The Anonymous subgraph problem.

Many problems can be modeled as the search for a subgraph S- A with specifi�c properties, given a graph G = (V;A). There are applications in which it is desirable to ensure also S to be anonymous. In this work we formalize an anonymity property for a generic family of subgraphs and the corresponding decision problem. We devise an algorithm to solve a particular case of the problem and we show that, under certain conditions, its computational complexity is polynomial. We also examine in details several specifi�c family of subgraphs

The anonymous subgraph problem

In this work we address the Anonymous Subgraph Problem (ASP). The problem asks to decide whether a directed graph contains anonymous subgraphs of a given family. This problem has a number of practical applications and here we describe three of them (Secret Santa Problem, anonymous routing, robust paths) that can be formulated as ASPs. Our main contributions are (i) a formalization of the anonymity property for a generic family of subgraphs, (ii) an algorithm to solve the ASP in time polynomial in the size of the graph under a set of conditions, and (iii) a thorough evaluation of our algorithms using various tests based both on randomly generated graphs and on real-world instances

Towards Marker-Assisted Breeding for Black Rot Bunch Resistance: Identification of a Major QTL in the Grapevine Cultivar 'Merzling'

Black rot (BR), caused by Guignardia bidwellii, is an emergent fungal disease threatening viticulture and affecting several mildew-tolerant varieties. However, its genetic bases are not fully dissected yet. For this purpose, a segregating population derived from the cross 'Merzling' (hybrid, resistant) × 'Teroldego' (V. vinifera, susceptible) was evaluated for BR resistance at the shoot and bunch level. The progeny was genotyped with the GrapeReSeq Illumina 20K SNPchip, and 7175 SNPs were combined with 194 SSRs to generate a high-density linkage map of 1677 cM. The QTL analysis based on shoot trials confirmed the previously identified Resistance to Guignardia bidwellii (Rgb)1 locus on chromosome 14, which explained up to 29.2% of the phenotypic variance, reducing the genomic interval from 2.4 to 0.7 Mb. Upstream of Rgb1, this study revealed a new QTL explaining up to 79.9% of the variance for bunch resistance, designated Rgb3. The physical region encompassing the two QTLs does not underlie annotated resistance (R)-genes. The Rgb1 locus resulted enriched in genes belonging to phloem dynamics and mitochondrial proton transfer, while Rgb3 presented a cluster of pathogenesis-related Germin-like protein genes, promoters of the programmed cell death. These outcomes suggest a strong involvement of mitochondrial oxidative burst and phloem occlusion in BR resistance mechanisms and provide new molecular tools for grapevine marker-assisted breeding

High-density linkage mapping and QTL identification of black rot resistance towards marker-assisted breeding in grapevine

Today sustainability is a pivotal objective for viticulture, but it also presents us with new challenges. The decrease in treatments has in fact changed grapevine-pathogen interactions and dynamics causing the reaffirmation of diseases previously considered secondary. This is the case of black rot (BR, caused by Phyllosticta ampelicida), which is spreading with increasing pressure in warm-humid regions causing the loss of entire crops. The interinstitutional DAMAGE project between Edmund Mach Foundation (FEM) and the Institute for Grapevine Breeding (JKI-Geilweilerhof) aims to characterize BR resistance and to develop a toolkit of molecular markers (MM) to be routinely used in marker-assisted breeding for the introgression of this trait into mildew resistant backgrounds. The first fungal strain was isolated from infected leaves collected in Trentino-Italy and mixed with a second strain isolated in southwestern Germany. This inoculum has been used to screen a segregating population derived from 'Merzling' (V. rupestris × V. lincecumii, mid-resistant) × 'Teroldego' (V. vinifera, susceptible). BR resistance phenotyping consisted of a newly developed inoculation protocol on potted plants. The F1 individuals were genotyped with the Vitis18KSNP chip and a high-density genetic map has been constructed, following the integration of 190 informative SSRs. Moreover, explorative QTL analyzes have been conducted on phenotypic data of 2020 and 2021 seasons. Finally, upon the genomic interval characterization, new MM will be designed, tested and validated on various segregating populations with different genetic backgrounds

The star formation history of the Sextans dwarf spheroidal galaxy: a true fossil of the pre-reionization era

We present the star formation history (SFH) of the Sextans dwarf spheroidal galaxy based on deep archive $B$,$I$ photometry taken with Suprime-Cam at Subaru telescope focusing our analysis on the inner region of the galaxy, fully located within the core radius. Within the errors of our SFH we have not detected any metallicity gradient along the considered radial distance interval. As a main result of this work we can state that the Sextans dwarf spheroidal stopped forming stars less than $\sim1.3$ Gyr after Big Bang in correspondance to the end of the reionization epoch. We have been able to constrain the duration of the main burst of star formation to $\sim0.6$ Gyr. From the calculation of the mechanical luminosity released from supernovae (SNe) during the brief episode of star formation, there are strong indications that SNe could have played an important role in the fate of Sextans, by removing almost completely the gas component, so preventing a prolonged star formation.Comment: 11 pages, 10 figures. Accepted for publication in MNRA

