Symmetries of Helmholtz forms and globally variational dynamical forms

Invariance properties of classes in the variational sequence suggested to Krupka et al. the idea that there should exist a close correspondence between the notions of variationality of a differential form and invariance of its exterior derivative. It was shown by them that the invariance of a closed Helmholtz form of a dynamical form is equivalent with local variationality of the Lie derivative of the dynamical form, so that the latter is locally the Euler--Lagrange form of a Lagrangian. We show that the corresponding local system of Euler--Lagrange forms is variationally equivalent to a global Euler--Lagrange form.Comment: Presented at QTS7 - Quantum Theory and Symmetries VII, Prague 7-13/08/201

Different roles for the acyl chain and the amine leaving group in the substrate selectivity of N-Acylethanolamine acid amidase

N-acylethanolamine acid amidase (NAAA) is an N-terminal nucleophile (Ntn) hydrolase that catalyses the intracellular deactivation of the endogenous analgesic and anti-inflammatory agent palmitoylethanolamide (PEA). NAAA inhibitors counteract this process and exert marked therapeutic effects in animal models of pain, inflammation and neurodegeneration. While it is known that NAAA preferentially hydrolyses saturated fatty acid ethanolamides (FAEs), a detailed profile of the relationship between catalytic efficiency and fatty acid-chain length is still lacking. In this report, we combined enzymatic and molecular modelling approaches to determine the effects of acyl chain and polar head modifications on substrate recognition and hydrolysis by NAAA. The results show that, in both saturated and monounsaturated FAEs, the catalytic efficiency is strictly dependent upon fatty acyl chain length, whereas there is a wider tolerance for modifications of the polar heads. This relationship reflects the relative stability of enzyme-substrate complexes in molecular dynamics simulations

The Lie derivative of spinor fields: theory and applications

Starting from the general concept of a Lie derivative of an arbitrary differentiable map, we develop a systematic theory of Lie differentiation in the framework of reductive G-structures P on a principal bundle Q. It is shown that these structures admit a canonical decomposition of the pull-back vector bundle i_P^*(TQ) = P\times_Q TQ over P. For classical G-structures, i.e. reductive G-subbundles of the linear frame bundle, such a decomposition defines an infinitesimal canonical lift. This lift extends to a prolongation Gamma-structure on P. In this general geometric framework the concept of a Lie derivative of spinor fields is reviewed. On specializing to the case of the Kosmann lift, we recover Kosmann's original definition. We also show that in the case of a reductive G-structure one can introduce a "reductive Lie derivative" with respect to a certain class of generalized infinitesimal automorphisms, and, as an interesting by-product, prove a result due to Bourguignon and Gauduchon in a more general manner. Next, we give a new characterization as well as a generalization of the Killing equation, and propose a geometric reinterpretation of Penrose's Lie derivative of "spinor fields". Finally, we present an important application of the theory of the Lie derivative of spinor fields to the calculus of variations.Comment: 28 pages, 1 figur

Chemical, biochemical and microbiological properties of soils from abandoned and extensively cultivated olive orchards

The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical and microbiological properties in a soil of a Southern olive grove abandoned since 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog® method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities

Evaluation of qualitative and semi-quantitative cut offs for rapid diagnostic lateral flow test in relation to serology for the detection of SARS-CoV-2 antibodies: findings of a prospective study

Background:: There is limited information to compare the qualitative and semi-quantitative performance of rapid diagnostic tests (RDT) and serology for the assessment of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, the objective of the study was (a) to compare the efficacy of SARS-CoV-2 antibody detection between RDT and laboratory serology, trying to identify appropriate semi-quantitative cut-offs for RDT in relation with quantitative serology values and to (b) evaluate diagnostic accuracy of RDT compared to the NAAT gold standard in an unselected adult population. Methods:: SARS-CoV-2 antibodies were simultaneously measured with lateral flow immunochromatographic assays (LFA), the Cellex qSARS-CoV-2 IgG/IgM Rapid Test (by capillary blood), the iFlash-SARS-CoV-2 IgG/IgM chemiluminescent immunoassay (CLIA) (by venous blood) and the nucleic acid amplification test (NAAT) in samples from in- and out-patients with confirmed, suspected and negative diagnosis of coronavirus disease 2019 (COVID-19) attending Udine Hospital (Italy) (March-May 2020). Interpretation of RDT was qualitative (positive/negative) and semi-quantitative based on a chromatographic intensity scale (negative, weak positive, positive). Results:: Overall, 720 paired antibody measures were performed on 858 patients. The qualitative and semiquantitative agreement analysis performed in the whole sample between LFA and CLIA provided a Kendall’s tau of 0.578 (p < 0.001) and of 0.623 (p < 0.001), respectively, for IgM and IgG. In patients with a diagnosis of COVID-19, accordance between LFA and CLIA was maintained as a function of time from the onset of COVID-19 disease and the severity of disease both for qualitative and semi-quantitative assessments. RDT compared to the NAAT gold standard in 858 patients showed 78.5% sensitivity (95% CI 75.1%-81.7%) and 94.1% specificity (95% CI 90.4%-96.8%), with variable accordance depending on the timing from symptom onset. Conclusion:: The RDT used in our study can be a non-invasive and reliable alternative to serological tests and facilitate both qualitative and a semi-quantitative antibody detection in COVID-19

Risk Assessment by Pre-surgical Tractography in Left Hemisphere Low-Grade Gliomas

