301 research outputs found

    Bargaining over power: when do shifts in power lead to war?

    Get PDF
    Students of international relations have long argued that large and rapid shifts in relative power can lead to war. But then why does the rising state not alleviate the concerns of the declining one by reducing its expected future power, so that a commitment problem never emerges? For example, states often limit their ability to launch preemptive attacks by creating demilitarized zones, or they abandon armament programs to avoid preventive wars. In a model of complete information, I show that shifts in power never lead to war when countries can negotiate over the determinants of their power. If war occurs, then, it must be that negotiations over power are impossible or too costly. I then show how third parties, domestic politics, and problems of fungibility can increase the costs of such negotiations, and hence lead to war, even under complete informatio

    Hyperinsulinism-hyperammonaemia syndrome: novel mutations in the GLUD1 gene and genotype-phenotype correlations

    Get PDF
    Background: Activating mutations in the GLUD1 gene (which encodes for the intra-mitochondrial enzyme glutamate dehydrogenase, GDH) cause the hyperinsulinism–hyperammonaemia (HI/HA) syndrome. Patients present with HA and leucine-sensitive hypoglycaemia. GDH is regulated by another intra-mitochondrial enzyme sirtuin 4 (SIRT4). Sirt4 knockout mice demonstrate activation of GDH with increased amino acid-stimulated insulin secretion. Objectives: To study the genotype–phenotype correlations in patients with GLUD1 mutations. To report the phenotype and functional analysis of a novel mutation (P436L) in the GLUD1 gene associated with the absence of HA. Patients and methods: Twenty patients with HI from 16 families had mutational analysis of the GLUD1 gene in view of HA (n=19) or leucine sensitivity (n=1). Patients negative for a GLUD1 mutation had sequence analysis of the SIRT4 gene. Functional analysis of the novel P436L GLUD1 mutation was performed. Results: Heterozygous missense mutations were detected in 15 patients with HI/HA, 2 of which are novel (N410D and D451V). In addition, a patient with a normal serum ammonia concentration (21 ”mol/l) was heterozygous for a novel missense mutation P436L. Functional analysis of this mutation confirms that it is associated with a loss of GTP inhibition. Seizure disorder was common (43%) in our cohort of patients with a GLUD1 mutation. No mutations in the SIRT4 gene were identified. Conclusion: Patients with HI due to mutations in the GLUD1 gene may have normal serum ammonia concentrations. Hence, GLUD1 mutational analysis may be indicated in patients with leucine sensitivity; even in the absence of HA. A high frequency of epilepsy (43%) was observed in our patients with GLUD1 mutations

    Extraction of running stance phase using tibial acceleration

    Get PDF

    L'optimisation fusion - confusion : une synthÚse privilégiée du droit et du chiffre

    Get PDF
    National audienceIt is not always easy to dissociate, in the settlement problems, tax and accounting, the main thing and the ac cessory. Generally, mergers are in this case, simplified mergers and universal transmissions, too. When professionals want, in this field, to optimize integrated, legal choices - tax - accounting, it is often obliged to treat the problem, without assistanc e. This autonomy look that this subject is at the crossroads of several disciplines and it is necessary to compose, without really opposing them. The field of mergers and confusion is a good synthesis of the link Law - management. The company which wishes to absorb its 100 % subsidiary can choose between simplified fusion and dissolution confusion. But the evolution of the accounting settlements came to reduce the range of the tax choices. Regarding merger - confusion, the link right - tax - management thus must and especially to think itself from now on within a framework widened “law – tax - accounting - management”.Il n'est pas toujours facile de dissocier, dans les problĂšmes juridiques, fiscaux et comptables, le principal de l'accessoire. Les fusions en gĂ©nĂ©ral sont dans ce cas, les fusions simplifiĂ©es et les transmissions universelles en particulier, aussi. Lorsqu'un professi onnel veut, dans ce domaine, optimiser des choix intĂ©grĂ©s, juridiques - fiscaux - comptables, il est souvent obligĂ© de traiter lui - mĂȘme le problĂšme, sans assistance. Cette autonomie montre que ce sujet est au carrefour de plusieurs disciplines avec lesquel les il faut composer, sans vraiment les opposer. Le domaine des opĂ©rations de fusion - confusion est une bonne synthĂšse de la relation droit - gestion. La sociĂ©tĂ© qui souhaite absorber sa filiale Ă  100 % peut choisir entre fusion simplifiĂ©e et dissolution confusion. Ce choix de nature juridique n’entame que potentiellement la marge de man Ɠ uvre fiscale pour les entitĂ©s en prĂ©sence. Mais l’évolution de la rĂšglementation comptable est venue rĂ©duire la portĂ©e des choix fiscaux. En matiĂšre de fusion - confusion, la relation droit – fiscalitĂ© - gestion doit ainsi et surtout se penser dĂ©sormais dans un cadre Ă©largi « droit - fiscalitĂ© - comptabilitĂ© – gestion »

    Vibration Response of Manual Wheelchairs According to Loads, Propulsion Methods, Speeds, and Ground Floor Types

    Get PDF
    Other funding : doctoral allowance from the Sorbonne University of Paris Nord (France)Manual wheelchair (MWC) users are daily exposed to vibration during propulsion. The impact of such exposure on the MWC user’s health has yet to be proven. To date, no agreement has been reached, presumably on the account of the wide variety of experimental parameters that need to be controlled. A possible solution relies on the implementation of a User/MWC model to point out the effect of propelling conditions (MWC loads, propulsion methods, speeds, and ground floor types) on the vibration exposure and eventually on the MWC user’s health. To feed such a model, the evaluation of the MWC vibration response during propulsion is required. Following a necessary MWC experimental modal analysis under laboratory conditions, this study presents the vibration response of an MWC under various propelling conditions. For each investigated condition, the identified set of modal parameters was provided and the effect on the MWC response to vibration at the User/MWC interfaces was highlighted. Results mostly underline that the response to vibration is highly dependent on the propelling conditions. The speed and the ground floor type greatly affect the vibration response: doubling speed and increasing ground surface roughness imply threefold and eightfold vibration levels, respectively. Finally, the main outcome is that an empty MWC or an MWC loaded with a dummy generates vibration outside the range measured for an MWC loaded with a human body, resulting in a lower frequency content and an almost two-fold vibration level increase. The findings of this study will help enhance the understanding of the health risks that wheelchair users encounter as a result of vibrations

