1,152 research outputs found

    A cerebral bridge from olfactory cognition to spatial navigation

    Get PDF
    An evolutionary paradox is the variability of the olfactory bulb size, in contrast to the other brain regions, which are sized proportionally to the peripheral function. This variability seems to be the result of selection for the olfactory function. This disagreement may derive from considering smell as a sense linked to odorous discrimination. In many vertebrates and in terrestrial and marine mammals, the sense of smell has evolved into functions related to the eco-localization. So, if the olfactory function involves spatial perception and navigation, this, couldexplain the proportional discrepancy between the olfactory bulb and olfactory cortex. Humans are able to discriminate a spatial position as a function of olfactory cues. Vice versa, in neurodegenerative syndromes the orientation capacity and olfactory perception are impaired. This leads us to think that could be a common cross-modal processing, of phylogenetic origin, which links olfactory perception and spatial orientation. Starting from these theoretical assumptions, we conducted a basic research, on 100 healthy subjects, investigating, through both behavioral and electroencephalographic data, the connection between spatial memory span and olfactory spatial memory span. Subjects were assessed through a three-condition task: normal Corsi Block Test (CBT), ‘Olfactory’ Block Test (OBT) and a ‘Semantic-Olfactory’ Block Test (SOBT). CBT consisted in a test on spatial memory span; OBT consisted in a presentation a spatial sequences of 9 different odorants (i.e., Eucalyptol, Carvone, Eugenol, Isoamyl Acetate, Geraniol, Phenethyl Alcohol, Acetophenone, Cinnamon, Hexanal) instilled on paper square not recognizable by any sign, positioned on a CBT, and showed in a spatial navigation way, and SOBT consisted of a semantic labelled of olfactory spatial navigation. A GLM repeated measure highlighted significant differences during the three conditions. Subjects had different SPANs due to different conditions. The Semantic olfactory memory SPAN was inferior respect Olfactory span and Spatial Span. Furthermore was found a significant positive correlation between the three condition. The 5 subjects with higher SPAN scores, 5 with medium scores and the 5 subjects with lower SPAN scores were recruited to investigate ERP components elicited during the cross-modal task. Subjects had to perform, during a high-density EEG recording, an olfactory task (administered through the device US2017127971 (A1) “? 2017-05-11), an EEG Posner spatial cueing task and a go/no-go olfactory semantic categorization task. The results of this study will be discussed in light of a theoretical connection between these three aspects of cortical functions that seem strongly interconnected

    Age-related changes of elastic fibers in shoulder capsule of patients with glenohumeral instability: A pilot study

    Get PDF
    Background. Recurrent shoulder dislocations occur much more frequently in adolescents than in the older population but a clear explanation of this incidence does not exist. The aim of the present study was to define the age-related distribution of the elastic fibers (EFs) in the shoulder capsule's extracellular matrix as a factor influencing shoulder instability. Materials and Methods. Biopsy specimens were obtained from the shoulder capsule of patients divided preoperatively into three groups: Group 1 consisted of 10 male patients undergoing surgery for unidirectional traumatic anterior instability (TUBS); Group 2 consisted of 10 male patients undergoing surgery for multidirectional instability (MDI); Group 3 represents the control, including 10 patients with no history of instability. In addition to the group as a whole, specific subgroups were analyzed separately on the basis of the age of subjects: > 22 or < to 22 years. All the samples were analyzed by histochemical (Weigert's resorcinol fuchsin and Verhoeff's iron hematoxylin), immunohistochemical (monoclonal antielastin antibody), and histomorphometric methods. Results. Both the elastin density and the percentage of area covered by EFs were significantly higher in younger subjects (<22 years old). Furthermore, the elastin density and the percentage of area covered by EFs were significantly higher in specimens of group of patients affected by multidirectional shoulder instability in comparison to the other two groups. Conclusion. Data of the present study confirmed the presence of an age-related distribution of EFs in the human shoulder capsule. The greater amount of EFs observed in younger subjects and in unstable shoulders could play an important role in predisposing the joint to first dislocation and recurrence

    Age-related changes of elastic fibers in shoulder capsule of patients with glenohumeral instability: A pilot study

    Get PDF
    Background. Recurrent shoulder dislocations occur much more frequently in adolescents than in the older population but a clear explanation of this incidence does not exist. The aim of the present study was to define the age-related distribution of the elastic fibers (EFs) in the shoulder capsule's extracellular matrix as a factor influencing shoulder instability. Materials and Methods. Biopsy specimens were obtained from the shoulder capsule of patients divided preoperatively into three groups: Group 1 consisted of 10 male patients undergoing surgery for unidirectional traumatic anterior instability (TUBS); Group 2 consisted of 10 male patients undergoing surgery for multidirectional instability (MDI); Group 3 represents the control, including 10 patients with no history of instability. In addition to the group as a whole, specific subgroups were analyzed separately on the basis of the age of subjects: &gt; 22 or &lt; to 22 years. All the samples were analyzed by histochemical (Weigert's resorcinol fuchsin and Verhoeff's iron hematoxylin), immunohistochemical (monoclonal antielastin antibody), and histomorphometric methods. Results. Both the elastin density and the percentage of area covered by EFs were significantly higher in younger subjects (&lt;22 years old). Furthermore, the elastin density and the percentage of area covered by EFs were significantly higher in specimens of group of patients affected by multidirectional shoulder instability in comparison to the other two groups. Conclusion. Data of the present study confirmed the presence of an age-related distribution of EFs in the human shoulder capsule. The greater amount of EFs observed in younger subjects and in unstable shoulders could play an important role in predisposing the joint to first dislocation and recurrence

