeration economies related to spatial spillovers and inter-dependencies among industries. In this paper, we examine whether the restrictions on land application of manure may weaken productivity gains arising from the agglomeration process. We develop a model of production showing the ambiguous spatial effect of land availability and the restriction on the manure application rate. Indeed, while the regulation of manure application triggers dispersion when manure is applied to land as a crop nutrient, it also prompts farmer to adopt manure treatment that favors agglomeration of hog production. Estimations of a reduced form of the spatial model with a spatial HAC procedure applied to data for French hog production for 1988 and 2000 confirm the ambiguous effect of land limitations induced by the restrictions on manure application. It does not prevent spatial concentration of hog production, and even boosts the role played by spatial spillovers in the agglomeration process.hog production, land availability, manure application regulation, agglomeration economies, spatial econometrics
Correspondencia entre C. Schmitt y G. Duso
Transcripción y traducción
Se exponen a continuación la reproducción, la transcripción y la traducción de la carta que Carl Schmitt envió desde Plettenberg, con fecha del 4 de agosto de 1981, a Giuseppe Duso. Este último había enviado previamente al jurista alemán una copia del volumen colectivo La politica oltre lo Stato: Carl Schmitt, poco después de su publicación, en febrero de 1981; luego, le había enviado una breve carta el 26 de julio del mismo año, junto con algunos artículos periodísticos que se habían ocupado del congreso paduano, como una prueba más de la centralidad que poseía en Italia la contribución schmittiana en el debate teórico-político. En aquella carta, el entonces editor del volumen le preguntaba en concreto a Schmitt si había podido leer el libro y si estaba dispuesto a autorizar la publicación de una traducción italiana de Römischer Katholizismus und politische Form (considerado como un clásico del pensamiento político) en la editorial Adelphi, de Milán
Orthèses fonctionnelles à cinématique parallèle et sérielle pour la rééducation des membres inférieurs
Robotics applied to rehabilitation requires specific manipulators: Powered Orthoses. They are orthopedic devices equipped with motors and captors that enable locomotor assistance. These powered orthoses must be capable of reproducing physiological articular trajectories and taking over or simulating the segmentary charges of a movement, mainly walking. One needs to obtain rather high dynamic performances with the help of small activators enabling mechanical integration bearable for its user. This doctoral thesis deals with the conception of such POs as well as it proposes original parallel kinematics that are compared with serial kinematics, i.e. ordinary exoskeletons. We have chosen to limit our study to motor re-education of lower limbs associated to neurological disorders: paratetraplegia, hemiplegia, cerebral palsy, etc. This project was initiated by the Fondation Suisse pour les Cyberthèses (Swiss Foundation for Cyberthoses) in 1999, in collaboration with the Laboratoire de Systèmes Robotiques (Laboratory of Robotic Systems) of the Ecole Polytechnique Fédérale de Lausanne (EPFL). It aims at developing systems of motor re-education and walking assistance, associating powered orthosis with trans-cutaneous and closed-loop electrical muscle stimulation: the MotionMaker™ and the WalkTrainer™. Its goal is to create active muscular participation that respects body dynamics of movements and to quicken re-education, whenever possible. In cases of total paralysis, its purpose is to activate lower limbs in order to reduce side-effects and complications resulting from immobilization. The FSC also makes it its ambition to conceive powered orthoses for autonomous walking with functional electric stimulation in its research programme: the WalkMaker™. To begin with, this doctoral thesis defines the biomechanical bases relative to lower limbs and pelvis. Anthropometrical, kinematic and dynamic data of body segments, as well as space-time parameters of walking have been specified. These data have been used in the theoretical models of the conception of the Powered Orthoses, and applied to the numerical simulations carried out in this study. Then we have presented the state of research on orthoses. The number of projects and the diversity of technologies offer a good illustration of the challenge posed when conceiving Powered Orthoses. So far there are no autonomous Powered Orthoses for re-education of ground walking subsequent to neurological trauma. If it is possible to find treadmills on the market, they are however deficient for medical purposes because of the subject's passivity and lack of pelvis mobility. We have then conceived two Powered Orthoses for a stationary training device: firstly, a serial orthosis of the exoskeleton type has been conceived with three articulations: hip, knee and ankle. Its activators consist in connectingrod and crank systems. Secondly, we have devised a device of leg manipulation with a parallel structure (in the shape of the Greek letter lambda λ). We have modelled these two powered orthoses and carried out a numerical simulation of two movements in order to compare their performances: leg press and cycling. The λ parallel powered orthosis gives better results. Before these findings, we built the prototype of the serial powered orthosis for clinical tests for feasibility of closed-loop controlled electric stimulation. The thesis then offers the design of an unprecedented powered orthosis to be integrated into a walker. We have analyzed and modelled a parallel structure with orthogonal connections and another one with λ connections. The comparative results of the numerical simulations of normal speed walking show that the orthogonal powered orthosis is optimal for an autonomous walker. We have built a prototype, and walking tests with healthy subjects prove the feasibility of such a concept. Finally we carried out two studies for a leg-powered orthosis, compatible with a pelvic PO and the walker. An exoskeleton is compared with a parallel structure. For these two systems, the numerical simulations and models give all the kinematic and dynamic features of the activators. Following these results, we chose the parallel PO so as to design an experimental prototype. It is currently being built as we are writing these lines. To complete the procedures, a chapter deals with the integration of the POs into a walker, with the motorization of the mobile frame and with a system of active body relieving. We also present a system of optical measurements of pelvic movements for diagnosis or for biomechanical studies. The last chapter offer guidelines for development in powered orthosis
Chronicles of Oklahoma
Article explores the death customs associated with the Wichita tribe as a source of recorded information to assist archeologists and ethnologists in understanding these cultural traditions and interpret the findings of burial sites. Carl Schmitt provides more specific detail using the accounts of Wichita tribe members and then draws his own conclusions about the practices
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