Non-linear MRD codes from cones over exterior sets

By using the notion of $d$-embedding $\Gamma$ of a (canonical) subgeometry $\Sigma$ and of exterior set with respect to the $h$-secant variety $\Omega_{h}(\mathcal{A})$ of a subset $\mathcal{A}$, $0 \leq h \leq n-1$, in the finite projective space $\mathrm{PG}(n-1,q^n)$, $n \geq 3$, in this article we construct a class of non-linear $(n,n,q;d)$-MRD codes for any $2 \leq d \leq n-1$. A code $\mathcal{C}_{\sigma,T}$ of this class, where $1\in T \subset \mathbb{F}_q^*$ and $\sigma$ is a generator of $\mathrm{Gal}(\mathbb{F}_{q^n}|\mathbb{F}_q)$, arises from a cone of $\mathrm{PG}(n-1,q^n)$ with vertex an $(n-d-2)$-dimensional subspace over a maximum exterior set $\mathcal{E}$ with respect to $\Omega_{d-2}(\Gamma)$. We prove that the codes introduced in [Cossidente, A., Marino, G., Pavese, F.: Non-linear maximum rank distance codes. Des. Codes Cryptogr. 79, 597--609 (2016); Durante, N., Siciliano, A.: Non-linear maximum rank distance codes in the cyclic model for the field reduction of finite geometries. Electron. J. Comb. (2017); Donati, G., Durante, N.: A generalization of the normal rational curve in $\mathrm{PG}(d,q^n)$ and its associated non-linear MRD codes. Des. Codes Cryptogr. 86, 1175--1184 (2018)] are appropriate punctured ones of $\mathcal{C}_{\sigma,T}$ and solve completely the inequivalence issue for this class showing that $\mathcal{C}_{\sigma,T}$ is neither equivalent nor adjointly equivalent to the non-linear MRD code $\mathcal{C}_{n,k,\sigma,I}$, $I \subseteq \mathbb{F}_q$, obtained in [Otal, K., \"Ozbudak, F.: Some new non-additive maximum rank distance codes. Finite Fields and Their Applications 50, 293--303 (2018).]

On the classification of low degree ovoids of Q+(5,q)Q^+(5,q)

Ovoids of the Klein quadric $Q^+(5,q)$ of $\mathrm{PG}(5,q)$ have been studied in the last 40 year, also because of their connection with spreads of $\mathrm{PG}(3,q)$ and hence translation planes. Beside the classical example given by a three dimensional elliptic quadric (corresponding to the regular spread of $\mathrm{PG}(3,q)$) many other classes of examples are known. First of all the other examples (beside the elliptic quadric) of ovoids of $Q(4,q)$ give also examples of ovoids of $Q^+(5,q)$. Another important class of ovoids of $Q^+(5,q)$ is given by the ones associated to a flock of a three dimensional quadratic cone. To every ovoid of $Q^+(5,q)$ two bivariate polynomials $f_1(x,y)$ and $f_2(x,y)$ can be associated. In this paper, we classify ovoids of $Q^+(5,q)$ such that $f_1(x,y)=y+g(x)$ and $\max\{deg(f_1),deg(f_2)\}<(\frac{1}{6.3}q)^{\frac{3}{13}}-1$, that is $f_1(x,y)$ and $f_2(x,y)$ have "low degree" compared with $q$.Comment: Submitted to Journal of Algebraic Combinatorics. arXiv admin note: substantial text overlap with arXiv:2203.1468

Transcatheter Ablation of Atrial Fibrillation in Patients with Chronic Heart Failure

Atrial fibrillation (AF) is the most frequent of all cardiac arrhythmias and it is associated with an increased risk of stroke, systemic embolism and heart failure. Patients with AF have a twofold increased risk of death and fivefold increased risk of stroke compared with those without AF. In patients with heart failure (HF), AF ablation improves left ventricular (LV) function over short- and long-term follow-ups, especially compared with medical treatment. Furthermore, AF ablation in HF patients relates to a significant improvement in quality of life, functional class and exercise tolerance, possibly related to the improvement in LV function and hemodynamic status of the patients. Finally, data showed that restoration of sinus rhythm in this setting of patients reduced the incidence of stroke and death. In this review, we reported all the major data regarding atrial fibrillation therapy in patients with heart failure

Integrating spatially-and temporally-heterogeneous data on river network dynamics using graph theory

: The study of non-perennial streams requires extensive experimental data on the temporal evolution of surface flow presence across different nodes of channel networks. However, the consistency and homogeneity of available datasets is threatened by the empirical burden required to map stream network expansions and contractions. Here, we developed a data-driven, graph-theory framework aimed at representing the hierarchical structuring of channel network dynamics (i.e., the order of node activation/deactivation during network expansion/retraction) through a directed acyclic graph. The method enables the estimation of the configuration of the active portion of the network based on a limited number of observed nodes, and can be utilized to combine datasets with different temporal resolutions and spatial coverage. A proof-of-concept application to a seasonally-dry catchment in central Italy demonstrated the ability of the approach to reduce the empirical effort required for monitoring network dynamics and efficiently extrapolate experimental observations in space and time

Obstructing left sided colorectal cancer. A retrospective single center study.

