Turbulence in Rivers

The study of turbulence has always been a challenge for scientists working on geophysical flows. Turbulent flows are common in nature and have an important role in geophysical disciplines such as river morphology, landscape modeling, atmospheric dynamics and ocean currents. At present, new measurement and observation techniques suitable for fieldwork can be combined with laboratory and theoretical work to advance the understanding of river processes. Nevertheless, despite more than a century of attempts to correctly formalize turbulent flows, much still remains to be done by researchers and engineers working in hydraulics and fluid mechanics. In this contribution we introduce a general framework for the analysis of river turbulence. We revisit some findings and theoretical frameworks and provide a critical analysis of where the study of turbulence is important and how to include detailed information of this in the analysis of fluvial processes. We also provide a perspective of some general aspects that are essential for researchers/ practitioners addressing the subject for the first time. Furthermore, we show some results of interest to scientists and engineers working on river flows

Determining soil hydraulic properties using infiltrometer techniques: An assessment of temporal variability in a long-term experiment under minimum-and no-tillage soil management

Conservation agriculture is increasingly accepted by farmers, but the modeling studies on agro-environmental processes that characterize these agricultural systems require accurate information on the temporal variability of the soil's main physical and hydraulic properties. Therefore, specific investigations carried out in long-term experiments can increase our knowledge on the pros and cons of different measurement techniques. In this work, the simplified falling head (SFH) technique and the Beerkan Estimation of Soil Transfer (BEST) procedure were applied to investigate the temporal variability of some main soil physical and hydraulic properties, including bulk density (BD), field saturated hydraulic conductivity (Kfs), macroporosity (Pmac), air capacity (AC), plant available water capacity (PAWC), and relative field capacity (RFC). For this purpose, a long-term experiment was selected, and the experimental information obtained was used to verify the long-term impact (fifteen years) determined by two alternative forms of soil management, minimum tillage (MT) and no tillage (NT), for the cultivation of durum wheat. The main results of the comparison between MT and NT showed: (i) A comparable temporal variability in Kfs values when SFH was considered, given that in 75% of considered cases, the same result (i.e., significant or not significant) was obtained; (ii) a comparable temporal variability in Kfs values under MT (but not under NT) when both SFH and BEST were used, as a result of a possible Kfs, SFH overestimation under NT; (iii) differences in Kfs estimations by a factor of 6 or 7 (Kfs, SFH > Kfs, BEST) when comparable soil conditions (moisture and soil density) were considered; (iv) a comparable temporal variability when other soil indicators (BD, Pmac, AC, PAWC, and RFC) were simultaneously considered. After about fifteen years of field experiments characterized by continuous soil management and conducted with the methodological rigor typical of experimental farms, the SFH-and BEST-derived experimental information showed a substantial equivalence between MT and NT for the fine-textured soil investigated

LA VALORIZZAZIONE DELLA BIOMASSA ATTRAVERSO IL RICICLAGGIO DEI RIFIUTI DELLA FILIERA OLIVICOLO OLEARIA

IL PRESENTE LAVORO DEFINISCE STRATEGIE PER LA VALORIZZAZIONE DELLA BIOMASSA ATTRAVERSO IL RICICLAGGIO DEI RIFIUTI DELLA FILIERA OLIVICOLO OLEARIA

Can COVID-19 pandemic surveillance reduce nosocomial urinary infections in urologic surgery?

Introduction: Since COVID-19 pandemic spread, strict preventive measures were adopted to reduce the risk of transmission. Antiseptic dispensers for hand hygiene were diffusely available for patients and hospital staff. To investigate the prophylactic role played by the strict antiseptic rules adopted during pandemic, the rates of nosocomial urinary infections in 2019 and 2020 were compared. Materials and methods: Patients’ clinical pre-operative characteristics, symptoms, fever, and laboratory data were recorded pre- and post-operatively. Urological surgery was classified in five categories: 1. major surgery 2. upper urinary tract endoscopy, 3. lower urinary tract endoscopy, 4. minor surgery, and 5. Nephrostomy and ureteral stenting. Clavien-Dindo complication score was used. Statistical analysis was performed with R 3.4.2 software. Results: Out of 495 patients, 383 (57.1%) underwent surgical intervention in pre-pandemic March–May 2019 period and 212 (42.9%) in the same pandemic 2020 interval. Preoperatively, 40 (14.1%) and 11 (5.2%) and 77 (27.3%) and 37 (17.5%) patients had fever (p < 0.003) and leukocytosis (p < 0.02), in 2019 and 2020 respectively. Urine culture was positive in 29 (10.2%) and 13 (6.2%) patients respectively (p = 0.22). Post-operatively, 54 (19.1%) and 22 (10.4%) patients and 17 (6.1%) and 2 (0.6%) patients showed fever (p < 0.003) and positive urineculture (p < 0.03), in 2019 and 2020 respectively. Discussion and conclusion: Preoperative and post-operative clinical and laboratory signs of nosocomial urinary infection showed a statistically significant lower incidence during the pandemic period in 2020. This observation could be ascribed to the strong preventive measures, to the medical staff high adherence to hygiene and the diffuse availability of hand sanitizers

