Algorithme rapide de codage conjoint source-canal pour un canal de transmission non-stationnaire

Dans cet article, nous proposons l'algorithme RGSKAε qui permet de construire un dictionnaire qui est optimal dans le cas où il n'y a pas de bruit de transmission et qui est aussi robuste vis-à-vis des erreurs de transmission de tous niveaux. Cet algorithme stochastique ne nécessite aucune connaissance a priori du signal à quantifier et du canal de transmission. Il est indépendant du dictionnaire initial et il est capable de sortir de minima locaux. L'exigence de temps de construction est comparable avec celle de l'algorithme de la k-moyenne (KMA). La mise en oeuvre de l'algorithme RGSKAε est aussi simple que celle de l'algorithme KMA car tous ses paramètres sont fixés, ils ne dépendent pas du type ou de la taille des vecteurs à quantifier. L'algorithme RGSKAε possède des propriétés de convergence très avantageuses: il permet de construire un dictionnaire bien équilibré même si le nombre des vecteurs d'apprentissage est inférieur à la taille du dictionnaire

Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio

Immune response to gut escherichia coli and susceptibility to adjuvant arthritis in the rats

We have investigated the humoral immune response to antigens of predominant gut aerobic bacterial strains (i.e. Escherichia coli) over the course of adjuvant arthritis and oil-induced arthritis in two inbred rat strains: Dark Agouti (DA) and Albino Oxford (AO). We report the presence of antibodies specific to proteins of Escherichia coli in molecular weight range between 20-30 kDa in sera of diseased DA rats, and the absence of these antibodies in the sera of AO rats. In DA rats, CFA and IFA provoked a stronger antibody response to Escherichia coli, especially of the IgG2b antibody class. Intramuscular administration of Escherichia coli preceding the adjuvant arthritis induction had no effect on the development and course of disease, as well as on the activation of T cells in the draining inguinal lymph nodes. Higher serum levels of natural and induced IgA antibodies, combined with a higher CD3(+)CD26(+) cell percentage were found in AO rats. The observed correlation between the serologic response to commensal flora and rats' genetic background as a defining factor for arthritis susceptibility may contribute to the process of creating a favorable (or less favorable) milieu for arthritis development

Specialist palliative and end-of-life care for patients with cancer and SARS-CoV-2 infection: a European perspective

Background: Specialist palliative care team (SPCT) involvement has been shown to improve symptom control and end-of-life care for patients with cancer, but little is known as to how these have been impacted by the COVID-19 pandemic. Here, we report SPCT involvement during the first wave of the pandemic and compare outcomes for patients with cancer who received and did not receive SPCT input from multiple European cancer centres. Methods: From the OnCovid repository (N = 1318), we analysed cancer patients aged ⩾18 diagnosed with COVID-19 between 26 February and 22 June 2020 who had complete specialist palliative care team data (SPCT+ referred; SPCT− not referred). Results: Of 555 eligible patients, 317 were male (57.1%), with a median age of 70 years (IQR 20). At COVID-19 diagnosis, 44.7% were on anti-cancer therapy and 53.3% had ⩾1 co-morbidity. Two hundred and six patients received SPCT input for symptom control (80.1%), psychological support (54.4%) and/or advance care planning (51%). SPCT+ patients had more ‘Do not attempt cardio-pulmonary resuscitation’ orders completed prior to (12.6% versus 3.7%) and during admission (50% versus 22.1%, p < 0.001), with more SPCT+ patients deemed suitable for treatment escalation (50% versus 22.1%, p < 0.001). SPCT involvement was associated with higher discharge rates from hospital for end-of-life care (9.7% versus 0%, p < 0.001). End-of-life anticipatory prescribing was higher in SPCT+ patients, with opioids (96.3% versus 47.1%) and benzodiazepines (82.9% versus 41.2%) being used frequently for symptom control. Conclusion: SPCT referral facilitated symptom control, emergency care and discharge planning, as well as high rates of referral for psychological support than previously reported. Our study highlighted the critical need of SPCTs for patients with cancer during the pandemic and should inform service planning for this population

