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Utilizzo del test di evocazione dei metaboriflessi come indicatore dello stato di salute/complicanza: studio longitudinale su di una popolazione affetta da paraplegia
Get PDFSpinal cord injured (SCI) subjects show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac pre-load and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation to improve the cardiac output (CO). The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals (7 males and 2 females) were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4±683.9 mlmin-1 vs. 220.5±745.4 mlmin-1, p<0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects
Global normal forms and global properties in function spaces for second order Shubin type operators
Get PDFWe investigate the reduction to global normal forms of second order Shubin(or G) type differential operators P(x;D) in functional spaces on Rn. We describe the isomorphism properties of normal form transformations, introduced by L. Hormander for the study of affine symplectic transformations acting on pseudodifferential operators, in spaces like the Schwartz class, the weighted Shubin-Sobolev spaces and the Gelfand-Shilov spaces. We prove that the operator P(x;D) and the normal form PNF(x;D) have the same regularity/solvability and spectral properties. We also study the stability of global properties of the normal forms under perturbations by zero order Shubin type pseudodifferential operators and, more generally, by operators acting on S(Rn) and admitting discrete representations. Finally, we study Cauchy problems on Rn globally in time for second order hyperbolic equations P(x;D)+R(x;D), where P(x;D) is a second or der self-adjoint globally elliptic Shubin pseudodifferential operator and R(x;D) is a first order pseudodifferential operator
East to East. Dinamiche domestico-internazionali, obiettivi bidirezionali e strategie economiche nelle relazioni fra Asia Orientale ed Europa centro-orientale
Get PDFThe research studies the economic relationship between Central Eastern Europe and East Asia, in particular the foreing trade and the foreign direct investments, by analyzing their political influences and implications.
The research is divided in two parts. The first part involves the relationship between the two regions after the second world war until the events of 1989. The cold war and the sino-soviet split affected the economic bilateral ties in that period. The growth or the decrease of the foreign trade were the consequence of the choices made in the foreign policy field. The vents of 1989, however, definitely changed the relationship between Central Eastern Europe and East Asia.
The second part of the research involves the bilateral trade and foreign investmens made after the 1989. During the Nineties the trade exchanges decreased because the crisis that affected the Central Eastern Europe countries. During 2000s the relationship has become stronger than before thanks to the foreign direct investments made in Europe by Japanese, Korean and, recently, Chinese investors.
The future of the relationship between Central Eastern Europe and East Asia is uncertain, because the relevant differences between them, and depends from the choices the Asian giants will make next years
Le fonti greche di età bizantina per lo studio della Sardegna altomedievale (VI-XII secolo)
Get PDFThis work aims to offer a collection of Greek sources concerning
Sardinia between the sixth and twelfth century. The first part is an
introductory essay that illustrates the problems related to the
investigation of the "Byzantine Sardinia" and summarizes the data
obtained from the collected sources. The second part contains the
sources with commentary and bibliography; they have been classified
according three main categories: literary sources; documentary
sources; epigraphic sources
I consoli francesi in Sardegna nel decennio preunitario. Politica, economia e società
Get PDFThe center of attention of this thesis is the commercial relations between France, the island of Sardinia
and the city of Genoa, as well as the business ventures of French capitalists thanks to the support of
the most important businessmen in the two financial cities of the Kingdom of Sardinia (Genoa and
Turin) during the so-called Cavourian decade.
This work is based mainly on French both political and economical consular reports sent from
the post of Cagliari, one of the strategic Mediterranean ports.
The thesis is divided into four chapters.
The first chapter is entirely dedicated to the economic junctures that contributed to create a
wide and integrated French-Ligurian-Sardinian trading and industrial area.
The second chapter examines the commercial activity, the investment areas and the
entrepreneurial units and companies in Sardinia, where there was a strong presence of French and
Ligurian businessmen (mines, salines, agriculture, infrastructures, banks and so forth).
The third chapter recreates the setting (cities and coastal towns) where French consuls, viceconsuls
and consular agents were called to protect the French interests.
The work analyses also the social setting by offering a description of the condition of life and
economical problems that obliged people to strive for the annexation of Sardinia to an European main
power as France.
