Macroscopic effects of the spectral structure in turbulent flows

Two aspects of turbulent flows have been the subject of extensive, split research efforts: macroscopic properties, such as the frictional drag experienced by a flow past a wall, and the turbulent spectrum. The turbulent spectrum may be said to represent the fabric of a turbulent state; in practice it is a power law of exponent \alpha (the "spectral exponent") that gives the revolving velocity of a turbulent fluctuation (or "eddy") of size s as a function of s. The link, if any, between macroscopic properties and the turbulent spectrum remains missing. Might it be found by contrasting the frictional drag in flows with differing types of spectra? Here we perform unprecedented measurements of the frictional drag in soap-film flows, where the spectral exponent \alpha = 3 and compare the results with the frictional drag in pipe flows, where the spectral exponent \alpha = 5/3. For moderate values of the Reynolds number Re (a measure of the strength of the turbulence), we find that in soap-film flows the frictional drag scales as Re^{-1/2}, whereas in pipe flows the frictional drag scales as Re^{-1/4} . Each of these scalings may be predicted from the attendant value of \alpha by using a new theory, in which the frictional drag is explicitly linked to the turbulent spectrum. Our work indicates that in turbulence, as in continuous phase transitions, macroscopic properties are governed by the spectral structure of the fluctuations.Comment: 6 pages, 3 figure

Application of an Exhausted Fermentation Broth Obtained from Biohydrogen Production in an Apple Orchard: Assessment of Fruit Quality

About 95% of global hydrogen production is made by fossil fuels using different technologies which are all characterized by high energy consumption and high carbon emissions. Alternatively, more sustainable production methods, such as biological fermentation processes, are under study. Dark fermentation, also called acidogenesis, entails the transformation of a great variety of organic substances into a mixture of organic and inorganic products, as well as gases (H-2 and CO2). In this study we tested an exhausted fermentation broth, derived after Clostridium fermentation for H-2 production, as a biostimulant via foliar application in an intensive apple orchard. Two different doses were applied upon dilution of the broth in water (100 mL L-1 and 10 mL L-1), evaluating the main fruit quality parameters (fresh weight, fruit diameter, dry matter, firmness, soluble solid content, color lightness, DA index) in addition to macro- and micro-nutrients and heavy metals concentrations. Chemical characterization of the broth showed a high amount of low-MW polypeptides (Trp-Glu-Lys, Ile-Pro-Ile, Phe-Pro-Lys, His-Pro) and organic acids (formic acid, butyric acid, butanedioic acid); moreover, quantitative analyses of inorganic ions showed no heavy metal detection but high concentrations of nitrogen, phosphorus and potassium, compatible with use in agriculture. The fruit quality parameters showed significantly higher mean fruit weight compared to the untreated trees, as well as higher dry matter. No statistical differences were recorded among the treatments for fruit firmness, diameter and yield. Soluble solids content in both treatments were significantly lower than the controls, whereas the DA index mean values were higher in both treatments compared to the controls, indicating a delay in fruit ripening probably due to the high nitrogen broth concentration. Regarding the chemical analyses of fruits, no particular differences were found among the treatments, except for Fe, which showed a significantly higher amount upon treatment with the lower dose. As concerns leaves, no phytotoxic symptoms were detected in both treatments, making the described exhausted broth a candidate for its use as a plant biostimulant. Additional studies are needed to evaluate the ideal application dose, identify further action targets and implement appropriate strategies to concentrate the biostimulant active compounds

A reanalysis of the luminosities of clusters of galaxies in the EMSS sample with 0.3 < z < 0.6

The X-ray luminosities of the Einstein Extended Medium Sensitivity Survey (EMSS) clusters of galaxies with redshifts 0.3<z<0.6 are remeasured using ROSAT PSPC data. It is found that the new luminosities are on average 1.18 +/- 0.08 times higher than previously measured but that this ratio depends strongly on the X-ray core radii we measure. For the clusters with small core radii, in general we confirm the EMSS luminosities, but for clusters with core radii >250 kpc (the constant value assumed in the EMSS), the new luminosities are 2.2 +/- 0.15 times the previous measurements. The X-ray luminosity function (XLF) at 0.3<z<0.6 is recalculated and is found to be consistent with the local XLF. The constraints on the updated properties of the 0.3<z<0.6 EMSS sample, including a comparison with the number of clusters predicted from local XLFs, indicate that the space density of luminous, massive clusters has either not evolved or has increased by a small factor ~2 since z=0.4. The implications of this result are discussed in terms of constraints on the cosmological parameter Omega_0.Comment: 12 pages, 7 figures. Accepted for publication in MNRA

