4 research outputs found
Measurement of mechanical vibrations excited in aluminium resonators by 0.6 GeV electrons
We present measurements of mechanical vibrations induced by 0.6 GeV electrons
impinging on cylindrical and spherical aluminium resonators. To monitor the
amplitude of the resonator's vibrational modes we used piezoelectric ceramic
sensors, calibrated by standard accelerometers. Calculations using the
thermo-acoustic conversion model, agree well with the experimental data, as
demonstrated by the specific variation of the excitation strengths with the
absorbed energy, and with the traversing particles' track positions. For the
first longitudinal mode of the cylindrical resonator we measured a conversion
factor of 7.4 +- 1.4 nm/J, confirming the model value of 10 nm/J. Also, for the
spherical resonator, we found the model values for the L=2 and L=1 mode
amplitudes to be consistent with our measurement. We thus have confirmed the
applicability of the model, and we note that calculations based on the model
have shown that next generation resonant mass gravitational wave detectors can
only be expected to reach their intended ultra high sensitivity if they will be
shielded by an appreciable amount of rock, where a veto detector can reduce the
background of remaining impinging cosmic rays effectively.Comment: Tex-Article with epsfile, 34 pages including 13 figures and 5 tables.
To be published in Rev. Scient. Instr., May 200
Evidence That BCL3 Plays a Role in the Etiology of Nonsyndromic Oral Clefts in Brazilian Families
The BCL3 gene has been considered a susceptibility locus for nonsyndromic cleft lip with or without cleft palate (NSCL/P), based on association and linkage studies in some populations. We evaluated an intragenic marker at the BCL3 gene and the microsatellite D19S178 (1.1 cM distant from the BCL3 gene) among 98 infants born with NSCL/P and their parents, using the transmission disequilibrium test (TDT) and a method for haplotype analysis. Our analysis, based on BCL3 alleles, revealed the existence of a marginal association of allele 135pb of the BCL3 gene with NSCL/P (w 2 = 3.60; P ¼ 0.058; 1 df), with a major effect in female (w 2 = 5.77; P ¼ 0.016; 1 df) and in familial cases (w 2 = 3.79; P ¼ 0.051; 1 df). However, the haplotype analysis detected no significant segregation distortion, even if the alleles of the D19S178 were grouped into two classes. These findings support previous findings that BCL3 plays a role in the etiology of NSCL/P as an allele of low penetrance or as a modifier locus. We hypothesize that there might be more than one mutation in this gene associated with NSCL/P, or alternatively, that more than one mutation has arisen associated with the 135-bp allele