651 research outputs found

    An Examination of Hippocampal and Prefrontal Contributions to Spatial Learning and Memory using Immediate Early Gene Imaging

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    The hippocampus and medial prefrontal cortex are two brain regions which have repeatedly been linked to spatial learning and memory processing; however, the precise roles of individual sub-regions within these areas continue to be debated. The Morris water maze is a well-known behavioural task used to measure spatial memory. Despite its popularity, the type of spatial information animals encode and ultimately rely on for accurate navigation in this task remains unclear. Therefore, the primary objectives of this thesis were to conduct an in-depth investigation into the use of navigation strategies during memory encoding and retrieval in the water maze, and to characterise the specific contributions of the hippocampus and medial prefrontal cortex to these processes using Immediate Early Genes (IEG) imaging. In addition, we investigated the mechanisms underlying neuronal activation by inhibiting ionotropic glutamate receptors (NMDA and AMPA) during or after spatial learning. We found novel evidence that the salience (or noticeability) of environmental cues significantly impacted the type of learning strategy used (i.e. simple or complex), and that increased training led to more flexible responding (i.e. strategy switching). We also discovered that NMDA receptor-mediated activation in area CA1 (indexed by Zif268) was tightly linked to learning-related plasticity, and activation in CA3, prelimbic and anterior cingulate cortices was strongly associated with flexible spatial memory recall (i.e. pattern completion). Finally, we revealed that spatial memory deficits induced by NMDA receptor blockade could be partially prevented by extended environmental experience

    Acoustic parameters of the Municipal Theatre of Piacenza shown on different ways of representation

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    The Italian Opera theatres are always subject to scientific studies that try to investigate as deeply as possible this historical heritage to preserve the architectural and acoustical information for future generations. This paper deals with two ways of data representations based on the outcomes derived from the variety of equipment used during the measurements. In particular, a methodology in line with standards and regulations has been introduced to representing the graphs of the main acoustical parameters; besides, a video of the real-time room impulse response (RIR) has been snapped with a few shots in place of visualizing the sound reflections that occurred inside the entire volume. After a brief description of the historical background of the Municipal theatre of Piacenza, the authors introduce the two methods just discussed to highlight the completeness of data representation regarding any type of room that is intended to be analyzed acoustically

    3dof representation of the acoustic measurements inside the Comunale-Pavarotti Theatre of Modena

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    The investigation of the acoustics inside the Italian Opera theatres has been undertaken by scholars in order to deepening their scientific studies on the architectural and cultural heritage. This paper deals with alternative ways of how to represent acoustic data, in particular by adding a 3dof representation of the impulse response (IR) besides the graphs related to the main acoustic parameters in line with the standard requirements. The 3dof screen shots have been undertaken by an overlay elaboration, showing the particular architectural components of the theatre that contribute to the early and late sound reflections. A brief introduction of the historical background related to the Comunale-Pavarotti theatre of Modena has been given to understand the architectural characteristics of the entire structure

    Acoustic measurements of the Roman theatre of Pompei by mapping the sound reflections

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    The city of Pompei has been always subject to archaeological works during the last decades. However, the theatre that has been discovered in the urban environment has one of the best preserved cavea, although it lacks most of the scaenae frons. This paper deals with the acoustic measurements undertaken to study the behavior of this important monument through the main acoustic parameter outlined by ISO 3382-1, and to detect the direction of the early and late reflections characterizing the reverberation. This latest approach enabled the possibility to investigate the sound propagation thought the space with the employment of a multichannel spherical array microphone. The recorded impulse response (IR) has been analyzed in such a way to create an overlay video, given by the overlapping of the 360° image taken at the receiver position with the contour level of the sound decay after the impulse

    granulocyte transfusions a critical reappraisal

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    Granulocyte transfusions (GTs) are seldom used as a life-saving therapy for neutropenic patients with severe infections. Despite compelling evidence of GT efficacy in retrospective and prospective case series, no study has been successful in demonstrating a definite advantage for recipients in controlled clinical trials. This review critically revises some aspects emerging from past experience that might have weakened the evidence of GT benefits. Some specific issues relevant to the efficacy of this therapeutic approach, such as primary infection, delivered doses and schedules, and immunologic effects of GTs, are discussed. Importantly, the awareness of biologic effects accompanying the transfusion of neutrophils might support their use at standardized doses and may definitely convey significant advantages to the recipient patients

