Développement et application in situ de nouvelles techniques pour déterminer la tension mécanique dans les haubans des lignes de transmission en utilisant les téléphones intelligents

RÉSUMÉ: Afin de s’assurer de la stabilité des pylônes haubanés des lignes de transmission, il est essentiel de mesurer la tension mécanique dans les haubans. Les méthodes les plus utilisées à cet effet par Hydro-Québec, partenaire du projet présenté dans ce mémoire, sont le tensiomètre PIAB et la méthode du retour d’onde. D’une part, le PIAB nécessite une calibration complexe. D’autre part, la méthode du retour d’onde dépend de l’utilisateur et peut s’avérer peu précise. Ainsi, il existe un besoin pour développer une nouvelle technique complémentaire. La technique développée dans le cadre de ce mémoire est une implémentation de la méthode de vibration avec l’utilisation d’un téléphone intelligent. Elle nécessite trois étapes successives. Tout d’abord, les vibrations du hauban sont enregistrées pendant un temps donné.Ensuite, les signaux d’accélération sont utilisés en entrée d’une méthode d’analyse modale afin de déterminer la fréquence fondamentale du câble.----------ABSTRACT: The stability of guyed transmission towers is mainly ensured by their guy wires. The mechanical tensions in the guy wires have then to be regularly monitored. Currently, most frequently used methods are the PIAB tension meter and the wave-return method. On one hand, the tension meter requires a complex calibration. On the other hand, the wave-return method is user-dependent and can prove to lack accuracy. Therefore, there is a growing need for the development and validation of new techniques. The new tension prediction technique propose din this work is based on the use of smartphones. It finds its origins from the vibration method. Its operation requires three steps. Firstly, cable vibrations are recorded during a given time period. Secondly, a modal analysis method is performed on the acceleration data. The cable fundamental frequency is obtained. Thirdly, a practical formula is implemented. The mechanical tension is given as a function of the fundamental frequency. The three steps are gathered in an Android mobile phone application. In order to fasten the smartphone on the guy wire, a casing is designed. Additionally, a step by step procedure for the mechanical tension estimation is proposed. Finally, in-situ vibration tests are performed on a case study

Toxocariasis Might be an Important Cause of Atopic Myelitis in Korea

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis

Molecular monitoring of plasmodium falciparum drug susceptibility at the time of the introduction of artemisinin-based combination therapy in Yaoundé, Cameroon: Implications for the future

<p>Abstract</p> <p>Background</p> <p>Regular monitoring of the levels of anti-malarial resistance of <it>Plasmodium falciparum </it>is an essential policy to adapt therapy and improve malaria control. This monitoring can be facilitated by using molecular tools, which are easier to implement than the classical determination of the resistance phenotype. In Cameroon, chloroquine (CQ), previously the first-line therapy for uncomplicated malaria was officially withdrawn in 2002 and replaced initially by amodiaquine (AQ) monotherapy. Then, artemisinin-based combination therapy (ACT), notably artesunate-amodiaquine (AS-AQ) or artemether-lumefantrine (AL), was gradually introduced in 2004. This situation raised the question of the evolution of <it>P. falciparum </it>resistance molecular markers in Yaoundé, a highly urbanized Cameroonian city.</p> <p>Methods</p> <p>The genotype of <it>pfcrt </it>72 and 76 and <it>pfmdr1 </it>86 alleles and <it>pfmdr1 </it>copy number were determined using real-time PCR in 447 <it>P. falciparum </it>samples collected between 2005 and 2009.</p> <p>Results</p> <p>This study showed a high prevalence of parasites with mutant <it>pfcrt </it>76 (83%) and <it>pfmdr1 </it>86 (93%) codons. On the contrary, no mutations in the <it>pfcrt </it>72 codon and no samples with duplication of the <it>pfmdr1 </it>gene were observed.</p> <p>Conclusion</p> <p>The high prevalence of mutant <it>pfcrt </it>76T and <it>pfmdr1 </it>86Y alleles might be due to the choice of alternative drugs (AQ and AS-AQ) known to select such genotypes. Mutant <it>pfcrt </it>72 codon was not detected despite the prolonged use of AQ either as monotherapy or combined with artesunate. The absence of <it>pfmdr1 </it>multicopies suggests that AL would still remain efficient. The limited use of mefloquine or the predominance of mutant <it>pfmdr1 </it>86Y codon could explain the lack of <it>pfmdr1 </it>amplification. Indeed, this mutant codon is rarely associated with duplication of <it>pfmdr1 </it>gene. In Cameroon, the changes of therapeutic strategies and the simultaneous use of several formulations of ACT or other anti-malarials that are not officially recommended result in a complex selective pressure, rendering the prediction of the evolution of <it>P. falciparum </it>resistance difficult. This public health problem should lead to increased vigilance and regular monitoring.</p

