Virtual predictive testing of biomechanical effects of impacts on the human leg

PAM'94 Fourth international conference on virtual predictive testingof industrial prototypes, PARIS, FRANCE, 05-/10/1994 - 05/10/1994In car/pedestrian accident mathematical simulations, it is desirable to extend existing rigid body human model towards deformable finite element models. Thereby a wider range of front car structure/pedestrian interactions can be covered. Even though some injuries to pedestrian are due to contact with the ground, research concerning the severity of injuries due to the car contact, related to the bumper and the bonnet height and stiffness, and to the speed of the vehicle, are being carried out. In a previous study a finite element model of the pedestrian knee-joint in lateral impact was expanded. This paper presents a modelling of a human leg in lateral impact for use in an explicit finite element code. The articulation between each condyle of the femur and the corresponding tuberosity of the tibia is mainly described. The bones entering into the formation of the knee-joint are the condyles of the femur above, the head of the tibia below. The bones are connected together by ligaments, some of which are placed on the exterior (e. g. ; lateral and medial collateral...) of the joint, while others occupy its interior (e. g. ; anterior and posterior crucial...). This model will be impacted to estimate the severity of leg lesions and to predict the risk of leg injuries in car/pedestrian accidents. The effect of the impactor stiffness, velocity and height will be evaluated. Experimental results from static tests and impact tests, to characterise the mechanical behaviour of each part, like the ligaments or the bones, and the whole kinematics of the knee, serve as a basis for the validation of the model

An overview of MADYMO uses at INRETS

4th meeting International MADYMO users meeting, EINDHOVEN, PAYS-BAS, 06-/09/1993 - 07/09/1993This paper describes the modelling approach using MADYMO 2D at INRETS (The French National Institute for Transport and Safety Research). A mathematical dynamic model of the pedestrian leg in lateral impact was developed (M.MATYJEWSKI) to test car fronts in order to estimate the severity of the knee joint lesions and to predict the risk of leg injuries in car/pedestrian accidents. Results of this model were compared with those obtained with an instrumented mechanical leg used in the bumper impact test. A train passenger behaviour during a crash at low speed was developed (J.BLOCH and F.MINNE) to improve the function of the fusible area at each carriage extremities. Results of this model were compared with those obtained during a real scale crash test. The kinematic of a 3 -year old child in a childseat on a passenger car seat is analysed (R.BIARD and J.L.CHANIAC) during a frontal impact. Experimental results from sled tests serve as a basis for the validation of the model

Blood and alveolar lymphocyte subsets in pulmonary cytomegalovirus infection after lung transplantation

BACKGROUND: Cytomegalovirus (CMV) pneumonitis has been shown to be associated with lymphocytic alveolitis after lung transplantation. In the present study, we investigated a series of bronchoalveolar (BAL) and blood samples, collected in the absence of rejection or acute infectious episodes. in order -1: to evaluate intra-alveolar cell population changes concomitant with CMV replication and -2: to reappraise the value of cell population analysis in the management of patients after lung transplantation. METHODS: We used flow cytometry to investigate modifications of lymphocyte subpopulations related to pulmonary cytomegalovirus infections in blood and BAL samples from a series of 13 lung transplant recipients. After exclusion of samples obtained during pulmonary rejection, bronchiolitis obliterans or acute bacterial infection, 48 blood and BAL samples were retained for analysis: 17 were CMV positive by shell-vial assay and 31 were CMV negative in blood and BAL. RESULTS: Our results demonstrate that pulmonary CMV infection is associated with a significant increase in the total lymphocyte population in BAL samples, but with minor modifications of the various lymphocyte subpopulations and a significantly higher absolute number of B lymphocytes in blood samples. CONCLUSIONS: Cytomegalovirus pulmonary infection is accompanied by only minor changes in BAL lymphocyte subpopulations. The study of BAL lymphocyte subpopulations therefore appears to be of limited clinical value in the diagnosis of pulmonary CMV infection. However, increased blood B-lymphocytes seems to be a clinical feature associated with CMV infection

Future research directions in injury biomechanics and passive safety research

There has been an increasing trend within the safety environment for funding to be directed towards applied research or towards research developing commercially-exploitable systems. Funding mechanisms such as the EU’s 6th Framework Programme and many national programmes focus on research of likely immediate social benefit, reflecting the use of public finances. These programmes will continue to play an important role in funding safety research, but they typically do not have guidelines specifically directed towards fundamental research questions. Additionally, impartial advice is not always available to help programme managers identify research priorities. This review of biomechanics and passive safety research is intended for use by researchers who may be contemplating research in certain areas and wish independent guidance on specific research questions. It is also intended for use by research funding groups and programme managers who would like impartial guidance on basic research to be supported. It covers engineering research directed at improving vehicles and safety systems for all types of road user. It includes the main research and development tools such as dummy development and humanoid modelling and the important area of crash injury data

ELK1 Uses Different DNA Binding Modes to Regulate Functionally Distinct Classes of Target Genes

Eukaryotic transcription factors are grouped into families and, due to their similar DNA binding domains, often have the potential to bind to the same genomic regions. This can lead to redundancy at the level of DNA binding, and mechanisms are required to generate specific functional outcomes that enable distinct gene expression programmes to be controlled by a particular transcription factor. Here we used ChIP–seq to uncover two distinct binding modes for the ETS transcription factor ELK1. In one mode, other ETS transcription factors can bind regulatory regions in a redundant fashion; in the second, ELK1 binds in a unique fashion to another set of genomic targets. Each binding mode is associated with different binding site features and also distinct regulatory outcomes. Furthermore, the type of binding mode also determines the control of functionally distinct subclasses of genes and hence the phenotypic response elicited. This is demonstrated for the unique binding mode where a novel role for ELK1 in controlling cell migration is revealed. We have therefore uncovered an unexpected link between the type of binding mode employed by a transcription factor, the subsequent gene regulatory mechanisms used, and the functional categories of target genes controlled

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements