Indoor Positioning with GNSS-Like Local Signal Transmitters

Not all the techniques proposed have, of course, been based on radio techniques, but they are the most important ones for two main reasons: their level of development and maturity on the one hand and their ability to "cross" or to "get around" obstacles such as walls, furniture or people on the other hand. Optical based techniques, like laser based distance measurements or vision based (camera) scene analysis systems present some real advantages in terms of measurement accuracy (a few millimetres for the former) or orientation determination (very useful for any guidance system, available for the latter). Unfortunately, the foreseen use of positioning devices being mainly dedicated to pedestrians in urban environments, optical obstacles are numerous. These latter techniques are then considered as potential hybridisation candidates. Many types of sensors have also been studied for positioning, such as infrared or ultrasound. Once again, although accuracy can reach centimetre values, the environmental constraints are not compatible with the ubiquitous systems being sought. Another category is, of course, inertial systems which could be a valuable alternative to radio systems: time and distance associated position drifts are not yet sufficiently mastered and the given positioning is relative , which means the need for "something else" in order to provide the user with an absolute location. The object of this section is to focus on radio based approaches

Statistics of Long-Range Force Fields in Random Environments: Beyond Holtsmark

Since the times of Holtsmark (1911), statistics of fields in random environments have been widely studied, for example in astrophysics, active matter, and line-shape broadening. The power-law decay of the two-body interaction, of the form $1/|r|^\delta$, and assuming spatial uniformity of the medium particles exerting the forces, imply that the fields are fat-tailed distributed, and in general are described by stable L\'evy distributions. With this widely used framework, the variance of the field diverges, which is non-physical, due to finite size cutoffs. We find a complementary statistical law to the L\'evy-Holtsmark distribution describing the large fields in the problem, which is related to the finite size of the tracer particle. We discover bi-scaling, with a sharp statistical transition of the force moments taking place when the order of the moment is $d/\delta$, where $d$ is the dimension. The high-order moments, including the variance, are described by the framework presented in this paper, which is expected to hold for many systems. The new scaling solution found here is non-normalized similar to infinite invariant densities found in dynamical systems.Comment: 9 pages 2 figure

Primary Malignant Lymphoma of the Uterus: A Case Report and Review of the Literature

Primary malignant lymphomas in the female genital tract are rare. Most cases are non-Hodgkin lymphomas of which diffuse large B-cell lymphomas are most commonly seen. Symptoms are associated with other, more common diseases; therefore, a doctors’ delay can be expected. In this case a woman presented with complaints of urinary obstruction due to a large tumour in the pelvic area. A laparotomy was performed. A very large tumour of the uterus was found with adherence to the pelvic wall and urinary bladder. Diagnostic histological examination showed a diffuse large B-cell lymphoma. Treatment with R-CHOP chemotherapy was started shortly after the operation. The treatment of patients with a primary malignant lymphoma of the uterus should be individualized with the following options: surgery, radiotherapy and/or chemotherapy

Un rêve d’enfant »

Ellroy, Selby Jr., Hopper pour les sources d’inspiration, Bessie Smith, Pasteur, Rachmaninov, le Portugal pour les sujets… Aude Samama circule avec aisance entre univers personnel et travaux de commandes, pliant le monde à une vision tragique qui emprunte des formes volontiers expressionnistes

Drotrecogin alpha: a rational approach to the treatment of submassive pulmonary embolism?

Combining therapeutic doses of low-molecular-weight heparins and increasing doses of recombinant activated protein C - Drotrecogin alpha (activated), or DAA - is of theoretical interest with regard to the control of coagulation activation. The study by Dempfle and colleagues presents new data showing that endogenous activated protein C levels do not increase in nonseptic patients with pulmonary embolism. However, the results of the addition of these two treatments are puzzling, leaving unresolved the questionable clinical relevance of this combination and the possible increase in bleeding risk