    Comparison Failure and Successful Methodologies for Diffusion Measurements Undertaken inside Two Different Testing Rooms

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    The scattering phenomenon is known to be of great importance for the acoustic quality of a performance arts space. The scattering of sound can be achieved in different ways: it can be obtained by the presence of architectural and/or decorating elements inside a room (e.g., columns, statues), by the geometry and roughness of a surface (e.g., Quadratic Residue Diffuser (QRD)) and by the diffraction effect occurring when a sound wave hits the edges of an obstacle. This article deals with the surface scattering effects and the diffusion phenomenon only related to MDF and plywood panels tested by disposing the wells both horizontally and vertically. The test results undertaken inside a semi-reverberant room and inside a large reverberant room have been compared to highlight the success and the failure of the measuring methodologies. In detail, according to the existing standards and regulations (i.e., ISO 17497—Part 2), diffusion measurements have been undertaken on a few selected types of panel: two QRD panels (made of Medium Density Fiberboard (MDF) and plywood) with and without a smooth painted solid wood placed behind the QRD. The panels have been tested inside two rooms of different characteristics: a semi-anechoic chamber (Room A) and a large reverberant room (Room B). The volume size influenced the results that have been analyzed for both chambers, showing an overlap of reflections on panels tested inside Room A and a clear diffusion response for the panels tested inside Room B. In terms of the diffusion coefficient in all the octave bands between 125 Hz and 8 kHz, results should not be considered valid for panels tested in Room A because they were negatively impacted by extraneous reflections, while they are reliable for panels tested in Room B

    Time domain diffuse optical spectroscopy: In vivo quantification of collagen in breast tissue

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    Time-resolved diffuse optical spectroscopy provides non-invasively the optical characterization of highly diffusive media, such as biological tissues. Light pulses are injected into the tissue and the effects of light propagation on re-emitted pulses are interpreted with the diffusion theory to assess simultaneously tissue absorption and reduced scattering coefficients. Performing spectral measurements, information on tissue composition and structure is derived applying the Beer law to the measured absorption and an empiric approximation to Mie theory to the reduced scattering. The absorption properties of collagen powder were preliminarily measured in the range of 600-1100 nm using a laboratory set-up for broadband time-resolved diffuse optical spectroscopy. Optical projection images were subsequently acquired in compressed breast geometry on 218 subjects, either healthy or bearing breast lesions, using a portable instrument for optical mammography that operates at 7 wavelengths selected in the range 635-1060 nm. For all subjects, tissue composition was estimated in terms of oxy- and deoxy-hemoglobin, water, lipids, and collagen. Information on tissue microscopic structure was also derived. Good correlation was obtained between mammographic breast density (a strong risk factor for breast cancer) and an optical index based on collagen content and scattering power (that accounts mostly for tissue collagen). Logistic regression applied to all optically derived parameters showed that subjects at high risk for developing breast cancer for their high breast density can effectively be identified based on collagen content and scattering parameters. Tissue composition assessed in breast lesions with a perturbative approach indicated that collagen and hemoglobin content are significantly higher in malignant lesions than in benign ones

    ROLE OF CHAPERONES IN HEALTHY BOWEL AND IBD.

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    The chaperoning system is the wole complement of chaperones, co-chaperones and chaperone cofactors of the body that preserves cell and tissue homeostasis. Its structural and/or functional defects can cause pathologic conditions, nemed chaperonopathies. Large bowel homeostasis includes a healthy status of the mucosal tissues and the microbiota. An alteration of one of them may determine, in turn, modifications of the other. Molecular chaperones of bacteria and human origin have been implicated in inflammatory bowel disease (IBD). In IBD chaperone levels usually increase and their cellular and subcellular loclization change. This is considered a physiological stress-response of mucosal cells to inflammation. However, chaperones also play active roles in IBD pathogenesis, e.g. perpetuate inflammation. Therefore, IBD can be classified among the chaperonopathies. This classification opens the door to the design and application of new forms of treatment targeting the chaperones, namely chaperonopathy
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