Risk stratification for arrhythmic events in patients with nonischemic dilated cardiomyopathy and nonsustained ventricular tachycardia: Role of programmed ventricular stimulation and the signal-averaged electrocardiogram

AbstractObjectives. This study investigated prediction of arrhythmic events by the signal-averaged electrocardiogram (ECG) and programmed stimulation in patients with nonischemic dilated cardiomyopathy.Background. Risk stratification in patients with nonischemic dilated cardiomyopathy remains controversial.Methods. Eighty patients with nonischemic dilated cardiomyopathy and spontaneous nonsustained ventricular tachycardia underwent signal-averaged electrocardiography (both time-domain and spectral turbulence analysis) and programmed stimulation. All patients were followed up for a mean of 22 ± 26 months.Results. Sustained monomorphic ventricular tachycardia was induced in 10 patients (13%), who all received amiodarone. The remaining 70 patients were followed up without antiarrhythmic therapy. Of the 80 patients, 15% had abnormal findings on the time-domain signal-averaged ECG, and 39% had abnormal findings on spectral turbulence analysis. Time-domain signal-averaged electrocardiography had a better predictive accuracy for induced ventricular tachycardia than spectral turbulence analysis (88% vs. 66%, p < 0.01). During follow-up, there were 9 arrhythmic events (5 sudden deaths, 4 spontaneous ventricular tachycardia/fibrillation) and 10 nonsudden cardiac deaths. Cox regression analysis showed that no variables predicted arrhythmic events or total cardiac deaths. The 2-year actuarial survival free of arrhythmic events was similar in patients with or without abnormal findings on the signal-averaged ECG or induced ventricular tachycardia.Conclusions. In patients with nonischemic dilated cardiomyopathy, 1) there is a strong correlation between abnormal findings on the time-domain signal-averaged ECG and induced ventricular tachycardia, but both findings are uncommon; and 2) normal findings on the signal-averaged ECG, as well as failure to induce ventricular tachycardia, do not imply a benign outcome

OP0086 GENDER INFLUENCE ON CLINICAL MANIFESTATIONS, DEPRESSIVE SYMPTOMS AND BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) SERUM LEVELS IN PATIENTS AFFECTED BY FIBROMYALGIA

Background:Fibromyalgia (FM) is a common rheumatic disease characterized by chronic widespread pain, sleep and mood disorders. A higher prevalence of FM in women compared with men is well known, although the specific differences in clinical manifestations related to gender are still poorly defined. Brain-Derived Neurotrophic Factor (BDNF) is an endogenous growth factor that gained attention for its potential as biomarker of several diseases, including FM and depression.Objectives:The aims of this study were to investigate gender-related difference among males and females affected by FM in clinical manifestations, depressive features and BDNF serum level, evaluating also the diagnostic potential of the latter.Methods:We consecutively enrolled adult patients affected by FM (ACR 2016) referring to our out-patient clinic. Each subject underwent clinical and answered to questionnaires for the severity of FM symptoms (Revised Fibromyalgia Impact Questionnaire, R-FIQ) and depressive symptoms (Beck Depression Inventory-II, BDI-II). We collected blood samples from a subgroup of patients of both sexes, matched for age, for BDNF serum level dosage through ELISA. BDNF levels were assessed also in a control group, matched for sex and age.Results:The cohort was composed by 201 FM patients (172 F, 29 M), mean age 49.13. Females showed higher values of R-FIQ total score (p=0,0005) as well the specific items of the R-FIQ for pain (p=0,013), fatigue (p=0,014), memory problems (p=0,007), tenderness to touch (p<0,0001), balance problems (p<0,0001) and sensitivity to environmental stimuli (p=0,012) when compared with males (fig. 1). There was no difference in BDI-II between males and females, but notably male patients reported a significantly higher frequency of coexisting depressive disorder (p=0,038) (fig. 2). Serum BDNF levels were evaluated in 40 FM patients and 40 healthy controls (HC) (F:M 1:1). BDNF levels were significantly lower in FM patients compared with HC (p<0,0001). Among FM patients, BDNF levels were lower in males compared with females (p<0,0001) (fig.3). BDNF did not correlate with any clinical and clinimetric parameter. BDNF showed a good diagnostic performance (AUC=0,89, CI95%=0,82-0,9630, p<0,0001) (fig. 4). At a cut-off value <6,47 ng/dl, BDNF showed a specificity of 75% and a sensibility of 92,31%,(CI 95%=79,68-97.35) for FM identification (LR=3,692).Conclusion:FM clinical manifestations are strongly dependant from gender. While females present a more severe disease and a higher burden of symptoms, mood disorders tend to be a major characteristic of males with FM. Reduced BDNF serum levels have been reported as typical of depressive disorders. Our findings of lower BDNF levels in male FM patients compared to females support this hypothesis. BDNF have potential as biomarker of the disease and should be validated in larger cohorts.References:[1]Sarzi-Puttini et al. Nature Reviews 2020[2]Colucci-D'Amato et al. Int J Molecular Sciences 2020[3]Nugraha et al. Rheumatol Int 2012[4]Schmitt et al. Ann Med 2016[5]Melchior et al. Neuroscience 2016[6]Stefani et al. Neuroscience Letters 2012Disclosure of Interests:None declare

