Design of robust nonfragile H∞ controller for uncertain nonlinear polynomial systems

This paper is concerned with the robust H_∞ nonfragile controller design for a particular class of nonlinear systems, namely, the perturbed polynomial systems, which are subject to unstructured bounded uncertainties in both the system model and the control law. Combining the Lyapunov stability theory, properties of linear matrix inequality, and Kronecker product properties, a sufficient condition of robust H_∞ nonfragile control design is proposed. More specifically, we propose a robust H_∞ controller of nonlinear polynomial systems with additive unstructured uncertainties and variation in the control law itself that guarantee the stability and the attenuation of external perturbations. Two examples are provided to illustrate the effectiveness of the proposed approach.     

Trends in prevalence of asthma, allergic rhinitis and atopic dermatitis in 5-7-year old Swiss children from 1992 to 2001

BACKGROUND: Changing occurrence rates of asthma, allergic rhinitis and atopic dermatitis are of public health concern and require surveillance. Changes in prevalence rates of these atopic diseases were monitored during 10 years and their trend with time was determined taking into account the influence of personal and environmental risk factors. METHODS: Four cross-sectional surveys in 5-7-year old children were performed in seven different communities in Switzerland between 1992 and 2001. Prevalence of respiratory and allergic symptoms and of affecting risk factors including parental environmental concern were assessed using a standardized parental questionnaire. RESULTS: A total of 988 (74.1%), 1778 (79.0%), 1406 (82.6%) and 1274 (78.9%) children participated, respectively, in the 1992, 1995, 1998 and 2001 surveys. Prevalence rates of asthma and hay fever symptoms remained quite stable over time (wheeze/past year: 8.8%, 7.8%, 6.4% and 7.4%, sneezing attack during pollen season: 5.0%, 5.6%, 5.4% and 4.6%). Rates of reported atopic dermatitis symptoms (specific skin rash/past year: 4.6%, 6.5%,7.4% and 7.6%) showed an increase over time, but those of diagnosis of eczema did not show a clear pattern (18.4%, 15.7%, 14.0% and 15.2%). Stratified analysis by parental environmental concern and by parental atopy showed similar trends. Rates of atopic dermatitis symptoms showed significant increase in girls but stayed stable in boys. CONCLUSION: Results of these four consecutive surveys suggest that the increase in prevalence of asthma and hay fever in 5-7-year old children living in Switzerland may have ceased. However, symptoms of atopic dermatitis may still be on the rise, especially among girls.     

GJB2: the spectrum of deafness-causing allele variants and their phenotype

Genetic testing was completed on 1,294 persons with deafness referred to the Molecular Otolaryngology Research Laboratories to establish a diagnosis of DFNB1. Exon 2 of GJB2 was screened for coding sequence allele variants by denaturing high-performance liquid chromatography (DHPLC) complemented by bidirectional sequencing. If two deafness-causing mutations of GJB2 (encoding Connexin 26) were identified, further screening was not performed. If only a single deafness-causing mutation was identified, we screened for the g.1777179_2085947del (hereafter called del(GJB6-D13S1830); GenBank NT_024524.13) and mutations in the noncoding region of GJB2. Phenotype-genotype correlations were evaluated by categorizing mutations as either protein truncating or nontruncating. A total of 205 persons carried two GJB2 exon 2 mutations and were diagnosed as having DFNB1; 100 persons carried only a single deafness-causing allele variant of exon 2. A total of 37 of these persons were c.35delG carriers, and 51 carried other allele variants of GJB2. Persons diagnosed with DFNB1 segregating two truncating/nonsense mutations had a more severe phenotype than persons carrying two missense mutations, with mean hearing impairments being 88 and 37%, respectively (P < 0.05). The number of deaf c.35delG carriers was greater than expected when compared to the c.35delG carrier frequency in normal-hearing controls (P < 0.05), suggesting the existence of at least one other mutation outside the GJB2 coding region that does not complement GJB2 deafness-causing allele variants.     

