Effect of the nucleon-delta interaction on properties of the three-nucleon ground state

Wave-function components containing a single Δ isobar are included in the calculation of the three-nucleon bound state. In extension to previous work, a nucleon-Δ potential based on meson exchange is incorporated in the interaction models. The interaction models are constructed phase equivalent with the purely nucleonic Paris and Bonn one boson exchange potential in q space (OBEPQ) potentials. The nucleon-Δ potential yields an additional contribution of the order of 0.1–0.2 MeV to the effective three-nucleon force. Its effect on the electromagnetic properties of the three-nucleon bound state is also considered and found to be small

Does it make sense to talk about NΔ phase shifts?

The question of whether one can consistently define and extract nucleon-delta scattering parameters, phase shifts, and inelasticities from the partial-wave NN→NΔ amplitudes is discussed. We have studied the unitarity relation and identified the conditions under which the extraction of such quantities is meaningful. Then these conditions were tested in several coupled-channel models of the NN-NΔ system

A Unique Mutation in a MYB Gene Cosegregates with the Nectarine Phenotype in Peach

Nectarines play a key role in peach industry; the fuzzless skin has implications for consumer acceptance. The peach/nectarine (G/g) trait was described as monogenic and previously mapped on chromosome 5. Here, the position of the G locus was delimited within a 1.1 cM interval (635 kb) based on linkage analysis of an F2 progeny from the cross \u2018Contender\u2019 (C, peach) x \u2018Ambra\u2019 (A, nectarine). Careful inspection of the genes annotated in the corresponding genomic sequence (Peach v1.0), coupled with variant discovery, led to the identification of MYB gene PpeMYB25 as a candidate for trichome formation on fruit skin. Analysis of genomic re-sequencing data from five peach/nectarine accessions pointed to the insertion of a LTR retroelement in exon 3 of the PpeMYB25 gene as the cause of the recessive glabrous phenotype. A functional marker (indelG) developed on the LTR insertion cosegregated with the trait in the CxA F2 progeny and was validated on a broad panel of genotypes, including all known putative donors of the nectarine trait. This marker was shown to efficiently discriminate between peach and nectarine plants, indicating that a unique mutational event gave rise to the nectarine trait and providing a useful diagnostic tool for early seedling selection in peach breeding programs

L'origine delle nettarine nella mutazione di un singolo gene MYB.

non present

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation; analyses timings and patterns of tumour evolution; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity; and evaluates a range of more-specialized features of cancer genomes