Dietary habits and nutrition in rheumatoid arthritis: can diet influence disease development and clinical manifestations?

Rheumatoid arthritis (RA) is a systemic, autoimmune disease characterized by joint involvement, with progressive cartilage and bone destruction. Genetic and environmental factors determine RA susceptibility. In recent years, an increasing number of studies suggested that diet has a central role in disease risk and progression. Several nutrients, such as polyunsaturated fatty acids, present anti-inflammatory and antioxidant properties, featuring a protective role for RA development, while others such as red meat and salt have a harmful effect. Gut microbiota alteration and body composition modifications are indirect mechanisms of how diet influences RA onset and progression. Possible protective effects of some dietary patterns and supplements, such as the Mediterranean Diet (MD), vitamin D and probiotics, could be a possible future adjunctive therapy to standard RA treatment. Therefore, a healthy lifestyle and nutrition have to be encouraged in patients with RA

The fate of bacteria in urban wastewater-irrigated peach tree: a seasonal evaluation from soil to canopy

Irrigation with wastewater can be a solution to preserve and mitigate freshwater demand, in particular during drought periods. Unfortunately, wastewater, although being treated at different levels, could be a carrier of human pathogens (e.g., E. coli) and potentially contaminate crops for human consumptions.This study investigated the seasonal microbiological concentrations, on soil, shoot and fruit tissues of potted peach trees, following two irrigation treatments: freshwater (FW) and secondary urban wastewater without the final disinfection treatment (SW). E. coli was only detected in SW irrigated soil, whereas total coliforms (TC) and total bacteria counts (TBC) were similar in both treatments throughout the season. EndophyticE. coli, Salmonella spp. and TC were not detected in shoot and fruit, but a higher presence of total bacteria (TBC) was observed in SW-irrigated tree compared to FWirrigated tree. In particular, SW shoots had a higher load compared to fruits, thus showing a potential effect of leaf transpiration, that promoted the transfer of water-borne bacteria from soil to the epigeal part (shoot). The adoption of low-quality SW (even above the microbiological limits of the European Regulation 2020/741 for wastewater re-use in agriculture), when a drip irrigation method is applied, could be a valid alternative to save fresh water without compromising fruit safety

La enseñanza del inglés en la universidad en un contexto de virtualidad. Una propuesta de curso virtual para la Licenciatura en Enfermería en la Universidad Nacional de San Luis

La irrupción inesperada del coronavirus SARS-CoV-2 en 2020 generó una pandemia a nivel mundial, perjudicando la educación y ocasionando cambios en todos los niveles, particularmente en la modalidad de enseñanza, en la metodología de trabajo y en los modos de relación. En el nivel universitario, docentes y estudiantes debieron asimilar nuevos modos de enseñar y aprender, adquirir nuevas herramientas de enseñanza y aprendizaje, y familiarizarse y acostumbrarse a nuevos modos de relacionarse de manera virtual, a fin de garantizar el derecho a la educación superior. Este trabajo tiene como objetivo informar el desarrollo de un nuevo curso totalmente virtual para el dictado de Inglés para la Licenciatura en Enfermería de la Facultad de Ciencias de la Salud de la Universidad Nacional de San Luis (UNSL), teniendo en cuenta la experiencia de enseñanza de 2020 y el proceso llevado a cabo para el diseño de esta propuesta. A partir de algunas dimensiones problemáticas identificadas, y tomando como fundamentos teóricos los conceptos de educación y virtualidad, aula virtual, curaduría de contenidos, clase virtual y evaluación en virtualidad, las docentes se propusieron diseñar un nuevo curso optimizando las herramientas tecnológicas disponibles para que sean funcionales a los objetivos del curso y promuevan el pensamiento crítico, la reflexión, la autonomía, el crecimiento personal y profesional de estudiantes y docentes. La implementación de esta propuesta podría generar una mejora significativa en el dictado de la asignatura en un contexto de virtualidad como el actual, siendo posible adoptar los aportes de este trabajo para otras asignaturas de lengua extranjera de la UNSL