Association of IL-8 (-251)T/A polymorphism with susceptibility to and aggressiveness of nasopharyngeal carcinoma

Interleukin-8 (IL-8) is an angiogenic chemokine that plays a potent role in both development and progression of many human malignancies including nasopharyngeal carcinoma (NPC). In the present study, we evaluated the susceptibility and prognostic implications of the (-251) T/A genetic variation in IL-8 in NPC. We used the allele-specific polymerase chain reaction to characterize the variation of the IL-8 promoter region for 160 unrelated Tunisian patients with NPC and 169 healthy control subjects. There was a significant association between the homozygotes IL-8 (-251) AA genotype and nasopharyngeal carcinoma (OR = 2.46; P = 0.004). The presence of the IL-8 (-251) AA genotype was highly associated with elevated NPC risk for male patients. A significant association was demonstrated between the IL-8 (-251) AA genotype and the aggressive forms of NPC as defined by large tumor size, lymph node metastasis, and advanced stages. Moreover, the presence of the IL-8 (-251) AA genotype indicated a significant association with decreased overall survival. Our findings suggest that the IL-8 promoter polymorphism is associated with increased nasopharyngeal carcinoma risk, particularly in males, as well as disease progress, supporting our hypothesis for IL-8 involvement in NPC pathogenesis.     

Effect of physical activity on bone turnover in young boys

AIMS: To evaluate the effect of the physical activity on bone turnover in young male soccer players at the Tanner's stage of 1-2. MATERIAL AND METHODS: 61 young soccer players (13,4 +/- 0,3 years old) who actively participated in soccer since 3,7 +/- 0,7 years were compared to 60 age and sex- matched non active subjects. Bone mineral density (BMD) of whole body, and in specific skeleton sites, fatty body mass (FBM) and lean body mass (LBM) were determined by a dual energy X-ray absorptiometry (DXA). Total plasma alkaline phosphatase (ALP) and plasma bone alkaline phosphatase (BALP), plasma osteocalcin (OC) and plasma collagen type I cross-linked C-telopeptide (CTX) were measured. RESULTS: BMD of the whole body and at the lumbar spine (L2-L4), femoral, lower limbs and LBM were significantly higher in young soccer players than in controls. The biochemical markers of bone turnover: ALP (6,7%), BALP (8,9%), OC (3%) and CTX (3,1%) were not significantly higher in sportsmen than in controls. The calcium was significantly higher in sportsmen than in controls. CONCLUSION: These results suggest that soccer practice induced an increase of bone mass in boys. The increase in the level of bone turnover evaluated by the new biochemical markers was not significant in the sportsmen.     

Analytical validation of a lymphocytic choriomeningitis virus real-time RT-PCR assay

Lymphocytic choriomeningitis virus (LCMV) is a rare cause of central nervous system disease in humans. Screening by real-time RT-PCR assay is of interest in the case of aseptic meningitis of unknown etiology.A specific LCMV real-time RT-PCR assay, based on the detection of genomic sequences of the viral nucleoprotein (NP), was developed to assess the presence of LCMV in cerebrospinal fluids (CSF) sent for viral screening to a Swiss university hospital laboratory.A 10-fold dilution series assay using a plasmid containing the cDNA of the viral NP of the LCMV isolate Armstrong (Arm) 53b demonstrated the high sensitivity of the assay with a lowest detection limit of ≤50 copies per reaction. High sensitivity was confirmed by dilution series assays in a pool of human CSF using four different LCMV isolates (Arm53b, WE54, Traub and E350) with observed detection limits of ≤10 PFU/ml (Arm53b and WE54) and 1 PFU/ml (Traub and E350).Analysis of 130 CSF showed no cases of acute infection. The absence of positive cases was confirmed by a published PCR assay detecting all Old World arenaviruses.This study validates a specific and sensitive real-time RT-PCR assay for the diagnosis of LCMV infections. Results showed that LCMV infections are extremely rare in hospitalized patients western in Switzerland.     

A high level of tetrasomy 9p mosaicism but no clinical manifestations other than moderate oligozoospermia with chromosomally balanced sperm: a case report

Journal of Assisted Reproduction and Genetics - Tetrasomy 9p (ORPHA: 3310) (i(9p)) is a rare chromosomal imbalance. It is characterized by the presence of a supernumerary chromosome incorporating...     

Paucisymptomatic Dermoid Cyst with Fatal Outcome

Dermoid cysts of the central nervous system can cause devastating complications because of the mass effect of meningitis due to sinus tract. We report the case of a 5‐month‐old girl who presented with a crusted lesion of the occipital region of the scalp. Clinical examination noted skin abnormalities suggestive of occult dysraphism. Magnetic resonance imaging (MRI) was recommended, however, 40 days after this evaluation, and before the MRI could be performed, the girl presented with neurologic complications. Unfortunately, the diagnosis of dermoid cyst was made after the onset of severe complications that led to her death. The findings in this case emphasize the importance of more prompt MRI evaluation, particularly in cases where cranial or spinal dysraphism is suspected to have any connection to the skin as a pit or tract. Should we perform an urgent MRI for any cutaneous sign of dysraphism to avoid a dramatic evolution?