Influence of muscle preactivation of the lower limb on impact dynamics in case of frontal collision

Accidentology or shock biomechanics are research domains mainly devoted to the development of safety conditions for the users of various transport modes in case of an accident. The objective of this study was to improve the knowledge of the biomechanical behaviour of the lower limb facing sudden dynamic loading during a frontal collision. We aimed at establishing the relationship between the level of muscular activity prior to impact, called 'preactivation', of the lower limb extensors and the mechanical characteristics of impact. Relationships were described between the level of preactivation, the impact peak force values, the minimum force after unloading and the associated loading and unloading rates. The existence of reflex mechanisms that were affected by the level of voluntary muscular preactivation for the lower limb muscles was demonstrated. In conclusion, the existence of specific mechanism acting mainly at the knee level may result from the level of preactivation. Muscle behavior has to be included in numerical models of the human driver to better evaluate the overall stiffness of the body before and at impact

THE ADAPTIVE SSC: FROM FATIGUE RUNS ON EARTH TO THE REBOUNDS ON MARS

In natural forms of ground locomotion such as running and jumping, the functional phases include the stretching of the preactivated muscles followed by their shortening. This is called stretch-shortening cycle (SSC). SSC is a natural but complex activity that combines the available structuro-functional resources: the contractile and elastic structures with the central and reflex activation patterns. SSC may thus be used as a model to reveal the neural adjustments and the associated muscle-tendon responses to internal and external constraints. This presentation will focus on the neuro-mechanical adjustments to the acute and delayed SSC fatigue effects and to partial unweighting on lower body positive pressure treadmill. Both testing conditions emphasize the adaptive quality of the SSC, and demonstrate Time-, Task- and SSC phase-dependent neuro-mechanical adjustments

Análisis del comportamiento sísmico de una estructura mixta compuesta de adobe y quincha ubicado en el distrito de Lurín, departamento de Lima

El Perú es uno de los países con mayor potencial sísmico debido a su formación que parte del llamado Anillo de Fuego del Pacífico, zona en la que la Tierra libera más del 85% de la energía acumulada en su interior debido a los procesos de convección del manto. Así mismo el Perú ha albergado culturas que emplearon la tierra como material tradicional de construcción; pese a que, el país está ubicado en una de las zonas más sísmicas de Sudamérica. El objetivo de esta tesis fue analizar el comportamiento sísmico de una estructura mixta compuesta de adobe y quincha ubicada en el distrito de Lurín, Departamento de Lima. Para idealizar una estructura que se ajuste a la realidad, se procedió al pre dimensionamiento estructural de un módulo de dos niveles compuesto por adobe y quincha, de acuerdo a las Normas Técnicas E. 030 y E. 080. Así mismo se modeló la estructura en el Software ETABS v. 19 y se realizó el análisis dinámico estático. A partir de la evaluación realizada al sistema dual adobe – quincha, se demostró que esta metodología de construcción es efectivamente resistente ante un comportamiento sísmico. La resistencia sísmica que aporta el adobe cumplió con brindar la resistencia estructural correspondiente al primer nivel y la flexibilidad de la quincha influyó en la rigidez de la estructura en el segundo nivel. Así mismo, se demostró que la estructura mixta tiene similar resistencia a la de una vivienda con estructura compuesta de ladrillos y concreto ante un comportamiento sísmico. Finalmente, según la evaluación de costos realizada resultó que una vivienda construida con materiales derivados de la tierra es 3 a 4 veces menor que una estructura compuesta de material noble

Evolution comparée de la consommation de médicaments dans les 5 pays européens entre 2000 et 2004 : analyse de 7 classes pharmaco-thérapeutiques

The drug consumption level in France is often considered as being one of the most important in Europe. This study aims at confirming this assertion over the period 2000-2004 by comparing drug consumption in Germany, Spain, France, Italy and the United-Kingdom. The results show that in 2004 drug consumption in France was no more the biggest for all the seven studied classes. Moreover, the consumption levels of the five countries have converged between 2000 and 2004, as well as the consumption structures.Defined Daily Dose (DDD); Drug Consumption; European Comparative Analysis

Between Metropole and Province: circulating botany in British museums, 1870–1940

Exchange of duplicate specimens was an important element of the relationship between metropolitan and regional museums in the period 1870–1940. Evidence of transfers of botanical museum objects such as economic botany specimens is explored for the Royal Botanic Gardens, Kew, and six museums outside the capital: Cambridge University Botanical Museum, National Museum Wales, Glasgow Museums, Liverpool World Museum, Manchester Museum and Warrington Museum. Botany became an important element in these museums soon after their foundation, sometimes relying heavily on Kew material as in the case of Glasgow and Warrington, and usually with a strong element of economic botany (except in the case of Cambridge). Patterns of exchange depended on personal connections and rarely took the form of symmetrical relationships. Botanical displays declined in importance at various points between the 1920s and 1960s, and today only Warrington Museum has a botanical gallery open to the public. However, botanical objects are finding new roles in displays on subjects such as local history, history of collections, natural history and migration

