1,188 research outputs found
The Italian populations of Viola pumila Chaix. Their ecological and genetic characterization for an integrated conservation strategy.
No full textThe Italian populations of Viola pumila Chaix. Their ecological and genetic characterization for an integrated conservation strategy
Buldrini F.1, Dallai D.1, Conte L.2, Del Prete C.1, Ferrari C.2
1 Dep. of Biology, University of Modena and Reggio Emilia
2 Dep. of Experimental Evolutionary Biology, University of Bologna
Viola pumila Chaix is an Eurasian species linked to large alluvial grasslands. Ecology and conservation problems of its Central European populations have been studied by Hölzel (2003), Eckstein & al. (2004, 2006, 2009) and Danihelka & al. (2009). In Italy, it grows only in 4 Po valley sites, in grasslands and fresh meadows regularly mown, along ditches and cultivated fields. These populations are peripheral with respect to the European distribution of the species. They contain a very low number of individuals in each site (max. 46) and are very distant and strictly isolated from the nearest populations of Central Europe. According to IUCN (2001), this species is critically endangered in Italy (Buldrini & Dallai, in press).
Since the best conservation strategy for endangered species implies a detailed knowledge of habitat requirements as well as of its genetic diversity, an ecological characterization of the 4 sites is in progress, by Ellenberg’s Indexes modified by Pignatti & al. (2005). Moreover, the genetic diversity of the Italian populations of the species will be evaluated through ISSR markers: semi-arbitrary anchored primers designed from tandem repeat motifs of microsatellites will be used to estimate the level and the distribution of genetic diversity and to provide suggestions for effective conservation programs.
A comparison between Italian populations and Central European ones will performed in the next stage of the research.
Eckstein R.L., Danihelka J., Hölzel N., Otte A. (2004), Acta Oecol. 25: 83–91
Eckstein R.L., Hölzel N., Danihelka J. (2006), Perspect. Pl. Ecol. Evol. Syst. 8: 45-66
Eckstein R.L., Danihelka J., Otte A. (2009), Biologia 64/1: 69-80
Danihelka J., Niklfeld H., Šípošová H. (2009), Preslia 81: 151-171
Hölzel N. (2003), Folia Geobot. 38: 281-298
Pignatti S., Menegoni P., Pietrosanti S. (2005), Braun-Blanquetia 39: 1-9
Complete subcutaneous rupture of the patellar tendon: Epidemiological and treatment problems in athletes
No full textE. Verni, F. Catani, R. Beluzzi, G. Del Prete, L. Prosperi, and R. Buda: Complete subcutaneous rupture of the patellar tendon: epidemiological and treatment problems in athletes. J. Sports Traumatol. rel. res. 19: 38, 1997. An account is given of 14 cases of patellar tendon rupture observed in 10 years with a minimum follow-up of 18 months. All athletes were treated with the same surgical technique. In addition to providing temporary protection for the tendon suture, cerclage is a sound means of securing the correct position of the patella. The results show that resumption of sport is a more selective criterion than modem clinical and instrumental investigations. The common epidemiological denominator was eccentric pliometric power training. In the absence of controlled scientific data concerning this form of functional overuse, careful selection and periodic monitoring is required of athletes whose explosive force is to be increased through previous stretching of a muscle
Chemokines as relay signals in human dendritic cell migration: Serum amyloid A kicks off chemotaxis.