Expansion of CD4+CD25+ and CD25- T-Bet, GATA-3, Foxp3 and RORγt Cells in Allergic Inflammation, Local Lung Distribution and Chemokine Gene Expression

Allergic asthma is associated with airway eosinophilia, which is regulated by different T-effector cells. T cells express transcription factors T-bet, GATA-3, RORγt and Foxp3, representing Th1, Th2, Th17 and Treg cells respectively. No study has directly determined the relative presence of each of these T cell subsets concomitantly in a model of allergic airway inflammation. In this study we determined the degree of expansion of these T cell subsets, in the lungs of allergen challenged mice. Cell proliferation was determined by incorporation of 5-bromo-2′-deoxyuridine (BrdU) together with 7-aminoactnomycin (7-AAD). The immunohistochemical localisation of T cells in the lung microenvironments was also quantified. Local expression of cytokines, chemokines and receptor genes was measured using real-time RT-PCR array analysis in tissue sections isolated by laser microdissection and pressure catapulting technology. Allergen exposure increased the numbers of T-bet+, GATA-3+, RORγt+ and Foxp3+ cells in CD4+CD25+ and CD4+CD25- T cells, with the greatest expansion of GATA-3+ cells. The majority of CD4+CD25+ T-bet+, GATA-3+, RORγt+ and Foxp3+ cells had incorporated BrdU and underwent proliferation during allergen exposure. Allergen exposure led to the accumulation of T-bet+, GATA-3+ and Foxp3+ cells in peribronchial and alveolar tissue, GATA-3+ and Foxp3+ cells in perivascular tissue, and RORγt+ cells in alveolar tissue. A total of 28 cytokines, chemokines and receptor genes were altered more than 3 fold upon allergen exposure, with expression of half of the genes claimed in all three microenvironments. Our study shows that allergen exposure affects all T effector cells in lung, with a dominant of Th2 cells, but with different local cell distribution, probably due to a distinguished local inflammatory milieu

Time-Dependent COVID-19 Mortality in Patients with Cancer: An Updated Analysis of the OnCovid Registry

Importance: Whether the severity and mortality of COVID-19 in patients with cancer have improved in terms of disease management and capacity is yet to be defined. Objective: To test whether severity and mortality from COVID-19 among patients with cancer have improved during the course of the pandemic. Design, Setting, and Participants: OnCovid is a European registry that collects data on consecutive patients with solid or hematologic cancer and COVID-19. This multicenter case series study included real-world data from 35 institutions across 6 countries (UK, Italy, Spain, France, Belgium, and Germany). This update included patients diagnosed between February 27, 2020, and February, 14, 2021. Inclusion criteria were confirmed diagnosis of SARS-CoV-2 infection and a history of solid or hematologic cancer. Exposures: SARS-CoV-2 infection. Main Outcomes and Measures: Deaths were differentiated at 14 days and 3 months as the 2 landmark end points. Patient characteristics and outcomes were compared by stratifying patients across 5 phases (February to March 2020, April to June 2020, July to September 2020, October to December 2020, and January to February 2021) and across 2 major outbreaks (February to June 2020 and July 2020 to February 2021). Results: At data cutoff, 2795 consecutive patients were included, with 2634 patients eligible for analysis (median [IQR] age, 68 [18-77] years; 52.8% men). Eligible patients demonstrated significant time-dependent improvement in 14-day case-fatality rate (CFR) with estimates of 29.8% (95% CI, 0.26-0.33) for February to March 2020; 20.3% (95% CI, 0.17-0.23) for April to June 2020; 12.5% (95% CI, 0.06-22.90) for July to September 2020; 17.2% (95% CI, 0.15-0.21) for October to December 2020; and 14.5% (95% CI, 0.09-0.21) for January to February 2021 (all P &lt;.001) across the predefined phases. Compared with the second major outbreak, patients diagnosed in the first outbreak were more likely to be 65 years or older (974 of 1626 [60.3%] vs 564 of 1008 [56.1%]; P =.03), have at least 2 comorbidities (793 of 1626 [48.8%] vs 427 of 1008 [42.4%]; P =.001), and have advanced tumors (708 of 1626 [46.4%] vs 536 of 1008 [56.1%]; P &lt;.001). Complications of COVID-19 were more likely to be seen (738 of 1626 [45.4%] vs 342 of 1008 [33.9%]; P &lt;.001) and require hospitalization (969 of 1626 [59.8%] vs 418 of 1008 [42.1%]; P &lt;.001) and anti-COVID-19 therapy (1004 of 1626 [61.7%] vs 501 of 1008 [49.7%]; P &lt;.001) during the first major outbreak. The 14-day CFRs for the first and second major outbreaks were 25.6% (95% CI, 0.23-0.28) vs 16.2% (95% CI, 0.13-0.19; P &lt;.001), respectively. After adjusting for country, sex, age, comorbidities, tumor stage and status, anti-COVID-19 and anticancer therapy, and COVID-19 complications, patients diagnosed in the first outbreak had an increased risk of death at 14 days (hazard ratio [HR], 1.85; 95% CI, 1.47-2.32) and 3 months (HR, 1.28; 95% CI, 1.08-1.51) compared with those diagnosed in the second outbreak. Conclusions and Relevance: The findings of this registry-based study suggest that mortality in patients with cancer diagnosed with COVID-19 has improved in Europe; this improvement may be associated with earlier diagnosis, improved management, and dynamic changes in community transmission over time.