Rgb3: an organ-specific QTL for bunch resistance to black rot identified in the hybrid cultivar ‘Merzling’ Hands-on demo of the potential of Grapedia

Crops are continuously exposed to the onset of emerging diseases and the exploitation of resistance donors in breeding programs is a widely used valid strategy. In the last two decades black rot (BR), caused by the ascomycete Phyllosticta ampelicida (syn. Guignardia bidwellii), has begun to threaten European viticulture in humid continental areas due to the advent of higher temperatures which favor the pathogenic cycle of the fungus. For this reason, a program has been established for the dissection of BR resistance trait and its introgression both in Vitis vinifera varieties and mildew resistant hybrids. A preliminary study was carried out to improve germplasm screening through different approaches. Historical phenotypic and pedigree information of resistance donors were gathered to support the decision-making process in breeding. A new propagation and inoculation strategy was developed to optimize and fasten inoculation experiments. Isolates of P. ampelicida were genetically characterized and combined for the assessment of resistance independent of race-specificity. Finally, these improvements were employed first for the identification of new BR resistant parental lines and breeding selections, and then for the quantitative trait locus (QTL) analysis in a segregating population derived from the cross ‘Merzling’ (hybrid, resistant) × ‘Teroldego’ (V. vinifera, susceptible). The screening of this progeny, under green-house and field conditions, allowed the discrimination between two distinct organ-specific QTLs on chromosome 14. The previously identified Resistance to G. bidwellii (Rgb)1 locus was confirmed associated with leaf/shoot resistance, while upstream a new QTL designated Rgb3 was discovered linked to bunch resistance. Driven and inspired by the INTEGRAPE community effort that led to GRAPEDIA (GRAPEvine -omics encyclopDIA), all the available tools and resources have been exploited for the exploration of the physical region of the two QTLs, providing a hands-on demo of the potential of this portal

Highly dense linkage mapping and identification of a major QTL associated with BLACK ROT resistance in the grapevine cultivar ‘Merzling’

When the urgency of a sustainable transition comes to agriculture, one of the key areas of improvement involves the decrease of chemicals. Although vineyards cover less than 5% of agricultural land in Europe, viticulture is responsible for the use of more than 60% of all fungicides. The exploitation of grapevine varieties resistant to mildews is an efficient strategy already implemented in integrated/organic farming to reduce treatments. However, from the beginning of this century, European viticulture has been threatened by severe outbreaks of black rot (BR), an emergent and destructive disease caused by the ascomycete Phyllosticta ampelicida (sexual morph Guignardia bidwellii). These events introduced the urgent need for the introgression of BR resistance in mildew-tolerant genotypes. For this purpose, a set of parental lines and breeding selections of the Fondazione Edmund Mach has been screened for BR resistance in a growing chamber with in vivo produced spores using an optimized artificial infection protocol. Given the good performance of ‘Merzling’ (a complex genotype derived from V. vinifera and V. rupestris × V. aestivalis var. lincecumii), this cultivar was used for a cross with the susceptible variety ‘Teroldego’ (V. vinifera) and the segregating offspring was genetically characterized by means of the GrapeReSeq 18K Vitis SNP chip. Five phenotypic experiments were carried out under controlled conditions on leaves of potted plants, and three on bunches in the field. A dense genetic map was constructed combining 7,175 SNP with 194 SSR markers of a previous map. All QTL analyses revealed the presence of a strong major BR resistance locus on chromosome 14. It explains up to 45% of the trait variability (LOD 10.5) and spans a genomic region of 1.36 Mb. A specific SNP marker was found robustly associated with the resistance trait. No minor QTLs were detected. The genes underlying this region are currently under investigation via bioinformatic analysis, and microscopic inspections of disease progression are in place to understand the biological causes of the resistance trait. Finally, new molecular markers will be developed and validated on segregating populations with different genetic backgrounds, to be implemented in marker-assisted selection for BR resistance in grapevin

Lanthanide-Based Complexes Containing a Chiral trans-1,2-Diaminocyclohexane (DACH) Backbone: Spectroscopic Properties and Potential Applications

In this minireview, we give an overview on the use of the chiral molecule trans-1,2-diaminocyclohexane (DACH) in several fields of application. This chiral backbone is present in a variety of metal complexes which are employed in (enantioselective) catalysis, chiral discrimination, molecular recognition and supramolecular chemistry. Metal extraction and biochemical and pharmaceutical applications also use the DACH molecule. This contribution is particularly focused on the interesting chemical-physical properties discussed so far in the literature concerning lanthanide-based complexes containing chiral ligands characterized by the presence of DACH in the structure. In particular, the interconnection between luminescence (total and circularly polarized), structure and thermodynamics of Eu(III), Tb(III) and Sm(III) complexes will be discussed also in light of their use as optical or chiroptical probes for the sensing of important analytes dissolved in aprotic and protic polar solvents. Several complexes show potential interest in the solid state as phosphors for light emitting devices or for the detection of volatile organic compounds