Simple Statistical Analysis of the Impact of Some Nonidealities in Downstream VDSL with Linear Precoding

Abstract This paper considers a VDSL downstream system where crosstalk is compensated by linear precoding. Starting from a recently introduced mathematical model for FEXT channels, simple analytical methods are derived for evaluating the average bit rates achievable, taking into account three of the most important nonidealities. First, absolute and relative estimation errors in the crosstalk coefficients are discussed, and explicit formulas are obtained to express their impact. A simple approach is presented for computing the maximum line length where linear precoding overcomes the noncoordinate system. Then, the effect of out-of-domain crosstalk is analyzed. Finally, quantization errors in precoding coefficients are considered. We show that by the assumption of a midtread quantization law with different thresholds, a relatively small number of quantization bits is sufficient, thus reducing the implementation complexity. The presented formulas allow to quantify the impact of practical impairments and give a useful tool to design engineers and service providers to have a first estimation of the performance achievable in a specified scenario

Identification of pigmented Serratia marcescens symbiotically associated with Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae)

To characterize red pigment-producing bacteria (RPPB) regularly released during oviposition by red palm weevil (RPW), RPPB were recovered from eggs deposited in apples supplied as substrate for oviposition. The presence of RPPB was also detected from gut, the reproductive apparatus of dissected adult and virgin insects and from pupal cases collected within infested palms. RPPB were also identified all along the tissue of these palms. Analysis of the 16S rDNA, gyrB, rpoB, recA, and groEL sequences assigned RPPB to the species Serratia marcescens. RPPB exhibited an antimicrobial activity assessed by the agar well diffusion method against a number of gram-positive and gram-negative bacteria. In this study, we first report the identification of a red pigment-producing S. marcescens as extracellular symbiont of RPW. Route of transmission, detection within different organs, and a wide spread along the infested palm tissue, suggested S. marcescens is present as extracellular symbiont in different developmental stages of the RPW. Additionally, the antimicrobial activity exhibited versus Bacillus spp., Paenibacillus spp., and Lysinibacillus spp., reported as insect pathogens and potential candidates for biocontrol agents, could ascribe for S. marcescens a potential protective role

Clinical correlates of a subset of anti-CENP-A antibodies cross-reacting with FOXE3p53-62 in systemic sclerosis

INTRODUCTION: In a subset of patients with limited cutaneous (lc) systemic sclerosis (SSc), anti-CENP-A antibodies (Ab) cross-react with a peptide (FOXE3p53-62) that presents striking homology with one of the two immunodominant epitopes of CENP-A (Ap17-30). We searched for clinical correlates of anti-FOXE3p53-62 Ab by measuring their levels along with those of Ab to Ap17-30 and to the second immunodominant epitope of CENP-A, namely Ap1-17. METHODS: Serum samples were obtained from 121 patients with SSc, 46 patients with systemic lupus erythematosus (SLE) and 25 healthy blood donors (HBD). The reactivity of serum IgG to Ap1-17, Ap17-30 and FOXE3p53-62 was measured by ELISA. The corresponding anti-peptide Ab were affinity-purified from pooled SSc sera and used to establish standard curves for quantifying these Ab in patients and HBD. Receiver operating characteristics (ROC) analysis, comparing SSc patients who were positive for anti-CENP Ab (ACA+) to those who were negative, was used to find cut-off points for dichotomizing the anti-peptide Ab levels into positive and negative. Clinical records were reviewed to extract demographic data and information about organ involvement and disease activity. RESULTS: Of 121 SSc sera, 75 were ACA+; 88.0% of these samples reacted with Ap1-17, 82.6% with Ap17-30 and 53.3% with FOXE3p53-62. Among the 46 ACA- SSc sera, 2.2% reacted with Ap1-17, 4.3% with Ap17-30 and 11% with FOXE3p53-62. The levels of these Ab were low in ACA-, SLE and HBD groups and not significantly different among them. When ACA+ SSc patients were divided into subgroups positive or negative for anti-FOXE3p53-62 Ab, the only variables that were significantly different between groups were the levels of anti-Ap17-30 Ab and disease activity index (DAI). There was a significant association between negativity for anti-FOXE3p53-62 Ab and active disease defined as either DAI ≥3 (Fisher exact test, P = 0.045) or less restrictive DAI≥2.5 (P = 0.009). CONCLUSIONS: ACA+-Anti-FOXE3p53-62+Ab identifies a subgroup of patients with lcSSc who are less likely to develop active disease. In lc SSc patients at presentation, anti-FOXE3p53-62+ can be a marker with prognostic significance

Isolation And molecular characterization of xylella fastidiosa from different host plant species in Italy (Apulia region)