No full textCell migration is a response highly conserved in evolution. Chemotactic factors secreted in injured and inflamed tissues generate a concentration-based, chemotactic gradient that directs leukocytes from the blood compartment into tissue. In this issue of the European Journal of Immunology, Gouwy et al. [Eur. J. Immunol. 2015. 45: 101-112] show that the SAA1α isoform of serum amyloid A (SAA), which is an acute phase protein upregulated in inflammation and shown to chemoattract some leukocyte subsets, is also able to chemoattract monocyte-derived immature dendritic cells (DCs). The authors also show that the chemotactic activity of SAA1α for monocytes and DCs is indirectly mediated by rapid chemokine induction, providing evidence that proposes a new level of regulation of leukocyte migration
Sheet metal forming processes: Development of an innovative methodology for the integration of the metal forming and structural analysis
No full textSheet metal forming is essential in automotive and aerospace industries, where accurate simulations are crucial for optimizing
material deformation and tool design. Finite Element Analysis (FEA) is a key tool for predicting stresses, strains, and material
fow in these processes. Recent advancements in artifcial intelligence (AI) and machine learning have further enhanced these
simulations, improving toolpath planning and overall process efciency Appl Mech 1:97-110, 2020, ASME J Manuf Sci Eng
144(2):021012, 2021. A critical aspect of sheet metal forming is the development of forming tools, which must withstand
high forces and ensure precision. Traditionally, tool design has relied on a trial-and-error approach, heavily dependent on
manufacturer expertise. This paper introduces an innovative methodology that integrates sheet metal forming simulations
with the structural analysis of forming tools, facilitated by a specialized connector. The connector enables integrated analysis
of the forming process and tool structural behaviour, providing feedback on tool performance under operational loads. The
output of the forming simulation (contact pressures between workpiece and tools) feeds the structural model. Additionally, the
methodology incorporates AI-driven what-if analysis to streamline decision-making in the early design stages. This modular
solution is designed to integrate with a Digital Twin framework, ofering continuous optimization. The proposed methodology enhances manufacturing efciency by reducing simulation time and improving tool structural behaviour predictions,
enabling faster, more accurate tool development and ultimately minimizing trial-and-error in tool design
The challenging meet between human and artificial knowledge. A systems-based view of its influences on firms-customers interaction
No full textDesign: This paper contributes to the discussion about the firms’ approach to artificial intelligence (AI) in frontline interactions under the conceptual umbrella provided by Knowledge Management studies (KM).
Purpose: This paper recalls the attention on a key challenge for customer relationship management (CRM) related to the role of human agents in the management of the ‘switch point’ (SP) for ensuring the effectiveness and efficiency in a customer-machine conversation.
Findings: This paper provides a theoretical model for clarifying the role of human intelligence (HI) in AI-based frontline interactions by highlighting the relevance of the actors’ subjectivity in the dynamics and perceptions of customer-machine conversations.
Originality: An AI-HI complementarity matrix is proposed in spite of the still dominant replacement view
Descartes nel materialismo del tardo Settecento. Encyclopédie, Diderot, d'Holbach, Helvétius, Naigeon
No full textA partire dalla metà del Settecento, secondo quanto riferisce l’articolo «Cartésianisme» dell’abbé J. Pestré e di J. Le Rond D’Alembert, apparso nel volume II dell’Encyclopédie (1752), la filosofia naturale di Cartesio – la cosmologia, in primo luogo – è ritenuta essere un documento del recente passato filosofico, interessante dal punto di vista del «metodo, che appariva accessibile a tutti», ma già caduco sul piano strettamente scientifico. Nel Discorso preliminare dell’Encyclopédie (1751), d’altronde, lo stesso D’Alembert aveva reso omaggio alla figura intellettuale di Cartesio, riconoscendogli il merito «metodico» di aver spezzato «il giogo dei pregiudizi» proprio della «scolastica», pur essendo caduto egli stesso in errore. Quest’attitudine ambigua, di elogio, da una parte, per i meriti antiscolastici o antidogmatici e, dall’altra, di critica nel dettaglio per l’inefficacia scientifica, caratterizza in buona parte anche il giudizio espresso dai materialisti della côterie d’Holbach, da Diderot in prima istanza, il più vicino alle concezioni atee della natura proprie del barone. L’Encyclopédie – per la parte scientifica e matematica – è una delle fonti d’informazione più frequentate dai materialisti del tardo Settecento. La natura-macchina cartesiana, come affermò Pestré, peccava di semplicità in quanto metafora esplicativa. Il suo limite consisteva non tanto nell’assumere la «macchina» come modello – che rimarrà valido, sotto altra forma, anche nella prospettiva materialistica –, quanto nel concepire la materia, nella natura, come pura estensione, nel non prendere in considerazione, nella macchina naturale stessa, l’azione di forze chimiche, principi d’azione ed energie vitali che la muovono dall’interno, la percorrono e le conferiscono un aspetto assai più complesso da intendere che attraverso i semplici «principi meccanici» d’inerzia e di moto uniforme.
La dinamicità contro l’inerzia, l’eterogeneità contro l’uniformità, la chimica contro la fisica-meccanica: questi i tratti caratterizzanti della teoria della materia degli holbachiani, costantemente opposti, in modo critico, alla cosmologia e alla filosofia della natura di Descartes.