Atrial fibrillation and cognitive disorders: An overview on possible correlation

Atrial Fibrillation is the most common cardiac arrhythmia affecting people of all ages, principally the elderly. Cognitive decline and dementia are also prevalent diseases in elderly. The scientific community always showed interest in the possible association between these two pathological entities, both implicating social and economic burden. This has been confirmed by several longitudinal population-based studies. Some studies also revealed that the association between atrial fibrillation and dementia may be not related to history of stroke. Therefore, other pathophysiological mechanisms are likely implicated, so far unclear or undefined. The aim of the present review is to analyse the possible mechanisms underlying the frequent association between atrial fibrillation and cognitive impairment

Confronto tra differenti metodologie di valutazione della qualit\ue0 fisica del suolo in un\u2019area a pascolo e bosco della Sicilia

Il concetto di qualit\ue0 fisica del suolo (SPQ, Soil Physical Quality) viene ormai largamente utilizzato, soprattutto in ambito agricolo. Un suolo agricolo di buona qualit\ue0 fisica possiede caratteristiche strutturali favorevoli sia all\u2019ancoraggio della coltura sia allo sviluppo dell\u2019apparato radicale della pianta nonch\ue9 un\u2019adeguata ripartizione tra pori di diverse dimensioni, in modo da favorire simultaneamente l\u2019areazione e la ritenzione idrica nel mezzo poroso. Per la valutazione della SPQ sono determinanti le misure di ritenzione idrica del suolo, che possono essere analizzate con diverse metodologie. Alcune indagini recenti segnalano tuttavia che la scelta della metodologia di analisi delle misure pu\uf2 influenzare il giudizio finale sulla SPQ. E\u2019 necessario approfondire la suddetta problematica nell\u2019intento di irrobustire, in prospettiva, la valutazione della SPQ. Il concetto di SPQ inizia a essere applicato sempre pi\uf9 frequentemente anche in aree non agricole e, in particolare, in aree forestali e a pascolo, assumendo che gli indicatori e i loro valori ottimali usati in ambito agricolo siano trasferibili a queste forme di copertura del suolo. La fondatezza di questa scelta necessita ancora, per\uf2, di supporti ulteriori. L\u2019obiettivo dell\u2019indagine \ue8 stato quello di porre a confronto diverse metodologie di valutazione della SPQ sulla base delle misure di ritenzione idrica in una zona caratterizzata dalla presenza di un\u2019area a pascolo e di una a bosco diversificata in relazione al tempo trascorso dall\u2019ultimo taglio di ceduazione (1, 6-7, 20 e 40 anni). Le metodologie poste a confronto fanno ricorso a indici capacitivi, all\u2019indice S di Dexter e ai parametri di posizione e forma della funzione di distribuzione del volume dei pori. L\u2019indagine ha evidenziato un legame tra le metodologie poste a confronto ma ha anche portato a riconoscere una maggiore adeguatezza della metodologia basata sugli indici capacitivi a descrivere la SPQ di suoli a ridotto impatto antropico. Inoltre, suoli agricoli e suoli forestali di buona qualit\ue0 fisica mostrano similitudini in termini di acqua disponibile per la pianta ma il suolo forestale risulta maggiormente areato di quello agricolo. Un suolo forestale a basso impatto antropico, sottoposto cio\ue8 al taglio molto tempo prima del campionamento (20-40 anni) manifesta caratteristiche di qualit\ue0 fisica migliori di un suolo forestale soggetto ad azioni di disturbo pi\uf9 recenti. Il suolo a pascolo appare qualitativamente pi\uf9 scadente di un buon suolo forestale. Infine, il rilievo di significativi legami statistici tra alcuni indicatori capacitivi induce a ritenere che, in generale, la metodologia di valutazione della SPQ possa essere convenientemente semplificata, a vantaggio di una pi\uf9 agevole interpretazione delle misure. In conclusione, l\u2019indagine ha confermato che il concetto di SPQ pu\uf2 essere applicato anche in ambiti non agricoli e ha contribuito alla definizione di valori ottimali degli indicatori capacitivi in un ambito tuttora poco esplorato nella letteratura scientifica internazionale