    Vibration Transmission during Manual Wheelchair Propulsion: A Systematic Review

    Get PDF
    Manual wheelchair (MWC) propulsion can expose the user to significant vibration. Human body exposure to certain vibrations can be detrimental to health, and a source of discomfort and fatigue. Therefore, identifying vibration exposure and key parameters influencing vibration transmissibility during MWC propulsion is crucial to protect MWC users from vibration risks. For that purpose, a systematic review using PRISMA recommendations was realized to synthesize the current knowledge regarding vibration transmissibility during MWC propulsion. The 35 retrieved articles were classified into three groups: Vibration content, parameters influencing vibration transmission, and vibration transmission modeling. The review highlighted that MWC users experience vibration in the frequency range detrimental/uncomfortable for human vibration transmission during MWC propulsion depends on many parameters and is still scarcely studied and understood. A modeling and simulation approach would be an interesting way to assist physicians in selecting the best settings for a specific user, but many works (modeling, properties identification, etc.) must be done before being effective for clinical and industrial purposes

    Stringing and dynamics effects on forearm muscular activity during harp playing

    Get PDF
    The practice of a musical instrument requires fine dexterity, repetitive, fast, and precise move­ments, as well as important efforts to set the instrument into vibration, while adopting postures often unnatural for the human body. As a result, musicians are often subject to pain and muscu­loskeletal disorders. In the case of plucked string instruments and especially the concert harp, the plucking force is directly related to the strings’ tension. Consequently, the choice of the strings has to be made based on both, the musician feel while playing, and the musculoskeletal consequences. This paper investigates how the string properties and the playing dynamics affect the finger and wrist muscle activity during harp playing. This study first emphasized the note­ worthy recruitment of the flexor and extensor muscles (42% and 29% of MVC, respectively). Findings outlined further that the fingering choice, the adopted playing dynamics and the string’s material govern the muscular activity level and the playing control. Such results are a first step to better understand how the harp ergonomics may affect the player’s integrity and help them decide the most suitable stringing for their practice

    3D propagation of the shock-induced vibrations through the whole lower-limb during running

    Get PDF
    Shock-induced vibrations to the feet have been related to the feel of comfort, the biomechanical control of performance, and the risk of fatigue or injury. Up to recently, the complexity of measuring the human biodynamic response to vibration exposure implied to focus most of the research on the axial acceleration at the tibia. Using wireless three-dimensional accelerometers, this paper investigates the propagation of shock-induced vibrations through the whole lower-limb during running in the temporal and the spectral domains. Results indicated that the vibrations were not consistent across the lower-limb, showing various spatial and spectral distributions of energy. The amount of energy was not constantly decreasing from the distal to the proximal extremity of the runner’s lower-limb, especially regarding the lateral epicondyle of the femur. Vibrations in the transversal plane of the segments were substantial compared to the longitudinal axis regarding the distal extremity of the tibia, and the lateral epicondyle of the femur. Further, the spectral content was wider at the distal than at the proximal end of the lower-limb. Finally, to get a thorough understanding of the risks incurred by the runners, the need to account for shock-induced vibrations up to 50 Hz has been stressed when investigating three-dimensional vibrations. The overall study raises attention on the substantial importance of the transverse components of the acceleration, and their potential relation to shear fatigue and injury during running

    The Rationality of Prejudices

    Get PDF
    We model an -player repeated prisoner's dilemma in which players are given traits (e.g., height, age, wealth) which, we assume, affect their behavior. The relationship between traits and behavior is unknown to other players. We then analyze the performance of “prejudiced” strategies—strategies that draw inferences based on the observation of some or all of these traits, and extrapolate the inferred behavior to other carriers of these traits. Such prejudiced strategies have the advantage of learning rapidly, and hence of being well adapted to rapidly changing conditions that might result, for example, from high migration or birth rates. We find that they perform remarkably well, and even systematically outperform both Tit-For-Tat and ALLD when the population changes rapidly

    Four degree-of-freedom lumped parameter model of the foot-ankle system exposed to vertical vibration from 10 to 60 Hz with varying centre of pressure conditions

    Get PDF
    Modelling the foot-ankle system (FAS) while exposed to foot-transmitted vibration (FTV) is essential for designing inhibition methods to prevent the effects of vibration-induced white-foot. K-means analysis was conducted on a data set containing vibration transmissibility from the floor to 24 anatomical locations on the right foot of 21 participants. The K-means analysis found three locations to be sufficient for summarising the FTV response. A three segment, four degrees-of-freedom lumped parameter model of the FAS was designed to model the transmissibility response at three locations when exposed to vertical vibration from 10 to 60 Hz. Reasonable results were found at the ankle, midfoot, and toes in the natural standing position (mean-squared error (Δ) = 0.471, 0.089, 0.047) and forward centre of pressure (COP) (Δ = 0.539, 0.058, 0.057). However, when the COP is backward, the model does not sufficiently capture the transmissibility response at the ankle (Δ = 1.09, 0.219, 0.039).This work was supported by a Natural Science and Engineering Council of Canada Discovery Grant [RGPIN/ 4252-2015]
    • 

    corecore