Nuove osservazioni sulla biomeccanica dell’uretere umano

The function of ureter is to transport the urine from the kidney to the urinary bladder. Ureteral peristalsis, the principal motor event that propels urine along the ureter, is the result of coordinated contractions of longitudinal and circular smooth muscle inside the organ wall. Alterations of static and dynamic biomechanical properties of the ureteral wall lead to pathological states compromising regular urine transportation to bladder. Although knowledge on ureteral motility has advanced considerably, the molecular contractile mechanism of ureteral smooth muscle cells is not fully understood. This study provides information about baseline mechanical properties of the entire muscle and the molecular contractile mechanism in human ureter smooth muscle and proposed to investigate if changes in mechanical motor performance in different regions of isolated human ureter are attributable to differences in myosin crossbridge interactions. Classic mechanical, kinetic and energetic parameters derived from the tension-velocity relationship were studied in ureteral smooth muscle strips oriented longitudinally and circularly from abdominal and pelvic human ureter parts. By applying of Huxley’s mathematical model we calculated the total working crossbridge number per mm2 (Ψ), elementary force per single crossbridge (Π0), duration of maximum rate constant of crossbridge attachment 1/f1 and detachment 1/g2 and peak mechanical efficiency (Eff.max). Although no substantial differences exist in structural, biochemical and histological characteristics along the human ureter, abdominal longitudinal smooth muscle strips showed a higher maximum isometric tension, greater shortening, faster shortening velocity and higher maximum peak of work and power output than pelvic ones. Contractile differences were associated with significantly higher crossbridge number per mm2. Abdominal longitudinal muscle strips showed a lower duration of maximum rate constant of crossbridge attachment and detachment and higher peak mechanical efficiency than pelvic ones. Such data suggest that the abdominal human ureter exhibited better mechanical motor performance than pelvic ureter, mainly related to a higher crossbridge number and crossbridge kinetics differences. We believe that our results will be useful to understand better the physiology and physiopathology of ureteral smooth muscle, as well as improving the evaluation of pharmacological and surgical therapies in particular clinical cases

Sustainable entrepreneurship: Comparing the determinants of entrepreneurial self-efficacy and social entrepreneurial self-efficacy

Sustainable entrepreneurship creates value beyond profit. Its role is increasingly important in addressing issues related to environmental challenges. Sustainable entrepreneurs represent a tool to attain the Sustainable Development Goals established by the United Nations that address climate change, social inequality, human rights, and economic development. To solve these challenges, there is a need for high-performing sustainable entrepreneurs. The roles of innovativeness, organizational capabilities, and philanthropic corporate social responsibility (CSR) in the performance of sustainable entrepreneurs are still underexplored. Hence, this study proposes an analysis of the indirect and direct effects of innovativeness on entrepreneurial self-efficacy (ESE) and social entrepreneurial self-efficacy (SESE) and of the mediating role of organizational capabilities and philanthropic CSR. Based on structural equation modeling and importance-performance matrix analysis, the findings from a survey of 116 sustainable entrepreneurs identified a positive relationship between innovativeness and ESE, organizational capabilities, and philanthropic CSR. The indirect relationship mediated by organizational capabilities was found to be positive, while for philanthropic CSR, it was positive for SESE but negative for ESE. Interestingly, it was found that SESE is only positively influenced in indirect relations. This study contributes to the literature on how innovativeness can promote ESE and SESE and the role of organizational capabilities and philanthropic CSR in enhancing performance among sustainable entrepreneurs.info:eu-repo/semantics/publishedVersio

Un Domain Specific Language per la modellazione e l'analisi di giochi

Il model checking consiste in tecniche di verifica formale che consentono di controllare le proprietà comportamentali desiderate in un dato sistema, sulla base di un modello del sistema in questione, attraverso ispezioni sistematiche di tutti i suoi stati. Nelle ultime due decadi queste tecniche si sono sviluppate notevolmente, soprattutto nell'ambito della Computer Science, come metodo per verificare l'assenza di errori. Non è, tuttavia, difficile capire come la costruzione di modelli ad hoc e la verifica formale di proprietà desiderate, sia una tecnica utile in diversi campi del sapere. Il lavoro di sperimentazione alla base di tale tesi tratta, appunto, la definizione di un linguaggio di modellazione da usare nell'ambito del game design per la verifica formale di proprietà di giochi. L'idea nasce da un precedente lavoro di sperimentazione, nel quale i modelli sono stati implementati con lo strumento di model checking PRISM. Il linguaggio di PRISM si è però dimostrato inadeguato per descrivere alcuni aspetti comuni ai giochi. Da questa riflessione è nata l'idea di definire un nuovo linguaggio di alto livello che renda più semplice e rapida la costruzione dei modelli, pur consentendo una successiva compilazione nel linguaggio di input di PRISM