Background: Tracking the white matter principal tracts is routinely typically included during the pre-surgery planning examinations and has revealed to limit functional resection of low-grade gliomas (LGGs) in eloquent areas. Objective: We examined the integrity of the Superior Longitudinal Fasciculus (SLF) and Inferior Fronto-Occipital Fasciculus (IFOF), both known to be part of the language-related network in patients with LGGs involving the temporo-insular cortex. In a comparative approach, we contrasted the main quantitative fiber tracking values in the tumoral (T) and healthy (H) hemispheres to test whether or not this ratio could discriminate amongst patients with different post-operative outcomes. Methods: Twenty-six patients with LGGs were included. We obtained quantitative fiber tracking values in the tumoral and healthy hemispheres and calculated the ratio (HIFOF\u2013TIFOF)/HIFOF and the ratio (HSLF\u2013TSLF)/HSLF on the number of streamlines. We analyzed how these values varied between patients with and without post-operative neurological outcomes and between patients with different post-operative Engel classes. Results: The ratio for both IFOF and SLF significantly differed between patient with and without post-operative neurological language deficits. No associations were found between white matter structural changes and post-operative seizure outcomes. Conclusions: Calculating the ratio on the number of streamlines and fractional anisotropy between the tumoral and the healthy hemispheres resulted to be a useful approach, which can prove to be useful during the pre-operative planning examination, as it gives a glimpse on the potential clinical outcomes in patients with LGGs involving the left temporo-insular cortex

Antibody response and risk of reinfection over 2 years among the patients with first wave of COVID-19

Objectives: To describe the dynamics and factors related to natural and hybrid humoral response against the SARS-CoV-2 and risk of reinfection among first-wave patients. Methods: A prospective longitudinal study with periodic serological follow-up after acute onset of all recovered patients with SARS-CoV-2 infection cared in Udine Hospital (March–May 2020). Nucleocapsid (N) protein and spike receptor-binding domain (S-RBD) antibody tests were used to distinguish natural and vaccine-induced response. Results: Overall, 153 patients (66 men, mean age 56 years) were followed for a median of 27.3 (interquartile range 26.9–27.8) months. Seroreversion was 98.5% (95% CI: 96.8–99.4) for SARS-CoV-2-N IgM at 1 year and 57.4% (95% CI: 51.5–63.5) for SARS-CoV-2-N IgG at 2 years. Initial serological response (hazard ratio [HR]: 0.99, 95% CI: 0.99–0.99, p 0.002 for IgM and HR: 0.97, 95% CI: 0.97–0.98, p < 0.001 for IgG) and severity of acute infection (HR: 0.62, 95% CI: 0.39–0.96, p 0.033 for IgM and HR: 0.60, 95% CI: 0.37–0.99, p < 0.001 for IgG) were independently associated with persistent SARS-CoV-2-N IgM/IgG response. Older age and smoker status were associated with long-term SARS-CoV-2-N IgM and SARS-CoV-2-N IgG, respectively (HR: 0.75, 95% CI: 0.57–0.98, p 0.038; HR: 1.77, 95% CI: 1.19–2.61, p 0.004 respectively). All patients maintained SARS-CoV-2-S-RBD IgG response at 24-month follow-up. Reinfections occurred in 25 of 153 (16.3%) patients, mostly during the omicron circulation. Reinfection rates did not differ significantly between SARS-CoV-2-N IgG seronegative and seropositive patients (14/89, 15.7% vs. 10/62, 16.1%, p 0.947). Unvaccinated patients had higher risk of reinfection (4/7, 57.1% vs. vaccinated 21/146, 14.4%, p 0.014). Discussion: First-wave patients had durable natural humoral immunity in 40% and anti-S-RBD response in 100% up to 2 years after infection. Natural humoral response alone was not protective against reinfections with omicron SARS-CoV-2 variants, whereas vaccination was effective to reduce the risk of a new infection

Investigating serum and tissue expression identified a cytokine/chemokine signature as a highly effective melanoma marker

The identification of reliable and quantitative melanoma biomarkers may help an early diagnosis and may directly affect melanoma mortality and morbidity. The aim of the present study was to identify effective biomarkers by investigating the expression of 27 cytokines/chemokines in melanoma compared to healthy controls, both in serum and in tissue samples. Serum samples were from 232 patients recruited at the IDI-IRCCS hospital. Expression was quantified by xMAP technology, on 27 cytokines/chemokines, compared to the control sera. RNA expression data of the same 27 molecules were obtained from 511 melanoma-and healthy-tissue samples, from the GENT2 database. Statistical analysis involved a 3-step approach: analysis of the single-molecules by Mann–Whitney analysis; analysis of paired-molecules by Pearson correlation; and profile analysis by the machine learning algorithm Support Vector Machine (SVM). Single-molecule analysis of serum expression identified IL-1b, IL-6, IP-10, PDGF-BB, and RANTES differently expressed in melanoma (p &lt; 0.05). Expression of IL-8, GM-CSF, MCP-1, and TNF-α was found to be significantly correlated with Breslow thickness. Eotaxin and MCP-1 were found differentially expressed in male vs. female patients. Tissue expression analysis identified very effective marker/predictor genes, namely, IL-1Ra, IL-7, MIP-1a, and MIP-1b, with individual AUC values of 0.88, 0.86, 0.93, 0.87, respectively. SVM analysis of the tissue expression data identified the combination of these four molecules as the most effective signature to discriminate melanoma patients (AUC = 0.98). Validation, using the GEPIA2 database on an additional 1019 independent samples, fully confirmed these observations. The present study demonstrates, for the first time, that the IL-1Ra, IL-7, MIP-1a, and MIP-1b gene signature discriminates melanoma from control tissues with extremely high efficacy. We therefore propose this 4-molecule combination as an effective melanoma marker

A Novel Paramyxovirus?

In public databases, we identified sequences reported as human genes expressed in kidney mesangial cells. The similarity of these genes to paramyxovirus matrix, fusion, and phosphoprotein genes suggests that they are derived from a novel paramyxovirus. These genes are sufficiently unique to suggest the existence of a novel paramyxovirus genus