    Support to Design for Air Traffic Management: An Approach with Agent-Based Modelling and Evolutionary Search

    Get PDF
    To enhance Air Traffic Management (ATM) and meet the future traffic demand and environmental requirements, present ATM system is going to be modified (SESAR Joint Undertaking, 2017), designing new services to be integrated in future architecture considering the evolution of present fragmented structure of the airspace and the entanglement of air routes. Such a change process is complicated due to the nature of ATM, which is a large-scale Socio-Technical System (STS), typically involving a complex interaction between humans, machines and the environment. In such kind of systems, managing their evolution is a complex and difficult task since the social and technical implications of any proposed concept should be fully assessed before a choice is made whether or not to proceed with the related development. Often, simulation tools are also used to support the design of the concept itself by enabling what-if-analyses. However, these may be too effort and time consuming due to the exponential growth of the required analysis cases. A quite common mismatch between the performance evaluations in simulated conditions and those achieved in real life is represented by the partial assessment of human aspects that can be performed throughout the new concept lifecycle from its lowest maturity level up to “ready to market”. The proposed work defines an approach to support the design of new ATM solutions, including the evaluation on human behaviour. The approach adopts a combined paradigm, which involves Agent-Based Modelling and Simulation (ABMS) to specify and analyse the ATM models, and Agent-based Evolutionary Search (AES) to optimize the design of the new solutions. A specific case study is used to demonstrate the effectiveness of the proposed approach. Transition from Direct Routing Airspace (DRA) to Free Routing Airspace (FRA), respectively described by Solution #32 and Solution #33 in the SESAR solutions catalogue (SESAR Joint Undertaking, 2017), is used for both validation and experimentation activities. In detail, the proposed experimentation case regards the design of sector collapsing/decollapsing configuration to optimize controller workloads. The achieved results are presented and discussed

    MA-XRF measurement for corrosion assessment on bronze artefacts

    Get PDF
    In this study, an innovative portable macro X-Ray Fluorescence (MA-XRF) scanner prototype has been employed in order to gain information on composition and distribution of corrosion products artificially grown on Cu-based coupons. First results have shown the importance of using artificially corroded reference samples before any assessment on archaeological artefacts. Moreover, the prototype used demonstrated to be a powerful tool for understanding complex corrosion processes which might occur on Cu-based alloys. The scanner was able to detect light elements as S and Cl, essential for studying the distribution of specific corrosion compounds. Using imaging techniques, it was possible to observe a gradient in Cu elemental maps intensity caused by the overlapping of a thicker corrosion product layer

    MA-XRF measurement for corrosion assessment on bronze artefacts

    Get PDF
    In this study, an innovative portable macro X-Ray Fluorescence (MA-XRF) scanner prototype has been employed in order to gain information on composition and distribution of corrosion products artificially grown on Cu-based coupons. First results have shown the importance of using artificially corroded reference samples before any assessment on archaeological artefacts. Moreover, the prototype used demonstrated to be a powerful tool for understanding complex corrosion processes which might occur on Cu-based alloys. The scanner was able to detect light elements as S and Cl, essential for studying the distribution of specific corrosion compounds. Using imaging techniques, it was possible to observe a gradient in Cu elemental maps intensity caused by the overlapping of a thicker corrosion product layer

    Differential X-ray attenuation in MA-XRF analysis for a non-invasive determination of gilding thickness

    Get PDF
    When investigating gilded artifacts or works of art, the determination of the gilding thickness plays a significant role in establishing restoration protocols or conservation strategies. Unfortunately, this is done by cross-sectioning the object, a destructive approach not always feasible. A non-destructive alternative, based on the differential attenuation of fluorescence radiation from the sample, has been developed in the past years, but due to the intrinsic random nature of X-rays, the study of single or few spots of an objects surface may yield biased information. Furthermore, considering the effects of both porosity and sample inhomogeneities is a practice commonly overlooked, which may introduce systematic errors. In order to overcome these matters, here we propose the extrapolation of the differential-attenuation method from single-spot X-ray fluorescence (XRF) measurements to macro-XRF (MA-XRF) scanning. In this work, an innovative algorithm was developed for evaluating the large amount of data coming from MA-XRF datasets and evaluate the thickness of a given overlapping layer over an area. This approach was adopted to study a gilded copper-based buckle from the sixteenth to seventeenth century found in Rome. The gilded object under investigation was also studied by other analytical techniques including scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). Previous results obtained from SEM-EDS were used to confront the data obtained with the proposed methodology and validate it. MA-XRF elemental distribution maps were fundamental in identifying and choosing sampling areas to calculate the thickness of the gilding layer, avoiding lead islands present in the sample that could negatively influence the results. Albeit the large relative standard deviation, the mean thickness values fell within those found in literature and those obtained from previous studies with SEM-EDS. Surface fissure has been found to deeply affect the results obtained, an aspect that is often disregarded
    corecore