Determinants of enhanced vulnerability to COVID-19 in UK cancer patients: a European Study

Background: Despite high contagiousness and rapid spread, SARS-CoV-2 has led to heterogeneous outcomes across affected nations. Within Europe, the United Kingdom (UK) is the most severely affected country, with a death toll in excess of 100.000 as of January 2021. We aimed to compare the national impact of COVID-19 on the risk of death in UK cancer patients versus those in continental Europe (EU). / Methods: We performed a retrospective analysis of the OnCovid study database, a European registry of cancer patients consecutively diagnosed with COVID-19 in 27 centres from February 27 to September 10, 2020. We analysed case fatality rates and risk of death at 30 days and 6 months stratified by region of origin (UK versus EU). We compared patient characteristics at baseline, including oncological and COVID-19 specific therapy across UK and EU cohorts and evaluated the association of these factors with the risk adverse outcome in multivariable Cox regression models. / Findings: Compared to EU (n=924), UK patients (n=468) were characterised by higher case fatality rates (40.38% versus 26.5%, p<0.0001), higher risk of death at 30 days (hazard ratio, HR 1.64 [95%CI 1.36-1.99]) and 6 months after COVID-19 diagnosis (47.64% versus 33.33%, p<0.0001, HR 1.59 [95%CI 1.33-1.88]). UK patients were more often males, of older age and more co-morbid than EU counterparts (p<0.01). Receipt of anticancer therapy was lower in UK versus EU patients (p<0.001). Despite equal proportions of complicated COVID-19, rates of intensive care admission and use of mechanical ventilation, UK cancer patients were less likely to receive anti-COVID-19 therapies including corticosteroids, anti-virals and interleukin-6 antagonists (p<0.0001). Multivariable analyses adjusted for imbalanced prognostic factors confirmed the UK cohort to be characterised by worse risk of death at 30 days and 6 months, independent of patient’s age, gender, tumour stage and status, number of co-morbidities, COVID-19 severity, receipt of anticancer and anti-COVID-19 therapy. Rates of permanent cessation of anticancer therapy post COVID-19 were similar in UK versus EU. / Interpretation: UK cancer patients have been more severely impacted by the unfolding of the COVID-19 pandemic despite societal risk mitigation factors and rapid deferral of anticancer therapy. The increased frailty of UK cancer patients highlights high-risk groups that should be prioritised for anti-SARS-CoV-2 vaccination. Continued evaluation of long-term outcomes is warranted