Background: In recent years, with population aging, there has been an increased number of colorectal cancer cases in elderly patients with severe occlusion symptoms. About 75% of obstructions due to malignant colorectal cancer (10-30%) occur distal to splenic flexure. Methods: The authors evaluated the best surgical therapeutic strategy to be used in cases of left-sided colorectal carcinoma in patients over 65 years old, especially considering the emergency condition, age of patients and efficacy in terms of postoperative morbidity, mortality and 5 years survival rate. Results: The management of left-sided obstructing colorectal carcinoma is controversial. Hartmann’s procedure is the best therapeutic choice in elderly patients. However, resection with intraoperative colonic wash-out and primary anastomosis has favorable outcome in low risk patients. Conclusions: A review of the literature reveals that primary resection and anastomosis for left-sided obstructing CRC is the correct therapeutic strategy in low risk patients with localized, resectable carcinoma, without peritonitis; Hartmann’s procedure should be adopted in doubtful cases and in high risk patients

Do BRAF inhibitors select for populations with different disease progression kinetics?

Ipilimumab, an anti-CTLA-4 monoclonal antibody, has been shown to improve overall survival in patients with metastatic melanoma. Preliminary data suggest that patients who fail BRAF inhibitor treatment experience a very rapid progression of disease. Such selectivity for more rapid disease progression may mean these patients do not receive the same benefit from subsequent treatment with ipilimumab as patients without prior BRAF inhibitor treatment. The current challenge is focused on how to identify and approach the two populations of fast and slow progressors and recent hypothesis suggest that treatment choice could be guided by baseline risk factors. However, no data have yet defined which the best sequence is and more research is needed to identify predictors of response in patients with metastatic melanoma to help guide whether a BRAF inhibitor or ipilimumab should be used first in sequential therapy

Open Surgery for Sportsman's Hernia a Retrospective Study

Sportsman's hernia is a painful syndrome in the inguinal area occurring in patients who play sports at an amatorial or professional level. Pain arises during sport, and sometimes persists after activity, representing an obstacle to sport resumption. A laparoscopic/endoscopic approach is proposed by many authors for treatment of the inguinal wall defect. Aim of this study is to assess the open technique in terms of safety and effectiveness, in order to obtain the benefit of an open treatment in an outpatient management. From October 2017 to July 2019, 34 patients underwent surgery for groin pain syndrome. All cases exhibited a bulging of the inguinal posterior wall. 14 patients were treated with Lichtenstein technique with transversalis fascia plication and placement of a polypropylene mesh fixed with fibrin glue. In 20 cases, a polypropylene mesh was placed in the preperitoneal space. The procedure was performed in day surgery facilities. Early or late postoperative complications did not occur in both groups. All patients returned to sport, in 32 cases with complete pain relief, whereas 2 patients experienced mild residual pain. The average value of return to sport was 34.11 ± 8.44 days. The average value of return to play was 53.82 ± 11.69 days. With regard to postoperative pain, no substantial differences between the two techniques were detected, and good results in terms of the resumption of sport were ensured in both groups. Surgical treatment for sportsman's hernia should be considered only after the failure of conservative treatment. The open technique is safe and allows a rapid postoperative recovery

Zero Fluoroscopy Arrhythmias Catheter Ablation: A Trend Toward More Frequent Practice in a High-Volume Center

BACKGROUND: Awareness of radiation exposure risks associated to interventional cardiology procedures is growing. The availability of new technologies in electrophysiology laboratories has reduced fluoroscopy usage during arrhythmias ablations. The aim of this study was to describe procedures with and without X-Rays and to assess feasibility, safety, and short-term efficacy of zero fluoroscopy intervention in a high-volume center oriented to keep exposure to ionizing radiation as low as reasonably achievable. METHODS: Cardiac catheter ablations performed in our hospital since January 2017 to June 2021. RESULTS: A total of 1,853 procedures were performed with 1,957 arrhythmias treated. Rate of fluoroless procedures was 15.4% (285 interventions) with an increasing trend from 8.5% in 2017 to 22.9% of first semester 2021. The most frequent arrhythmia treated was atrial fibrillation (646; 3.6% fluoroless) followed by atrioventricular nodal reentrant tachycardia (644; 16.9% fluoroless), atrial flutter (215; 8.8% fluoroless), ventricular tachycardia (178; 17.4% fluoroless), premature ventricular contraction (162; 48.1% fluoroless), and accessory pathways (112; 31.3% fluoroless). Although characteristics of patients and operative details were heterogeneous among treated arrhythmias, use of fluoroscopy did not influence procedure duration. Moreover, feasibility and efficacy were 100% in fluoroless ablations while the rate of major complications was very low and no different with or without fluoroscopy (0.45 vs. 0.35%). CONCLUSION: Limiting the use of X-Rays is necessary, especially when the available technologies allow a zero-use approach. A lower radiation exposure may be reached, reducing fluoroscopy usage whenever possible during cardiac ablation procedures with high safety, full feasibility, and efficacy

Materiali di lavoro per una ricerca sugli ambienti organizzati di fronte al problema dell'immigrazione straniera

Working Paper ; n.108- Indice #5- Organizzazioni e atteggiamenti #9- Atteggiamenti nei confronti degli immigrati stranieri. Questioni di merito #27- Gli operatori sociali sanitari #55- Dal rumore all'esclusione? #6