Nonostante i ripetuti tentativi di mostrarne i presunti plagi, il pensiero di Descartes apparve fin dall'inizio come un punto di non ritorno nella storia della filosofia e un passaggio obbligato per ogni discorso sulla modernità. Il paradigma cartesiano ha però generato immagini filosofiche divergenti e talvolta ingannevoli rispetto all'originario pensiero di Descartes, nonché interpretazioni storiografiche rivelatesi miraggi rispetto al contenuto dei testi nei quali è stata tramandata la filosofia cartesiana. È una situazione che dura ancora oggi ed è frutto della vitalità di una filosofia tuttora al centro delle discussioni contemporanee. Con questo volume il Gruppo di ricerche sul cartesianismo della «Sapienza» si propone di indagare alcuni di questi diversi "cartesianismi" per mostrare attraverso quali mediazioni e con quali conseguenze Ia filosofia cartesiana sia stata percepita, assimilata, rifiutata e trasformata nei corso degli ultimi quattro secoli, e quali relazioni queste discussioni filosofiche abbiano avuto con la ricerca storiografica su temi,autori e testi riconducibili a quella tradizione
Laser defocusing effect on the microstructure and defects of 17-4ph parts additively manufactured by slm at a low energy input
No full textIn this paper, the microstructure, defects, hardness, and tensile strength of the 17-4PH specimens manufactured additively using the selective laser melting (SLM) technique were studied. The analyzed parts (10 mm size cubic specimens and tensile specimens) were manufactured with different defocus parameter values (−1, 0, +1 mm) in order to evaluate this effect with a low power laser (38 W). The study was carried out on three different sections of each cubic specimen, one perpendicular to the laser beam or SLM manufacturing direction (transversal section), and another two parallel to the laser beam direction (longitudinal sections). The specimens microstructures were analyzed with an X-ray diffraction technique, as well as optical, scanning electron, and transmission electron microscopes. Image J software was used to characterize the defects and phase ratio. In addition, hardness and tensile tests were performed according to the corresponding standards. The results show that the amount of austenitic phase and the average grain size varied with defocusing. The percentage of defective area was less than 0.25%. The analyzed defocus distance did not affect the number and average size of the defects. Adjusting the defocusing SLM parameter is important for manufacturing parts with good mechanical properties
Commentaire d'Antonella Del Prete à la note critique de J.-P. Cavaillé
No full textLa longue discussion bibliographique de Jean-Pierre Cavaillé s’impose dans le panorama des études sur le libertinage et le xviie siècle à deux égards : pour sa tentative de faire une histoire du libertinage « à part entière », sans se cantonner à un domaine spécifique (historique, littéraire ou philosophique) — attitude historiographique qui serait d’ailleurs souhaitable dans d’autres cas aussi, puisque le « spécialisme » exclusif est loin d’être une habitude du Grand Siècle — ; pour sa verve..
On the reliability and repeatability of surface electromyography factorization by muscle synergies in daily life activities
No full textMuscle synergy theory is a new appealing approach for different research fields. This study is aimed at evaluating the robustness of EMG reconstruction via muscle synergies and the repeatability of muscle synergy parameters as potential neurophysiological indices. Eight healthy subjects performed walking, stepping, running, and ascending and descending stairs' trials for five repetitions in three sessions. Twelve muscles of the dominant leg were analyzed. The “nonnegative matrix factorization” and “variability account for” were used to extract muscle synergies and to assess EMG goodness reconstruction, respectively. Intraclass correlation was used to quantify methodology reliability. Cosine similarity and coefficient of determination assessed the repeatability of the muscle synergy vectors and the temporal activity patterns, respectively. A 4-synergy model was selected for EMG signal factorization. Intraclass correlation was excellent for the overall reconstruction, while it ranged from fair to excellent for single muscles. The EMG reconstruction was found repeatable across sessions and subjects. Considering the selection of neurophysiological indices, the number of synergies was not repeatable neither within nor between subjects. Conversely, the cosine similarity and coefficient of determination values allow considering the muscle synergy vectors and the temporal activity patterns as potential neurophysiological indices due to their similarity both within and between subjects. More specifically, some synergies in the 4-synergy model reveal themselves as more repeatable than others, suggesting focusing on them when seeking at the neurophysiological index identification
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