17 research outputs found
Baryonic Regge trajectories with analyticity constraints
A model for baryonic Regge trajectories compatible with the threshold
behavior required by unitarity and asymptotic behavior in agreement with
analyticity constraints is given in explicit form. Widths and masses of the
baryonic resonances on the N and trajectories are reproduced. The
MacDowell symmetry is exploited and an application is given.Comment: 12 pages, 6 figure
Characterization of Two New York City Jewish Populations at Six Short Tandem Repeat Loci
The Hasidic and non-Hasidic Jewish communities of New York City represent two subpopulations with long-documented histories of restrictive marriage patterns and a high degree of endogamy. As part of a continuing study into their genetic structure, allele frequencies were determined for the six tetrameric short tandem repeat (STR) loci: FESFPS, F13AO1, vWA, CSF1PO, TPOX, and THO1. All loci were tested for Hardy-Weinberg equilibrium (HWE) by three tests; chi-square analysis, Monte Carlo chi-square analysis, and the exact test. The non-Hasidic population failed to meet HWE at the F13A01, FESFPS, and CSF1PO loci by all three tests. The Hasidic population also failed to meet HWE at the same loci by some of the tests. Comparison of the Hasidic to the non-Hasidic population using an R Ă— C contingency table demonstrated a similarity at only the vWA locus. Significant differences exist when comparing the two Jewish populations to a reference Caucasian population
Determination of Deposition Order of Toners, Inkjet Inks, and Blue Ballpoint Pen Combining MeV-Secondary Ion Mass Spectrometry and Particle Induced X-ray Emission
Determination of the deposition order of different writing tools is very important for the forensic investigation of questioned documents. Here we present a novel application of two ion beam analysis (IBA) techniques: secondary ion mass spectrometry using MeV ions (MeV-SIMS) and particle induced X-ray emission (PIXE) to determine the deposition order of intersecting lines made of ballpoint pen ink, inkjet printer ink, and laser printer toners. MeV-SIMS is an emerging mass spectrometry technique where incident heavy MeV ions are used to desorb secondary molecular ions from the uppermost layers of an organic sample. In contrast, PIXE provides information about sample elemental composition through characteristic X-ray spectra coming from greater depth. In the case of PIXE, the information depth depends on incident ion energy, sample matrix and self-absorption of X-rays on the way out from the sample to the X-ray detector. The measurements were carried out using a heavy ion microprobe at the Ruđer Bošković Institute. Principal component analysis (PCA) was employed for image processing of the data. We will demonstrate that MeV-SIMS alone was successful to determine the deposition order of all intersections not involving inkjet printer ink. The fact that PIXE yields information from deeper layers was crucial to resolve cases where inkjet printer ink was included due to its adherence and penetration properties. This is the first time the different information depths of PIXE and MeV-SIMS have been exploited for a practical application. The use of both techniques, MeV-SIMS and PIXE, allowed the correct determination of deposition order for four out of six pairs of samples
Persistence of plant DNA sequences in the blood of dairy cows fed with genetically modified (Bt176) and conventional corn silage
Chantier qualité GAInternational audienceTo determine whether plant sequences, including transgenic sequences, are present in animal blood, we tested blood samples from Holstein cows fed with either Bt176 genetically modified corn or conventional corn. We used previously described sensitive real-time PCR assays targeting transgenic sequences (35S promoter and Bt176 specific junction sequence), a monocopy maize-specific sequence (ADH promoter), and two multicopy sequences from plant nucleus (26S rRNA gene) and chloroplast (psaB gene). The presence of Cry1A(b) protein in bovine blood samples was also tested using a sandwich ELISA kit. Our study shows the ability of plant nuclear and/or chloroplast DNA fragments to enter bovine blood circulation. However, maize nuclear DNA, both mono- and multicopy sequences, was less detected than chloroplast DNA, probably because the higher number of chloroplast copies and also possibly because nuclear DNA might be less protected by the nuclear membrane. Despite our data confirm the ability of small (ca.150 bp) plant DNA fragments to cross the intestinal barrier, we were unable to demonstrate clearly the presence of transgenic DNA or proteins in bovine blood. No sample tested positive with the two real-time PCR assays targeting transgenic sequences (35S promoter and Bt176 specific junction sequence). Only faint punctual positive results occurred randomly and were probably due to postsample collection or laboratory contamination or can be considered as artifact as they have never been confirmed. Our data highlight the difficulties to detect transgenic sequences in blood of dairy cows fed genetically modified corn (Bt176) silage. Those results show that in order to meet the consumers’ demand of animals fed with GM products there is currently no cost-effective analytical procedure to replace documentary traceability