Continuous control of ionization wave chaos by spatially derived feedback signals

In the positive column of a neon glow discharge, two different types of ionization waves occur simultaneously. The low-dimensional chaos arising from the nonlinear interaction between the two waves is controlled by a continuous feedback technique. The control strategy is derived from the time-delayed autosynchronization method. Two spatially displaced points of observation are used to obtain the control information, using the propagation characteristics of the chaotic wave.Comment: Elsevier-Tex-File, 8 pages, 6 figures, submitted to PL

Ionization waves: from stability to chaos and turbulence

International audienc

Controlling the Chaotic Regime of Nonlinear Ionization Waves using the Time-Delay Autosynchronization Method

International audienc

Clinical profile of children with haemophilia at the University Hospital of Brazzaville

Haemophilia is a rare hereditary haemorrhagic disease caused by coagulation factor VIII (haemophilia A) or IX (haemophilia B) deficiency. Very few data exist on this disease in Congo. This survey aims to describe the epidemiological and clinical aspects of the children affected

The pathology of the eyelid at the University Hospital of Brazzaville

Background: The eyelids have two essential roles, protecting the eye from external attacks and ensure the drainage of tears through the nasolacrimal passages they shelter. Eyelids may be the site of many diseases.Objective: To determine the main pathologies of eyelid in University Hospital of Brazzaville.Design: Cross-sectional study.Subjects: Records of patients seen for a disease of the eyelids.Results: One hundred and twelve cases were studied. The pathologies found were: Trauma (40.18%), Infections (22.32%), Tumours (17.87%), Paralysis of III nerve(7,14%) Paralysis of VII nerve (6.25%), Myasthenia gravis (2.67% ), Steinert myopathy (2.67% ), Cryptophthalmos due to Fraser's syndrome (0.90% ). Domestic violence topped trauma (31 patients I 45). Infections were dominated by ophthalmic Zona (18 patients I 25) and two rare diseases, one case of North American blastomycosis and one case of post surgical eyelid gangrene. Basal cell carcinoma was the first cancer (11 patients I 20).Conclusion: The pathologies of eyelid is rich and varied. In Brazzaville it is dominated by trauma and infections

Pregnancy Outcomes among Patients with Sickle Cell Disease in Brazzaville

Introduction. Sickle cell disease (SCD) is one of the most common genetic diseases in the world. It combines, in its homozygous form, chronic hemolytic anemia, vasoocclusive complications, and susceptibility to infections. It is well known that the combination of pregnancy and sickle cell disease promotes the occurrence of complications that are sometimes fatal for the mother and/or the fetus. Objective. The objective of the current study was to compare pregnancy outcomes among women with SCD with those of women without the diagnosis of SCD. Materials and methods. It was a case-control study carried out in four maternity hospitals in Brazzaville in 2 years (July 2017–June 2019). It concerned 65 parturients with SS homozygous SCD. The mode of childbirth and maternal and perinatal morbidity and mortality were compared with those of 130 non-sickle cell pregnant women. Results. The average age was 27 years for SCD women and 31 years for non-SCD women. The average gestational age at delivery was 35 weeks for SCD women and 38 weeks for non-SCD women. From the logistic regression analysis using the comparison group as the reference group, there was excessive risk in SCD compared to non-SCD of infection (29.3% vs. 4.6%, OR = 21.7, 95% CI [7.6–62.7]; p=0.001), cesarean (63% vs. 35.4%, OR = 3.1, 95% CI [1.6–5.7]; p=0.001), prematurity (75.4% vs. 30.8%, OR = 8, 95% CI [3.0–23.2]; p=0.001), low birth weight (52.3% vs. 16.1%, OR = 4.7, 95% CI [2.4–9.4]; p=0.001), neonatal requiring admission to the intensive care unit (40.3% vs. 17.5%, OR = 3.2, 95% CI [1.6–6.3]; p=0.01), and neonatal death (21.5% vs. 4.8%, OR = 4.3, 95% CI [1.5–12.2]; p=0.01). Conclusion. The risk of pregnancy in patients with homozygous sickle cell anemia remains high, on both the maternal and fetal sides