36 research outputs found
Identification of the different sources responsible for olfactory annoyance, using an e-nose
peer reviewedaudience: researcher, professional, studen
Infantile Convulsions with Paroxysmal Dyskinesia (ICCA Syndrome) and Copy Number Variation at Human Chromosome 16p11
BACKGROUND: Benign infantile convulsions and paroxysmal dyskinesia are episodic cerebral disorders that can share common genetic bases. They can be co-inherited as one single autosomal dominant trait (ICCA syndrome); the disease ICCA gene maps at chromosome 16p12-q12. Despite intensive and conventional mutation screening, the ICCA gene remains unknown to date. The critical area displays highly complicated genomic architecture and is the site of deletions and duplications associated with various diseases. The possibility that the ICCA syndrome is related to the existence of large-scale genomic alterations was addressed in the present study. METHODOLOGY/PRINCIPAL FINDINGS: A combination of whole genome and dedicated oligonucleotide array comparative genomic hybridization coupled with quantitative polymerase chain reaction was used. Low copy number of a region corresponding to a genomic variant (Variation_7105) located at 16p11 nearby the centromere was detected with statistical significance at much higher frequency in patients from ICCA families than in ethnically matched controls. The genomic variant showed no apparent difference in size and copy number between patients and controls, making it very unlikely that the genomic alteration detected here is ICCA-specific. Furthermore, no other genomic alteration that would directly cause the ICCA syndrome in those nine families was detected in the ICCA critical area. CONCLUSIONS/SIGNIFICANCE: Our data excluded that inherited genomic deletion or duplication events directly cause the ICCA syndrome; rather, they help narrowing down the critical ICCA region dramatically and indicate that the disease ICCA genetic defect lies very close to or within Variation_7105 and hence should now be searched in the corresponding genomic area and its surrounding regions
A Constitutional Translocation t(1;17)(p36.2;q11.2) in a Neuroblastoma Patient Disrupts the Human NBPF1 and ACCN1 Genes
The human 1p36 region is deleted in many different types of tumors, and so it probably harbors one or more tumor suppressor genes. In a Belgian neuroblastoma patient, a constitutional balanced translocation t(1;17)(p36.2;q11.2) may have led to the development of the tumor by disrupting or activating a gene. Here, we report the cloning of both translocation breakpoints and the identification of a novel gene that is disrupted by this translocation. This gene, named NBPF1 for Neuroblastoma BreakPoint Family member 1, belongs to a recently described gene family encoding highly similar proteins, the functions of which are unknown. The translocation truncates NBPF1 and gives rise to two chimeric transcripts of NBPF1 sequences fused to sequences derived from chromosome 17. On chromosome 17, the translocation disrupts one of the isoforms of ACCN1, a potential glioma tumor suppressor gene. Expression of the NBPF family in neuroblastoma cell lines is highly variable, but it is decreased in cell lines that have a deletion of chromosome 1p. More importantly, expression profiling of the NBPF1 gene showed that its expression is significantly lower in cell lines with heterozygous NBPF1 loss than in cell lines with a normal 1p chromosome. Meta-analysis of the expression of NBPF and ACCN1 in neuroblastoma tumors indicates a role for the NBPF genes and for ACCN1 in tumor aggressiveness. Additionally, DLD1 cells with inducible NBPF1 expression showed a marked decrease of clonal growth in a soft agar assay. The disruption of both NBPF1 and ACCN1 genes in this neuroblastoma patient indicates that these genes might suppress development of neuroblastoma and possibly other tumor types
Search for Na in novae supported by a novel method for measuring femtosecond nuclear lifetimes
Classical novae are thermonuclear explosions in stellar binary systems, and
important sources of Al and Na. While gamma rays from the decay
of the former radioisotope have been observed throughout the Galaxy, Na
remains untraceable. The half-life of Na (2.6 yr) would allow the
observation of its 1.275 MeV gamma-ray line from a cosmic source. However, the
prediction of such an observation requires good knowledge of the nuclear
reactions involved in the production and destruction of this nucleus. The
Na()Mg reaction remains the only source of large
uncertainty about the amount of Na ejected. Its rate is dominated by a
single resonance on the short-lived state at 7785.0(7) keV in Mg. In the
present work, a combined analysis of particle-particle correlations and
velocity-difference profiles is proposed to measure femtosecond nuclear
lifetimes. The application of this novel method to the study of the Mg
states, combining magnetic and highly-segmented tracking gamma-ray
spectrometers, places strong limits on the amount of Na produced in
novae, explains its non-observation to date in gamma rays (flux < 2.5x
ph/(cms)), and constrains its detectability with future space-borne
observatories.Comment: 18 pages, 3 figures, 1 tabl
Noyaux exotiques lourds riches en protons : identification, structure et etude sel-consistante de deformation triaxiales
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Force de Coriolis et déformation nucléaire (résultats dans les isotopes de calcium et de plomb avec le multidétecteur g EUROBALL)
Ce travail de thèse porte sur l'étude de la matière nucléaire soumise à des conditions extrêmes de rotation. Grâce aux multidétecteurs g tels que EUROGAM puis EUROBALL, nous avons étudié deux régions de noyaux à haut spin en détectant leurs transitions g de désexcitation. L'influence de la force de Coriolis au niveau microscopique est mise en évidence. Les isotopes de cadmium 113-116Cd ont été peuplés par réaction de fission induite par ions lourds (28Si+176YB à 145 MeV). Des bandes découplées ont été identifiées dans les noyaux impairs atteints pour la première fois à haut spin. Considérés comme l'archétype des noyaux vibrateurs lorsqu'ils étaient étudiés par radioactivité, ils présentent à haut spin une faible déformation axiale allongée, confirmée par nos calculs microscopiques de type moyen réalisés sur les noyaux pairs-pairs. Le noyau superdéformé impair de plomb 197Pb a ensuite été atteint par réaction de fusion évaporation (18O+186W à 117 MeV). Nous avons identifié les transitions interbandes reliant ses deux bandes superdéformées partenaires en signature. La mesure expérimentale du rapport d'embranchement B(M1)/B(E2) permet d'extraire les propriétés magnétiques de la matière superdéformées, confirmant l'absence de réduction du facteur gyromagnétique de spin neutron gsn. La force de Coriolis qui découple le neutron célibataire dans les isotopes de cadmium est moins influente dans les noyaux superdéformés de plomb. Une esquisse de synthèse sur l'action de cette force de Coriolis a été présentée dans le cadre de cette étude.LYON1-BU.Sciences (692662101) / SudocSudocFranceF