A Case of Recurrent Toxocariasis Presenting With Urticaria

Human toxocariasis is the most prevalent helminthiasis in Korea and other industrialized countries. The clinical features of toxocariasis are diverse, according to the involved organ. Typically, Toxocara spp. infection is easily treated with 400 mg albendazole twice a day for 5 days. However, we experienced a case of recurrent toxocariasis that was refractory to this standard therapy and presented with urticaria, an uncommon symptom in toxocariasis. A 35-year-old male visited our emergency room because of abdominal pain. He had recently consumed raw cow liver (3 weeks prior to presentation). Laboratory analyses revealed eosinophilia (1,612 cells/µL) and increased total IgE (3,060 IU/mL). Chest X-ray showed multiple lung nodules in both lungs, and computed tomography revealed multiple ground-glass opacities in both lungs and multiple tiny liver abscesses. Liver biopsy revealed an eosinophilic abscess. Enzyme-linked immunosorbent assay findings for Toxocara antigens were positive (optical density, 2.140), leading to a diagnosis of toxocariasis. We initiated a 5-day treatment with albendazole and prednisolone; however, 6 days after completing the treatment, the patient again experienced urticaria and severe itching that could not be controlled by antihistamines or hydrocortisone cream. A second bout of eosinophilia suggested recurring toxocariasis, for which we prescribed a second round of albendazole. Despite an initial improvement in his symptoms, the patient returned after 6 weeks complaining of abdominal pain for 6 hours, which was reminiscent of his first attack; he also exhibited eosinophilia. Accordingly, albendazole was administered once more for an additional 3 weeks, and his symptoms resolved

Toxocariasis: a silent threat with a progressive public health impact

Background: Toxocariasis is a neglected parasitic zoonosis that afflicts millions of the pediatric and adolescent populations worldwide, especially in impoverished communities. This disease is caused by infection with the larvae of Toxocara canis and T. cati, the most ubiquitous intestinal nematode parasite in dogs and cats, respectively. In this article, recent advances in the epidemiology, clinical presentation, diagnosis and pharmacotherapies that have been used in the treatment of toxocariasis are reviewed. Main text: Over the past two decades, we have come far in our understanding of the biology and epidemiology of toxocariasis. However, lack of laboratory infrastructure in some countries, lack of uniform case definitions and limited surveillance infrastructure are some of the challenges that hindered the estimation of global disease burden. Toxocariasis encompasses four clinical forms: visceral, ocular, covert and neural. Incorrect or misdiagnosis of any of these disabling conditions can result in severe health consequences and considerable medical care spending. Fortunately, multiple diagnostic modalities are available, which if effectively used together with the administration of appropriate pharmacologic therapies, can minimize any unnecessary patient morbidity. Conclusions: Although progress has been made in the management of toxocariasis patients, there remains much work to be done. Implementation of new technologies and better understanding of the pathogenesis of toxocariasis can identify new diagnostic biomarkers, which may help in increasing diagnostic accuracy. Also, further clinical research breakthroughs are needed to develop better ways to effectively control and prevent this serious disease