L'isolement en culture pure de la souche Xylella fastidiosa liée au syndrome de déclin rapide de l'olivier (OQDS), récemment observé dans les Pouilles (sud de l'Italie) a été tenté à partir des plantes symptomatiques naturellement infectée, principalement Olea europaea L., Polygala myrtifolia et Rosmarinus officinalis, en utilisant les méthodes d'impression et d'extraction de la sève. Avant l'isolement, RT-LAMP et qPCR ont été utilisés pour déterminer la présence de X. fastidiosa chez tous les hôtes. Des cultures bactériennes pures ont été obtenues à partir d'extraits d'Olea europaea L. et de Polygala myrtifolia étalés dans un milieu tamponné d'extrait de cystéine-levure (BCYE). Deux isolats d'olive ont ensuite été typés à l'aide du système de séquençage multilocus (MLST). Les résultats indiquent qu'Olea europaea a un grand potentiel d'isolement, et la méthode d'impression a présenté des résultats nettement meilleurs. MLST montre des points communs génétiques avec la souche De Donno (ST53) et confirme que nous avons toujours le même type de séquence ST53 dans la région.Pure culture isolation of the Xylella fastidiosa strain related to the olive quick declinesyndrome (OQDS), lately noticed in Apulia (southern Italy) was attempted fromnaturally infected symptomatic plants mainly Olea europaea L., Polygala myrtifolia and Rosmarinus officinalis using printing and sap extraction methods. Prior to isolation, RTLAMP and qPCR were used to determine the presence of Xylella fastidiosa in all hosts. Pure bacterial cultures were obtained from both Olea europaea L. and Polygala myrtifolia extracts plated in buffered cysteine-yeast extract (BCYE) media. Two olive isolates were subsequently typed using the Multilocus Sequencing System (MLST). Findings indicate that beside Olea europaea, Polygala myrtifolia seems to have a good potential for isolation, and printing method has presented significantly better results. MLST shows genetic commonality with De Donno (ST53) strain and ascertain that Apulia region still have the same sequence type ST53 in the region

Direct tissue blot immunoassay for detection of Xylella fastidiosa in olive trees

A direct tissue blot immunoassay (DTBIA) technique has been compared with ELISA and PCR for detection of Xylella fastidiosa in olive trees from Apulia (southern Italy). Fresh cross-sections of young twigs and leaf petioles were printed onto nitrocellulose membranes and analyzed in the laboratory. Analyses of a first group of 61 samples gave similar efficiency for the three diagnostic techniques for detection the bacterium (24 positive and 36 negative samples), except for a single sample which was positive only with DTBIA and PCR. Similar results were obtained by separately analyzing suckers and twigs collected from different sectors of tree canopies of a second group of 20 olive trees (ten symptomatic and ten symptomless). In this second test the three diagnostic techniques confirmed the irregular distribution of the bacterium in the tree canopies and erratic detectability of the pathogen in the young suckers. It is therefore necessary to analyse composite samples per tree which should be prepared with twigs collected from different sides of the canopy. The efficiency comparable to ELISA and PCR, combined with the advantages of easier handling, speed and cost, make DTBIA a valid alternative to ELISA in large-scale surveys for occurrence of X. fastidiosa. Moreover, the printing of membranes directly in the field prevents infections spreading to Xylella-free areas, through movement of plant material with pathogen vectors for laboratory testing

Direct tissue blot immunoassay for detection of Xylella fastidiosa in olive trees

A direct tissue blot immunoassay (DTBIA) technique has been compared with ELISA and PCR for detection of Xylella fastidiosa in olive trees from Apulia (southern Italy). Fresh cross-sections of young twigs and leaf petioles were printed onto nitrocellulose membranes and analyzed in the laboratory. Analyses of a first group of 61 samples gave similar efficiency for the three diagnostic techniques for detection the bacterium (24 positive and 36 negative samples), except for a single sample which was positive only with DTBIA and PCR. Similar results were obtained by separately analyzing suckers and twigs collected from different sectors of tree canopies of a second group of 20 olive trees (ten symptomatic and ten symptomless). In this second test the three diagnostic techniques confirmed the irregular distribution of the bacterium in the tree canopies and erratic detectability of the pathogen in the young suckers. It is therefore necessary to analyse composite samples per tree which should be prepared with twigs collected from different sides of the canopy. The efficiency comparable to ELISA and PCR, combined with the advantages of easier handling, speed and cost, make DTBIA a valid alternative to ELISA in large-scale surveys for occurrence of X. fastidiosa. Moreover, the printing of membranes directly in the field prevents infections spreading to Xylella-free areas, through movement of plant material with pathogen vectors for laboratory testing

