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Direct and Indirect Experimental Methodologies for the Hydro-Acoustic Analysis of Marine Propellers
Get PDFThe present paper reviews two "unconventional" approaches to experimentally address the diagnostics, analysis and solution of hydroacoustic problems in naval engineering. The first approach, based on direct pressure fluctuation measurements combined with detailed flow measurements in the proximity of the noise source, provides a direct estimate of the flow phenomena at the origin of sound generation and emission. The second approach is a relatively recent strategy to investigate the sources of acoustic noise in the aeronautical field and concerns the use of volumetric techniques, such as Tomographic PIV (Elsinga, et al., 2006), in combination with acoustic analogies. The abilities of the two approaches are investigated with reference to the analysis of the noise sources in some test cases consisting of an isolated propeller, a propeller operating in the wake a surface ship, and an open-water propeller-rudder system. Both approaches are shown to enable the physical interpretation of the potential mechanism of noise generation and emission from a naval propeller
Flexible power grip use by capuchin monkeys (Sapajus spp.)
Get PDFGrasping behavior relies on both motor and cognitive skills. The variability of power grip actions in a reaching-for-grasping task has been assessed in capuchins monkeys (N=20). On average, each individual used more than five different grip types, revealing a flexible use of the hand and a preference for the use of the thumb in opposition to the other fingers. No evidence of hemispheric specialization was found, however action planning abilities varied as a function of age and task practice
Violence and Complexity
No full textLike all the phenomena that the human mind is knowledgeable about, the phenomenon of violence should be regarded as a complex macrosystem, where systems of networks and of agents are linked and interact at different interconnected levels. This means that complexity refers both to the phenomenon per se and to the various cognitive and emotional processes through which the human mind should examine and evaluate it. It is clear that the complexity of these processes of examination and evaluation should be a requisite both of scientists and of laypeople. This does not mean that the scientist or the layperson should be knowledgeable about all the components and aspects of the macrosystem in their complex interconnections but that they should think and act on the grounds of their awareness of this complexity. One of the main issues relating to the study of violence is the definition of violence itself. As an exemplar of the difficulty regarding this specific issue, some considerations will draw on data obtained in a previous study on children and adolescents\u27 animal abuse experiences. It is also important to point out that complexity does not only refer to the explorations of the connections between systems taken from different research fields (e.g., neurology, biology, psychology, sociology, etc.). It can also refer, for example, to the theoretical premises of the research and of the questions at stake, to the scope and aims of the research and of these questions, and to the methods used in the investigation. In the same way, it is also important to bear in mind that, rooted in the theoretical premises and in the aims, are also specific views of society and life in general and that these views deeply and unavoidably affect the whole investigation process. It is clear that focusing on complexity also means opposing the fragmentation which usually characterizes the scientific study of violence and the interventions aiming to countervail it. Finally, as complexity theory indicates, through this "holistic" approach, a new conceptualization and understanding of violence could emerge so as to lead to more innovative and effective solutions to the problem of violence
Minority Children\u27s Narratives and the Transformation of Social Categorization
No full textThe paper aims to explore processes of transformation of social categorization as these are expressed in minority children\u27s narratives about their experience of discrimination. I examine two open-ended essays written by children attending elementary schools respectively in Japan and in Italy. Children who try to describe experienced discrimination and external categorization in different cultural and social contexts can use similar strategies leading to the transformation of categories. The paper analyses the means employed in these processes. Ultimately, it discusses how writing practices and essay-readings represent important methods that education might use in order to engage children in self-reflection
How Emotional, Economic and Material Dependency May Produce Poverty for Women
Get PDFDependencies, mainly for women, represent a factor that studies from \u2770s on have detected as originating a greater risk of social exclusion and vulnerability and, ultimately, of poverty. Main dimensions of dependency emerged from literature regard following aspects: 1) economic (income sources); 2) material (non-economic help in the management of the household from family of origin and friends); 3) emotional (need of an external emotional support). This contribution originates from a 2012 research on poverty and social exclusion, conducted in Italy by National Research Council, involving almost 1000 subjects. Three indexes have been built, referring to different dependencies detected by literature: Economic Dependency Index (EDI), Material Dependency Index (MDI) and Emotional Dependency Index (EDI). These indexes, together with other indicators, have been used with the aim of comparing female versus male respondents. Furthermore, women\u27 profiles have been drawn out that are potentially vulnerable to poverty and social exclusion (elderly women, women with precarious jobs and divorcees) more than others
Abstract Knowledge in the Broken-String Problem: Evidence from Nonhuman Primates and Pre-Schoolers
Get PDFThere is still large controversy about whether abstract knowledge of physical problems is uniquely human. We presented 9 capuchin monkeys, 6 bonobos, 6 chimpanzees and 48 children with two versions of a broken-string problem. In the standard condition, participants had to choose between an intact and a broken string as means to a reward. In the critical condition, the functional parts of the strings were covered up and replaced by perceptually similar, but non-functional cues. Apes, monkeys and young children performed significantly better in the standard condition in which the cues played a functional role, indicating knowledge of the functional properties involved. Moreover, a control experiment with chimpanzees and young children ruled out that this difference in performance could be accounted for by differences of perceptual feedback in the two conditions. We suggest that, similar to humans, nonhuman primates partly rely on abstract concepts in physical problem-solving
Combining language and space: sentence bisection in unilateral spatial neglect.
