Normalised natural gradient algorithm for the separation of cyclostationary sources

A normalised natural gradient algorithm (NGA) for the separation of cyclostationary source signals is proposed in this paper. It improves the convergence properties of the cyclostationary natural gradient algorithm (CSNGA) by employing a gradient adaptive learning rate whose value changes in response to some change in the filter parameters. Experimental results demonstrate the improved behaviour of the approach

A novel adaptive algorithm for the blind separation of periodic sources

An adaptive algorithm for the blind separation of periodic sources is proposed in this paper. The method uses only the second order statistics of the data, and exploits the periodic nature of the source signals. Simulation results show that the proposed approach has the ability to restore statistical independence, and its performance is comparable to that of a well established, higher order, blind source separation method

Fetal electrocardiogram extraction by sequential source separation in the wavelet domain

This work addresses the problem of fetal electrocardiogram extraction using blind source separation (BSS) in the wavelet domain. A new approach is proposed, which is particularly advantageous when the mixing environment is noisy and time-varying, and that is shown, analytically and in simulation, to improve the convergence rate of the natural gradient algorithm. The distribution of the wavelet coefficients of the source signals is then modeled by a generalized Gaussian probability density, whereby in the time-scale domain the problem of selecting appropriate nonlinearities when separating mixtures of both sub- and super-Gaussian signals is mitigated, as shown by experimental results

Gangrenous Appendicitis in an Elderly Male

Background: Appendicitis is one of the most common causes of acute abdomen with 250,000 cases reported annually in the U.S. Clinical manifestations include right lower quadrant abdominal pain, nausea, vomiting, and low grade fever. However, in the elderly population they may present with atypical or non-specific symptoms of appendicitis. Case Presentation: An 82-year-old Hispanic gentleman presents to the emergency department with chief complaint of epigastric pain, dizziness and vomiting after eating breakfast in the morning. He reports the epigastric pain is sharp, 4/10, radiating to the left arm with no alleviating or aggravating factors. Vitas on presentation showed a temperature of 98.6F, BP 108/50, heart rate 87, SpO2 94%. Labs revealed an elevated white cell count of 13.68, creatinine of 1.6, high sensitivity troponin of 105. An abdominal ultrasound was ordered which was unremarkable and CT abdomen and pelvis without contrast showing fluid filled distended loops of small bowel likely the result of an abdominal ileus. The patient continued to have worsening abdominal pain in the following days with physical exam now revealing rebound tenderness, guarding and signs of peritonitis. Leukocytosis worsened to 15.58 and surgery was consulted. The patient was taken for an exploratory laparotomy and was found to have a perforated gangrenous appendix. Conclusion: One in every 2000 adults over the age of 65 will develop appendicitis annually, making it an important cause of abdominal pain in this age group. The elderly have a higher rate of perforation at the time of presentation with one study stating that the mortality rate from perforated appendicitis in patients over the age of 80 was 21%. Elderly patient’s may not present with the classic presentation of appendicitis as seen in this case and thus, a high degree of suspicion is needed to make a prompt diagnosis. Although it is a condition we mostly see in the younger population, it is important to keep appendicitis as a differential diagnosis in the elderly

Rate control is the key-Tachycardia induced Cardiomyopathy

Introduction: Tachycardia-induced cardiomyopathy is the systolic dysfunction that results from tachyarrhythmias. It presents symptoms of heart failure and can be reversed with rate control or normalization to sinus rhythm. The aim of presenting this case report is to the awareness of tachycardia-induced cardiomyopathy, which if recognized early can be reversed by the treatment. Case Presentation: A 62-year-old male with a history of tobacco use presented with orthopnea, palpitations, and exertional dyspnea. A month ago, he was seen by his primary care physician for palpitations and was diagnosed with new-onset atrial fibrillation. There was a gradual progression of his exertional symptoms to NYHA class IV that prompted him to come to the emergency room. Upon admission, he was noted to have atrial fibrillation with the rapid ventricular response at 140 bpm. An echocardiogram revealed an LV ejection fraction of 20 % with dilated LV and RV chambers. His heart rate was controlled with metoprolol and digoxin. He was started on a heart failure regimen. Ischemic cardiac workup was unremarkable. He was subsequently followed up in the clinic. The repeat cardiac echocardiogram was noted for marked improvement of LV systolic function and of the patient\u27s symptoms. He was continued on rate control and heart failure medications. Conclusion: Tachycardia-induced cardiomyopathy can result from various tachyarrhythmias including atrial fibrillation with a rapid ventricular response. In such cases, cardiomyopathy may develop over a few weeks to over a few years. Once tachycardia-induced cardiomyopathy is suspected, treatment should focus on rate control in addition to the management of heart failure. Our case demonstrates how increased awareness of tachycardia-induced cardiomyopathy helps in timely diagnosis and can be reversible