Orazio, Carm. 1.9.9-12

A commentary on Hor. Carm. 1.9.9-12, with particular emphasis on the words stravere (v. 10) and deproeliantis (v. 11), which belong to the lexicon of war

Regional differences of energetics, mechanics, and kinetics of myosin cross-bridge in human ureter smooth muscle

This study provides information about baseline mechanical properties of the entire muscle and the molecular contractile mechanism in human ureter smooth muscle and proposed to investigate if changes in mechanical motor performance in different regions of isolated human ureter are attributable to differences in myosin crossbridge interactions. Classic mechanical, contraction and energetic parameters derived from the tension-velocity relationship were studied in ureteral smooth muscle strips oriented longitudinally and circularly from abdominal and pelvic human ureter parts. By applying of Huxley’s mathematical model we calculated the total working crossbridge number per mm2 (Ψ), elementary force per single crossbridge (Π0), duration of maximum rate constant of crossbridge attachment 1/f1 and detachment 1/g2 and peak mechanical efficiency (Eff.max). Abdominal longitudinal smooth muscle strips exhibited significantly higher maximum isometric tension and faster maximum unloaded shortening velocity compared to pelvic ones. Contractile differences were associated with significantly higher crossbridge number per mm2. Abdominal longitudinal muscle strips showed a lower duration of maximum rate constant of crossbridge attachment and detachment and higher peak mechanical efficiency than pelvic ones. Such data suggest that the abdominal human ureter showed better mechanical motor performance mainly related to a higher crossbridge number and crossbridge kinetics differences. Such results were more evident in the longitudinal rather than in the circular layer

Epidemiology of acute lymphoblastic leukaemia in Sardinia, Italy:Age, sex, and environmental correlates

Using a database of 1974–2003 incident cases of haematological malignancies, we explored the time trend, geographic spread and socio-economic and environmental correlates of ALL incidence in Sardinia, Italy, by sex and age. The age- and sex-standardized (World population) ALL incidence rate was 2.0 per 100,000 (95% CI 1.8 – 2.1) and showed variable trend patterns by sex and age. In the total population, ALL incidence showed an annual per cent change of −1.4% (95% CI -0.59 – -3.34) over the study period, with a knot separating a downward slope in 1974–1996 from an increase in 1996–2003. ALL incidence replicated such pattern in women but not men, whose incidence did not substantially vary over the study period (APC = −2.57%, 95% CI -5.45 – 0.26). Among women, the spatial analysis suggested a clustering of ALL in the southwestern part of the region, whilst only a commune had a high posterior probability of a high ALL incidence among men. Three unrelated communes showed a high posterior probability of ALL at age ≤ 24; only the most populated urban centre showed excess cases at age ≥ 25 years. There was no correlation between the geographic spread of ALL at ages ≤ 24 and ≥ 25 years (p = 0.082). Urban residence was a risk factor for the younger age group. Residences near industrial settlements and in the most populated urban centre were risk factors for subjects aged ≥ 25 years. Our findings suggest age-related differences in ALL aetiology

Chronic Red Bull Consumption during Adolescence: Effect on Mesocortical and Mesolimbic Dopamine Transmission and Cardiovascular System in Adult Rats

Energy drinks are very popular nonalcoholic beverages among adolescents and young adults for their stimulant effects. Our study aimed to investigate the effect of repeated intraoral Red Bull (RB) infusion on dopamine transmission in the nucleus accumbens shell and core and in the medial prefrontal cortex and on cardiac contractility in adult rats exposed to chronic RB consumption. Rats were subjected to 4 weeks of RB voluntary consumption from adolescence to adulthood. Monitoring of in vivo dopamine was carried out by brain microdialysis. In vitro cardiac contractility was studied on biomechanical properties of isolated left-ventricular papillary muscle. The main finding of the study was that, in treated animals, RB increased shell dopamine via a nonadaptive mechanism, a pattern similar to that of drugs of abuse. No changes in isometric and isotonic mechanical parameters were associated with chronic RB consumption. However, a prolonged time to peak tension and half-time of relaxation and a slower peak rate of tension fall were observed in RB-treated rats. It is likely that RB treatment affects left-ventricular papillary muscle contraction. The neurochemical results here obtained can explain the addictive properties of RB, while the cardiovascular investigation findings suggest a hidden papillary contractility impairment