Get PDFIn line bisection right-brain-damaged patients with left spatial neglect show a rightward deviation, with respect to the line\u27s physical center. In word bisection ortho-phonological features of the stimulus\u27 final (right-sided) part modulate performance of both patients and healthy participants (Veronelli, Vallar, Marinelli, Primativo, & Arduino, 2014). We investigated the role of linguistic factors in sentence bisection, in patients with and without neglect, and control participants. The effects of information in the rightsided part of the sentence (Experiment #1), and of lexical and syntactic violations (Experiment #2) were assessed. Neglect patients showed an overall rightward bias, larger than those of patients without neglect and controls. The neglect patients\u27 bias was modulated by stimulus type, decreasing from lines, to letter strings and to all types of sentences. In sum, in visuo-manual sentence bisection a basic linguistic mechanism, such as sentence readability, brings about a more leftward appreciation of the stimulus, reducing the neglect patients\u27 rightward bias
Nonhuman gamblers: lessons from rodents, primates, and robots
Get PDFThe search for neuronal and psychological underpinnings of pathological gambling in humans would benefit from investigating related phenomena also outside of our species. In this paper, we present a survey of studies in three widely different populations of agents, namely rodents, non-human primates, and robots. Each of these populations offers valuable and complementary insights on the topic, as the literature demonstrates. In addition, we highlight the deep and complex connections between relevant results across these different areas of research (i.e., cognitive and computational neuroscience, neuroethology, cognitive primatology, neuropsychiatry, evolutionary robotics), to make the case for a greater degree of methodological integration in future studies on pathological gambling
Cortico-subcortical metabolic correlates of olfactory processing in healthy resting subjects
Get PDFA wide network of interconnected areas was previously found in neuroimaging studies involving normal as well as pathological subjects; however literature seems to suffer from a lack of investigation in glucose metabolism behaviour under olfactory condition. Thus, the present work describe for the first time a pure olfactory related brain response of metabolism by using 18F-fluorodeoxyglucose-Positron Emission Tomography/Computer Tomography in eleven resting subjects undergoing a neutral and a pure olfactory condition. By contrasting these experimental phases, it was possible to depict a re-organization pattern of default mode network structures in a relatively ecological environment. Moreover, by correlating such pattern with a battery of validated olfactory and neuropsychological tests, our work allowed in showing peculiar correlation data that could cluster the subjects sample in a certain range of normality. We believe the present study could integrate the current knowledge in olfactory research and could be a start-up for future contributions
Cooperative navigation in robotic swarms
No full textWe study cooperative navigation for robotic swarms in the context of a general event-servicing scenario. In the scenario, one or more events need to be serviced at specific locations by robots with the required skills. We focus on the question of how the swarm can inform its members about events, and guide robots to event locations. We propose a solution based on delay-tolerant wireless communications: by forwarding navigation infor- mation between them, robots cooperatively guide each other towards event locations. Such a collaborative approach leverages on the swarm\u27s intrinsic redundancy, distribution, and mobility. At the same time, the forwarding of navigation messages is the only form of coop- eration that is required. This means that the robots are free in terms of their movement and location, and they can be involved in other tasks, unrelated to the navigation of the searching robot. This gives the system a high level of flexibility in terms of application scenarios, and a high degree of robustness with respect to robot failures or unexpected events. We study the algorithm in two different scenarios, both in simulation and on real robots. In the first scenario, a single searching robot needs to find a single target, while all other robots are involved in tasks of their own. In the second scenario, we study collective navigation: all robots of the swarm navigate back and forth between two targets, which is a typical scenario in swarm robotics. We show that in this case, the proposed algorithm gives rise to synergies in robot navigation, and it lets the swarm self-organize into a robust dynamic structure. The emergence of this structure improves navigation efficiency and lets the swarm find shortest paths