A Case of Disseminated Cryptococcosis

Background: Cryptococcus is an invasive fungal infection, typically acquired through inhalation. It is found in soil contaminated with bird droppings and it can disseminate to the lungs, meninges, and skin. In the United States, the incidence of cryptococcosis is estimated to be about 0.4-1.3 cases per 100,000 population with the most common species being Cryptococcus Neoformans and Cryptococcus Gatti. Cryptococcosis is commonly seen in HIV patients, however, immunocompromised individuals with cancer, solid organ transplants, or chronic glucocorticoid therapy are also at high risk. Case Presentation: A 69-year-old male with history of polymyositis and granulomatosis polyangiitis on chronic steroids presents to the ER with chief complaint of progressively worsening shortness of breath and confusion of three days duration, as per patient’s wife. Patient had been noted to be more lethargic and confused with increased productive cough. Chest x-ray and high-resolution CT demonstrated bilateral dense multilobar infiltrates and he was started on Ceftriaxone, Azithromycin and Solu-Medrol for multilobar pneumonia. A serum cryptococcal antigen was ordered by infectious disease which came back positive with titers of 1:2560 and thus, he was started on Amphotericin B and Flucytosine. A lumbar puncture was then performed which showed Cryptococcal Neoformans and Cryptococcus Gatti positive in CSF. Unfortunately, the patient’s condition deteriorated, and he expired. Conclusion: Cryptococcosis predominantly occurs in HIV patients. We need to have a high index of suspicion in immunosuppressed patients including patients on chronic steroids that are at high risk of developing cryptococcosis. Prompt recognition and treatment is critical as there is a high mortality rate

PME et Territoire

L’entreprise est l’acteur opérationnel du développement, c’est le cas plus particulièrement de la PME qui constitue l’épine dorsale de toute économie. La naissance et la croissance de cette catégorie d’entreprise sont largement dépendantes de son territoire d’implantation, une dépendance qui résulte de la relation interactive entre les différents acteurs du territoire fondée sur la création collective de ressources qui constitue un facteur essentiel de l’ancrage territorial de la PME et une source de sa force et de ses particularismes. Le lien coopératif et durable entre la PME et le territoire rend l’introduction de la composante territoriale dans l’analyse de ses spécificités et de sa performance une nécessité inéluctable. Cet article a pour objectif d’élucider la relation interférente entre l’entreprise et le territoire et principalement la PME en se basant sur une grappe de références théoriques, à travers une analyse du processus de la création des liens intarissables entre les deux qui débute par des proximités en passant par des coopérations et aboutit à la génération des intérêts réciproques entre la PME et le territoire

Analysis of gene expression patterns by microarray hybridization in blood mononuclear cells of SLA-DRB1 defined Canadian Yorkshire pigs

<p>Abstract</p> <p>Background</p> <p>The Swine Leukocyte Antigen (SLA) system encodes molecules for self-nonself discrimination and is associated with immune responses and disease resistance. Three lines of pigs defined by their SLA-DRB1 alleles were developed at the University of Guelph for xenotransplantation and immune response studies. The aim of this project was to explore the potential association between defined SLA-DRB1 alleles and gene transcriptional patterns of other immune-related genes in blood mononuclear cells.</p> <p>Findings</p> <p>Three SLA-DRB1 alleles were characterized using a RT-PCR-based sequencing method. The loci represented included a new allele, DRB1*04ns01. Next, microarray heterologous (bovine-porcine) hybridization together with qPCR were used to explore differential gene expression between SLA-DRB1-defined groups. Microarray analysis showed significant (p < 0.01) differential expression for 5 genes, mostly related to inflammation. Genes varied according to the comparison analyzed. Further testing with qPCR revealed the same trend of differential expression for 4 of the genes, although statistical significance was reached for only one.</p> <p>Conclusion</p> <p>A new SLA-DRB1 allele was characterized. A potential association was found between SLA-DRB1 alleles and inflammation-related genes. However, the influence of other genes cannot be ruled out. These preliminary findings agree with other studies linking MHC haplotypes and inflammation processes, including autoimmune disease. The study provides an initial view of the biological interactions between the SLA complex and other immune-related genes. Future studies will focus on characterization of SLA-haplotypes associated with these particular alleles and the dynamics of the immune response to antigenic challenges.</p

La régionalisation avancée au Maroc : Perspectives et défis. Advanced regionalization in Morocco: Prospects and Challenges

Le Maroc a adopté beaucoup de plans de développement, qui ne lui ont pas permis d’atteindretous les objectifs escomptés d’une manière efficace dont les plus ultimes sont l’améliorationdes conditions de vie des citoyens et la réductions des disparités entre les espaces Marocains,à cause de la déclinaison des stratégies du développement telles qu’elles sont conçues auniveau central à l’échelle des régions. Dans ces conditions le territoire s’est affirmé comme unacteur du développement socio-économique capable de concevoir et de mettre en oeuvre desstratégies de développement adaptées à ses spécificités, ses moyens et aptes à répondre auxaspirations de la population locale, d’où le Maroc a procédé à la mise en oeuvre du processusde la régionalisation avancée qui met en avant le rôle de la région dans la réalisation dudéveloppement territorial endogène et équilibré. C’est un processus qui est au début et qui ades perspectives de développement prometteuses mais sa mise en oeuvre subit encore des défisà surmonter

Blind separation of convolutive mixtures of cyclostationary sources using an extended natural gradient method

An on-line adaptive blind source separation algorithm for the separation of convolutive mixtures of cyclostationary source signals is proposed. The algorithm is derived by applying natural gradient iterative learning to the novel cost function which is defined according to the wide sense cyclostationarity of signals. The efficiency of the algorithm is supported by simulations, which show that the proposed algorithm has improved performance for the separation of convolved cyclostationary signals in terms of convergence speed and waveform similarity measurement, as compared to the conventional natural gradient algorithm for convolutive mixtures