Optimisation of sampling and testing for asymptomatic olive trees infected by Xylella fastidiosa in Apulia region, Italy

Early detection of Xylella fastidiosa outbreaks in Apulian olive groves is crucial, especially in buffer zones and pathogen-free areas where olive trees are asymptomatic. Three studies were conducted. Two were on the spatial and temporal progression of X. fastidiosa infections in tree canopies of asymptomatic or mildly symptomatic olive trees of tolerant ('Leccino') and susceptible ('Cellina di Nardò' and 'Ogliarola salentina') cultivars. Despite different trends in pathogen infection rates and concentrations between 'Leccino' and susceptible olive cultivars over the study period, results showed that sampling was most effective in the mid-upper part of tree canopies throughout the year, excluding the warmest and coldest periods. Stem xylem tissues were the most appropriate for detecting the pathogen compared to lower parts of mature leaves with petioles, using serological and molecular assays. Based on these results, a third study was conducted to compare molecular and serological tests (qPCR, real-time LAMP, DAS-ELISA, DTBIA) for detection of X. fastidiosa in the mid-upper part of asymptomatic branches of infected 'Leccino' trees that were sampled in an appropriate collection time, using stem xylem tissue as the most appropriate matrix for testing. The molecular methods showed the greatest sensitivity, with no undetermined results, while among the serological assays, DTBIA was more sensitive than DAS-ELISA. An improved protocol for monitoring asymptomatic olive trees is recommended

Libertatis dulcedo. Omaggio di allievi e amici a Giovannella Cresci Marrone

Nel 2021 Giovannella Cresci Marrone, Professore Ordinario di Storia Romana presso l’Università Ca’ Foscari Venezia, è andata in pensione. Il volume ripercorre i suoi diversi interessi, attraverso la prospettiva di colleghi che con lei hanno condiviso esperienze particolarmente importanti dal punto di vista professionale e personale. All’indagine dei nuclei tematici che hanno caratterizzato la sua attività di ricerca segue una riflessione sugli aspetti maggiormente innovativi della sua didattica e del suo impegno istituzionale. Il volume si configura come un riconoscimento del fondamentale ruolo che Giovannella ha rivestito per i suoi numerosi allievi, i suoi moltissimi studenti e per tutti coloro che hanno in diversi modi potuto trarre profitto dal suo magistero.This book is a collection of essays in honour of Giovannella Cresci Marrone, Professor of Roman History at Ca’ Foscari University of Venice, on the occasion of her retirement on 1 October 2021. The volume explores Giovannella’s interests through the eyes of a group of colleagues, who, over the years and since the very beginning of her academic career, have shared with her significant experiences in a professional and personal capacity. The essays cover the main domains of Giovannella’s scientific research: epigraphy and regional history, ancient writing cultures, historiography and political history, from the Greek classical period to the uses of the past in the twentieth century. Specific attention is given to the multiple patterns through which different areas of Italy were incorporated into the Roman world and to the scrutiny of several key figures of ancient history, such as Themistocles, Alexander the Great, Caesar, and Augustus, as well as their receptions. They also consider Giovannella’s innovative teaching methodologies and her commitment to the institutions at which she worked. The book is conceived as a tribute to the crucial role that Giovannella has played for her many pupils, for her countless students, and for all those who have had the privilege of benefiting in different ways from her mentorship

Surveys of potato-growing areas and surface water in Lebanon for potato brown and ring rot pathogens.

Field surveys were carried out over three growing seasons (2013\u20132015), in the main potato growing areas of Lebanon, to assess the occurrence of potato brown rot caused by Ralstonia solanacearum and potato ring rot caused by Clavibacter michiganensis subsp. sepedonicus. A total of 232 potato samples were collected from Bekaa valley and 145 samples from Akkar plain, which are the largest Lebanese areas cropped with potatoes. Composite samples of 200 potato tubers were randomly collected from each field, following procedures laid down in EU legislation. Twelve potato demonstration fields were established in Akkar plain and designed for potato export to European markets: these were also surveyed using the same strategy. Furthermore, a network of 40 sampling sites in Bekaa and 19 sites in Akkar was established to collect surface water. GPS coordinates of potato fields and water sampling sites were recorded to map specific sampling points using Geographic Information System. All samples gave negative results for R. solanacearum and C. michiganensis subsp. sepedonicus in potatoes and R. solanacearum in water, as indicated using the official EU methods for detection and diagnosis for these pathogens. A monitoring system for R. solanacearum and C. michiganensis subsp. michiganensis has been set up in Lebanon. This will increase the phytosanitary quality of potatoes and provide access to broader international markets