Traitement de la maladie thromboembolique veineuse

Purpose: To describe the drugs used to treat venous thromboembolism (VTE) and to review particular aspects of the management (elastic stockings, thrombolysis, thrombectomy, vena cava filter). Source: Our review of the literature is focused on consensus documents and recent large randomized trials. Principal findings: Subcutaneous low molecular weight heparins (LMWH) have been shown to be both safe and effective for the initial treatment of VTE and have largely replaced unfractionated heparin, unless there is a contraindication to LMWH such as severe renal insufficiency. Low molecular weight heparins or unfractionated heparin are usually administered for five to seven days. Treatment is gradually switched from heparin to oral vitamin K antagonists (VKA) which are usually started the same day as heparin. The duration of oral anticoagulation must be tailored to the individual patient according to the presence of reversible or continuing risk factors. In patients with active cancer, long-term treatment of VTE with LMWH has been shown to be more effective than oral anticoagulation and is recommended for the first three to six months of long-term anticoagulant therapy as an alternative approach to VKA. Elastic stockings are recommended because they have been shown to prevent postthrombotic syndrome. Thrombolysis is, usually, not justified for the treatment of deep venous thrombosis, but is used in cases of massive pulmonary embolism with arterial hypotension and/or shock. Vena cava filter placement is mainly indicated in patients with a proximal deep venous thrombosis and an absolute contraindication to anticoagulation. Conclusions: The initial management of patients with acute VTE has largely been simplified due to the use of LMWH. Early conversion to VKA is recommended for the great majority of patients. New agents, such as anti-Xa or oral thrombin inhibitors, are promising alternatives to heparins or VKA. Objectif: Présenter les médicaments utilisés pour traiter la maladie thromboembolique veineuse (MTEV) et revoir des aspects particuliers de la thérapie comme les bas élastiques, la thrombolyse, la thrombectomie et le filtre cave. Source: Revue de documents de consensus et de grandes études récentes. Constatations principales: Les héparines de bas poids moléculaire (HBPM) sont sûres et efficaces comme traitement initial de la MTEV et remplacent largement ľhéparine non fractionnée, à moins ďune contre-indication à ľHBPM comme ľinsuffisance rénale sévère. Les HBPM ou ľhéparine non fractionnée sont habituellement administrées pendant cinq à sept jours. Puis, on passe graduellement de ľhéparine à la prise orale ďantagonistes de la vitamine K (AVK), débutés en général le même jour que ľhéparine. La durée de ľanticoagulation orale doit être adaptée au patient en fonction de facteurs de risque réversible ou continu. Dans les cas de cancer actif, le traitement de la MTEV avec ľHBPM s'est montré plus efficace que ľanticoagulation orale et il est recommandé pour les trois à six premiers mois de traitement. Les bas élastiques sont recommandés pour prévenir le syndrome post-thrombotique. La thrombolyse n'est pas habituellement justifiée pour traiter la thrombose veineuse profonde, mais est utilisée en cas ďembolie pulmonaire massive avec hypotension et/ou choc artériels. La mise en place ďun filtre cave est principalement indiquée chez les patients souffrant de thrombose veineuse profonde proximale chez qui ľanticoagulation est une contre-indication absolue. Conclusion: Le traitement initial des patients atteints de MTEV a été grandement simplifié avec ľusage de ľHBPM. Le passage précoce aux AVK est recommandé pour la grande majorité des patients. De nouveaux médicaments comme les anti-Xa ou les inhibiteurs de la thrombine oraux, sont des équivalents prometteurs des héparines ou des AV

Transfusion massive et coagulopathie-: physiopathologie et implications cliniques

Purpose: To review the pathophysiology of coagulopathy in massively transfused, adult and previously hemostatically competent patients in both elective surgical and trauma settings, and to recommend the most appropriate treatment strategies. Methods: Medline was searched for articles on "massive transfusion,” "transfusion,” "trauma,” "surgery,” "coagulopathy” and "hemostatic defects.” A group of experts reviewed the findings. Principal findings: Coagulopathy will result from hemodilution, hypothermia, the use of fractionated blood products and disseminated intravascular coagulation. The clinical significance of the effects of hydroxyethyl starch solutions on hemostasis remains unclear. Maintaining a normal body temperature is a first-line, effective strategy to improve hemostasis during massive transfusion. Red cells play an important role in coagulation and hematocrits higher than 30% may be required to sustain hemostasis. In elective surgery patients, a decrease in fibrinogen concentration is observed initially while thrombocytopenia is a late occurrence. In trauma patients, tissue trauma, shock, tissue anoxia and hypothermia contribute to the development of disseminated intravascular coagulation and microvascular bleeding. The use of platelets and/or fresh frozen plasma should depend on clinical judgment as well as the results of coagulation testing and should be used mainly to treat a clinical coagulopathy. Conclusions: Coagulopathy associated with massive transfusion remains an important clinical problem. It is an intricate, multifactorial and multicellular event. Treatment strategies include the maintenance of adequate tissue perfusion, the correction of hypothermia and anemia, and the use of hemostatic blood products to correct microvascular bleeding. Objectif: Revoir la physiopathologie de la coagulopathie chez les adultes transfusés massivement et auparavant compétents sur le plan hémostatique, à la fois dans le contexte ďune intervention chirurgicale réglée ou à la suite ďun traumatisme. Recommander les stratégies thérapeutiques les plus appropriées. Méthode: Dans Medline, nous avons cherché les articles traitant de "massive transfusion,” "transfusion,” "trauma,” "surgery,”"coagulopathy” et "hemostatic defects.” Un groupe ďexperts a examiné les résultats. Constatations principales: La coagulopathie résulte de ľhémodilution, ľhypothermie, ľusage de produits sanguins fractionnés et la coagulation intravasculaire disséminée. La portée clinique des effets des solutions ďhydroxyéthyl-amidon sur ľhémostase n'est toujours pas claire. Le maintien ďune température corporelle normale est une stratégie de première intention efficace pour améliorer ľhémostase pendant la transfusion massive. Les globules rouges sont importants dans la coagulation et des hématocrites supérieurs è 30 % pourraient être nécessaires à une hémostase adéquate. Chez les patients en chirurgie réglée, une baisse de la concentration de fibrinogène est observée précocement tandis que la thrombocytopénie est plus tardive. Chez les traumatisés, le trauma tissulaire, le choc, ľanoxie et ľhypothermie tissulaires contribuent au développement ďune coagulation intravasculaire disséminée et du saignement microvasculaire. Ľutilisation de plaquettes et/ou de plasma frais congelé dépendra du jugement du clinicien ainsi que des résultats des tests de coagulation. La transfusion devra surtout viser le traitement ďune coagulopathie clinique (saignement microvasculaire). Conclusion: La coagulopathie associée à la transfusion massive demeure un important problème clinique. C'est un événement complexe, multifactoriel et multicellulaire. Le traitement comprend le maintien ďune perfusion tissulaire adéquate, la correction de ľhypothermie et de ľanémie et ľusage de produits sanguins hémo-statiques pour corriger le saignement microvasculair