330 research outputs found
Africa in the Globalisation Era - Poverty and Development in the Third Millennium
No full textAfrica in the Globalisation Era, Poverty and Development in the Third Millennium is the result of two Conferences held in the University of Naples “Federico II” (Department of Political Sciences) on 19th and 20th March. The participation of Professor Riccardo Pelizzo, representing Abel Kinyondo, Senior Researcher at REPOA (Research on Poverty Alleviation) and Senior Lecturerat at University of Dar as Salaam, and Zim Nwokora, a lecturer at Deakin University in Melbourne (Australia), has been very important in order to analyze Africa’s problems. Africa really needs better leaders even though many root-causes of the problems it faces (conflict, instability) are to be found in the past: slave trade, colonialism and other forms of neo-colonialism. Therefore, it is reasonable to ask a question: Considering the necessity of «developing tourism and capitalizing on their natural assets-parks, mountains, oceans, islands and so on», how can the Continent play a major role in the international community
FIGURE DELLA COESISTENZA A CAPO FRASCA
No full textIl litorale sardo è interessato dalla storica presenza di siti d’addestramento militare. Tra questi, oggi permangono Capo San Lorenzo a est, Capo Teulada a sud-ovest, e Capo Frasca a ovest. La loro estensione, rispettivamente 12.700, 7.500 e 1.400 ettari, corrisponde ad ampi tratti a mare; questi ultimi, fortemente compromessi dall’attività bellica, sono attualmente utilizzati in maniera sempre più sporadica. L’interdizione all’accesso e all’uso ha annichilito le forme insediative storiche e le attività produttive primarie, impedendo, inoltre, la fruizione del patrimonio culturale e ambientale. La ricerca progettuale adotta il poligono di Capo Frasca come ‘caso-manifesto’, muovendo dal riconoscimento dalle sue sottese potenzialità, con l’intento di ricomporne le relazioni territoriali e individuare inediti scenari insediativi; volgendosi a un nuovo livello del palinsesto si sperimenta una possibile coesistenza, favorendo la progressiva riappropriazione collettiva dei luoghi
Gabriele Frasca, Prime. Poesie scelte 1977-2007, luca sossella editore, Arte poetica, Roma 2007 [Rezension]
No full textA message passing algorithm for the evaluation of social influence
No full textIn this paper, we define a new measure of node centrality in social networks, the Harmonic Influence Centrality, which emerges naturally in the study of social influence over networks. Next, we introduce a distributed message passing algorithm to compute the Harmonic Influence Centrality of each node: its design is based on an intuitive analogy between social and electrical networks. Although our convergence analysis assumes the networks to have no cycle, the algorithm can be successfully applied on general graphs
Reducing p-Doping of Tin Halide Perovskites by Trivalent Cation Doping
No full textGregori L, Frasca C, Meggiolaro D, et al. Reducing p-Doping of Tin Halide Perovskites by Trivalent Cation Doping. ACS Energy Letters. 2024:3036-3041.We investigate trivalent doping of tin halide perovskites as a means to decrease p-doping and control defect activity. Through density functional theory calculations and experimental characterization, we demonstrate that doping with scandium, lanthanum, and cerium successfully accomplishes Fermi level upshift, reducing background carrier concentration and defect densities, thereby improving material performance. Solar cell fabrication and testing highlight the doping efficacy, with lanthanum delivering increased photocurrent and open circuit voltage compared to control devices, despite being nonoptimized. This research underscores the potential of cation doping in enhancing the functionality of p-doped tin perovskites for advanced optoelectronic applications
Characterization of Neoparamoeba pemaquidensis strains: PCR-RFLP of the internal transcribed spacer region from the amoeba and endosymbiont
No full textNeoparamoeba pemaquidensis continues to be an ongoing problem for commercial finfish aquaculture and has also sporadically been associated with mass mortalities of commercially relevant marine invertebrates. Despite the ubiquity and importance of this amphizoic amoeba, our understanding of the biology as it applies to host range, pathogenicity, tissue tropism, and geographic distribution is severely lacking. This may stem from the inability of current diagnostic tests based on morphology, immunology, and molecular biology to differentiate strains at the subspecies level. In the present study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method based on the internal transcribed spacer (ITS) region that can accurately differentiate amoeba strains of N. pemaquidensis. The investigation focused on the complications of the amoeba ITS microheterogeneity in the development of a subspecies marker and the use of the endosymbiont, Ichthyobodo necator related organism (IRO), ITS region as an alternative marker. The combination of host amoeba and endosymbiont ITS PCR-RFLP analyses was successfully used to correctly identify and characterize an N. pemaquidensis isolate from an outbreak of amoebic gill disease in Atlantic salmon Salmo salar from the west coast of North America (Washington State, USA).Charles G. B. Caraguel, Nathanaëlle Donay, Salvatore Frasca Jr., Charles J. O’Kelly, Richard J. Cawthorn Spencer J. Greenwoo
Apparent remote synchronization of amplitudes: A demodulation and interference effect
No full textA form of "remote synchronization" was recently described, wherein amplitude fluctuations across a ring of non-identical, non-linear electronic oscillators become entrained into spatially-structured patterns. According to linear models and mutual information, synchronization and causality dip at a certain distance, then recover before eventually fading. Here, the underlying mechanism is finally elucidated through novel experiments and simulations. The system non-linearity is found to have a dual role: it supports chaotic dynamics, and it enables the energy exchange between the lower and higher sidebands of a predominant frequency. This frequency acts as carrier signal in an arrangement resembling standard amplitude modulation, wherein the lower sideband and the demodulated baseband signals spectrally overlap. Due to a spatially-dependent phase relationship, at a certain distance near-complete destructive interference occurs between them, causing the observed dip. Methods suitable for detecting non-trivial entrainment, such as transfer entropy and the auxiliary system approach, nevertheless, reveal that synchronization and causality actually decrease with distance monotonically. Remoteness is, therefore, arguably only apparent, as also reflected in the propagation of external perturbations. These results demonstrate a complex mechanism of dynamical interdependence, and exemplify how it can lead to incorrectly inferring synchronization and causality
Message Passing Optimization of Harmonic Influence Centrality
No full textThis paper proposes a new measure of node centrality in social networks, the Harmonic Influence Centrality (HIC), which emerges naturally in the study of social influence over networks. Using an intuitive analogy between social and electrical networks, we introduce a distributed message passing algorithm to compute the HIC of each node. Although its design is based on theoretical results which assume the network to have no cycle, the algorithm can also be successfully applied on general graphs
Atypical transistor-based chaotic oscillators: Design, realization, and diversity
No full textIn this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predominantly anti-persistent monofractal dynamics. Notably, we recurrently found a circuit comprising one resistor, one transistor, two inductors, and one capacitor, which generates a range of attractors depending on the parameter values. We also found a circuit yielding an irregular quantized spike-train resembling some aspects of neural discharge and another one generating a double-scroll attractor, which represent the smallest known transistor-based embodiments of these behaviors. Through three representative examples, we additionally show that diffusive coupling of heterogeneous oscillators of this kind may give rise to complex entrainment, such as lag synchronization with directed information transfer and generalized synchronization. The replicability and reproducibility of the experimental findings are good. Published by AIP Publishing
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