12 research outputs found
On the Perturbative Stability of the QCD Predictions for the Ratio in Heavy-Quark Leptoproduction
We analyze the perturbative and parametric stability of the QCD predictions
for the Callan-Gross ratio in heavy-quark leptoproduction.
We consider the radiative corrections to the dominant photon-gluon fusion
mechanism. In various kinematic regions, the following contributions are
investigated: exact NLO results at low and moderate ,
asymptotic NLO predictions at high , and both NLO and NNLO
soft-gluon (or threshold) corrections at large Bjorken . Our analysis shows
that large radiative corrections to the structure functions and
cancel each other in their ratio with good accuracy. As
a result, the NLO contributions to the Callan-Gross ratio are less than 10% in
a wide region of the variables and . We provide compact LO predictions
for in the case of low . A simple formula connecting the
high-energy behavior of the Callan-Gross ratio and low- asymptotics of the
gluon density is derived. It is shown that the obtained hadron-level
predictions for are stable under the DGLAP evolution of the
gluon distribution function. Our analytic results simplify the extraction of
the structure functions and from measurements of
the corresponding reduced cross sections, in particular at DESY HERA.Comment: 14 pages, 6 figures, revtex4; minor correction
[Reconstruction of sexual offences--forensic aspects of sperm traces]
The investigation of sexual offences is a real challenge, as the injuries are often unspecific or faint and may sometimes be missing completely. Evidence recovery and analysis as well as the statements of the victims and suspects are therefore of vital importance. In both presented cases, the results of trace evidence analysis were basically consistent with a sexual assault, but the victims' statements regarding the course of events and the pattern of traces showed severe discrepancies
Allelic proportions of 16 STR lociâincluding the new European Standard Set (ESS) lociâin a Swiss population sample
Allele frequencies and forensically relevant population statistics of 16 STR loci, including the new European Standard Set (ESS) loci, were estimated from 668 unrelated individuals of Caucasian appearance living in different parts of Switzerland. The samples were amplified with a combination of the following three kits: AmpFlSTRÂź NGM SElect?, PowerPlexÂź ESI17 and PowerPlexÂź ESX 17. All loci were highly polymorphic and no significant departure from Hardy-Weinberg equilibrium and linkage equilibrium was detected after correction for sampling
Species identification of protected carpet pythons suitable for degraded forensic samples
High-Resolution Melting of 12S rRNA and Cytochrome b DNA Sequences for Discrimination of Species within Distinct European Animal Families
A global analysis of Y-chromosomal haplotype diversity for 23 STR loci
In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent
DNA typing in wildlife crime : recent developments in species identification
Species identification has become a tool in the investigation of acts of alleged wildlife crimes. This review details the steps required in DNA testing in wildlife crime investigations and highlights recent developments where not only can individual species be identified within a mixture of species but multiple species can be identified simultaneously. âWhat species is this?â is a question asked frequently in wildlife crime investigations. Depending on the material being examined, DNA analysis may offer the best opportunity to answer this question. Species testing requires the comparison of the DNA type from the unknown sample to DNA types on a database. The areas of DNA tested are on the mitochondria and include predominantly the cytochrome b gene and the cytochrome oxidase I gene. Standard analysis requires the sequencing of part of one of these genes and comparing the sequence to that held on a repository of DNA sequences such as the GenBank database. Much of the DNA sequence of either of these two genes is conserved with only parts being variable. A recent development is to target areas of those sequences that are specific to a species; this can increase the sensitivity of the test with no loss of specificity. The benefit of targeting species specific sequences is that within a mixture of two of more species, the individual species within the mixture can be identified. This identification would not be possible using standard sequencing. These new developments can lead to a greater number of samples being tested in alleged wildlife crimes