Phantom-Mobility-Based Prosthesis Control in Transhumeral Amputees Without Surgical Reinnervation: A Preliminary Study

Transhumeral amputees face substantial difficulties in efficiently controlling their prosthetic limb, leading to a high rate of rejection of these devices. Actual myoelectric control approaches make their use slow, sequential and unnatural, especially for these patients with a high level of amputation who need a prosthesis with numerous active degrees of freedom (powered elbow, wrist, and hand). While surgical muscle-reinnervation is becoming a generic solution for amputees to increase their control capabilities over a prosthesis, research is still being conducted on the possibility of using the surface myoelectric patterns specifically associated to voluntary Phantom Limb Mobilization (PLM), appearing naturally in most upper-limb amputees without requiring specific surgery. The objective of this study was to evaluate the possibility for transhumeral amputees to use a PLM-based control approach to perform more realistic functional grasping tasks. Two transhumeral amputated participants were asked to repetitively grasp one out of three different objects with an unworn eight-active-DoF prosthetic arm and release it in a dedicated drawer. The prosthesis control was based on phantom limb mobilization and myoelectric pattern recognition techniques, using only two repetitions of each PLM to train the classification architecture. The results show that the task could be successfully achieved with rather optimal strategies and joint trajectories, even if the completion time was increased in comparison with the performances obtained by a control group using a simple GUI control, and the control strategies required numerous corrections. While numerous limitations related to robustness of pattern recognition techniques and to the perturbations generated by actual wearing of the prosthesis remain to be solved, these preliminary results encourage further exploration and deeper understanding of the phenomenon of natural residual myoelectric activity related to PLM, since it could possibly be a viable option in some transhumeral amputees to extend their control abilities of functional upper limb prosthetics with multiple active joints without undergoing muscular reinnervation surgery

Progesterone after previous preterm birth for prevention of neonatal respiratory distress syndrome (PROGRESS): a randomised controlled trial

Background: Neonatal respiratory distress syndrome, as a consequence of preterm birth, is a major cause of early mortality and morbidity during infancy and childhood. Survivors of preterm birth continue to remain at considerable risk of both chronic lung disease and long-term neurological handicap. Progesterone is involved in the maintenance of uterine quiescence through modulation of the calcium-calmodulin-myosin-light-chain-kinase system in smooth muscle cells. The withdrawal of progesterone, either actual or functional is thought to be an antecedent to the onset of labour. While there have been recent reports of progesterone supplementation for women at risk of preterm birth which show promise in this intervention, there is currently insufficient data on clinically important outcomes for both women and infants to enable informed clinical decision-making. The aims of this randomised, double blind, placebo controlled trial are to assess whether the use of vaginal progesterone pessaries in women with a history of previous spontaneous preterm birth will reduce the risk and severity of respiratory distress syndrome, so improving their infant's health, without increasing maternal risks. Methods Design: Multicentred randomised, double blind, placebo-controlled trial. Inclusion Criteria: pregnant women with a live fetus, and a history of prior preterm birth at less than 37 weeks gestation and greater than 20 weeks gestation in the immediately preceding pregnancy, where onset of labour occurred spontaneously, or in association with cervical incompetence, or following preterm prelabour ruptured membranes. Trial Entry & Randomisation: After obtaining written informed consent, eligible women will be randomised between 18 and 23+6 weeks gestation using a central telephone randomisation service. The randomisation schedule prepared by non clinical research staff will use balanced variable blocks, with stratification according to plurality of the pregnancy and centre where planned to give birth. Eligible women will be randomised to either vaginal progesterone or vaginal placebo. Study Medication & Treatment Schedules: Treatment packs will appear identical. Woman, caregivers and research staff will be blinded to treatment allocation. Primary Study Outcome: Neonatal Respiratory Distress Syndrome (defined by incidence and severity). Sample Size: of 984 women to show a 40% reduction in respiratory distress syndrome from 15% to 9% (p = 0.05, 80% power). Discussion: This is a protocol for a randomised trial.Jodie M. Dodd, Caroline A. Crowther, Andrew J. McPhee, Vicki Flenady, and Jeffrey S. Robinso