To conclude, the thesis describes the main aspects of the French community in Sardinia, mostly
composed by merchants. It includes the biographies of French consuls in Cagliari from 1848 to 1861
Innovation and entrepreneurship in organization studies
Get PDFThis work, following the conceptual recombination theory, by which ideas and concepts
are mentally merged to transform and extend knowledge, explores and summarizes
the current sources of academic literature, simultaneously engaging research in the fields
of entrepreneurship and creativity. A bibliometric co-citation analysis was applied to
identify the invisible colleges and the latent relationships among the most significant
papers. Multivariate analyses including cluster, latent class, multidimensional scaling,
and Pathfinder were combined to map the nodes positioning the literature. The goal
of this study is (1) to increase the awareness of scholars by detecting and visualizing the
intellectual structure of the shared ground among both sets of literature; (2) to identify
the connected schools of thought, methods, constructs, and theories to problematize or
literature gaps to be filled; (3) to reveal the network structure the central, bridge, and
peripheral nodes and to hypothesize trailblazing trends, sidings, or forgotten contributions;
and (4) to generate, thanks to a creativity grant, new insights to enable entrepreneurs
to explore new frontiers. Using creativity techniques and a panel of experts
in support, 26 keywords were generated, extracted, assessed and exploited to identify the
research unit of 1533 articles. Following a further evaluation process, 73 major co-cited
items were finally selected. Given the transverse nature of the creativity domain and of
the search for academic interdisciplinary comminglings, data were collected from Science
(SCI), Social Sciences (SSCI) and Arts and Humanities (A&HCI) citation indices for the
1991-2013 period
Seismic reflection imaging of near surface structures using the Common Reflection Surface (CRS) Stack Method
Get PDFThis PhD thesis aims to evaluate whether the
Common-Refl
ection-Surface (CRS) stack method can be considered as a more cost efficient processing alternative to the conventionally used Common Midpoint (CMP) stack method for processing of shallow and ultrashallow reflection data.
The CRS stack is a seismic imaging method established for oil and gas exploration that is similar in concept to the conventional CMP stack method. Unlike the CMP stack,
the CRS stack process is not confined to single CMP gathers (offset direction), but also includes neighbouring CMPs (midpoint direction) into the so-called CRS supergathers.
The use of CRS supergathers enables stable \data-driven", i.e. without human interactions, velocity analysis and residual static corrections, avoiding the poorly-automated
and time-consuming processing steps that are instead required when implementing conventional CMP processing. This makes the seismic imaging process more compatible
with budgets available for near-surface geophysical investigations. Improving seismic
imaging of near-surface reflection data, while at the same time reducing processing costs and human interaction during processing was the principal objective which guided
my work. To investigate the advantages and limitations of exporting the CRS stack from the hydrocarbon
exploration field to the near-surface scale, I have firstly analysed and adapted the characteristics of the CRS to the requirements of near-surface reflection data. Then, I have compared the results (seismic sections and velocity fields) obtained by processing
with the CMP and the CRS stack methods for two real field datasets (P- and SH-wave)and two synthetic datasets that exhibited very large vertical velocity changes. Finally,
I have proposed some original solutions that overcome several of the issues encountered when using CRS stack with near-surface data. The P-wave dataset was collected as part of a hydrogeological investigation with the aim
of delineating the hydrogeological framework of a paleolake environment to a depth of few hundred metres. Using the CMP method, several nearly horizontal reectors with onsets from 60 to about 250 ms were imaged. The CRS stack produced a stacked section with greater coherency and lateral continuity than the CMP section, but also spurious
alignments of seismic energy which hinder interpretation. Weighing the CRS stacked section with the corresponding CRS coherence and number of CRS stacked traces leads
to a considerable reduction of the spurious alignments, resulting in a seismic section more suited to delineate the aquifer and its confining units. The SH-wave ultrashallow dataset was collected to support a geotechnical study to a
depth of 10 m. The obtained CMP stacked section imaged a dipping bedrock interface below four horizontal re
ectors in unconsolidated, very low velocity sediments. The
vertical and lateral resolution was very high, so that despite the very shallow depth the resulting CMP stacked section showed the well-defined pinchout of two layers at less than 10 m depth. The CRS stack improved the continuity of the shallowest reector but showed an excessive smearing effect with some reector portions, including the pinchout,
unresolved and not as well defined as in the (very detailed) CMP counterpart. Restricting the CRS stack process to single CMP gathers, preserving the CRS-supergather for the search of stacking parameters, produced a time section very similar to the CMP counterpart. In both cases, I swiftly obtained the CRS stacked sections in a fully automatic way,
so with a cost/benefit ratio considerably more advantageous than that of the CMP sections, which required time-consuming prestack velocity analysis as well as residual
static corrections. Moreover, using the kinematic wave field attributes determined for each stacking operation I reconstructed velocity fields matching the ones estimated with the CMP processing, even if this required a greater amount of work than that required to produce the CRS stacked sections. Finally, using two synthetic datasets, I addressed the issue of the crossing reection events that appear in data acquired in soils characterized by strong vertical velocity gradients. Although a matter debate for decades, this is an issue still unresolved by use
of the conventional CMP method. Using the first synthetic dataset I showed that unlike in conventional CMP processing which cannot accurately process crossing reflection events without generating distortions and artefacts, the data-driven CRS stack imaging process considerably restricts their generation, limiting the reduction of signal-to-noise ratio and of temporal resolution in stacked traces. With the second synthetic dataset I simulated a data acquisition reproducing a case history with a high-velocity contrast in the first 5 m depth. The CRS results that I obtained from the modelled data demonstrated
that the CRS stack method may be a reliable alternative for processing crossing reection events, definitely easier and faster than the construction of complicated velocity
functions and/or the separated processing of the crossing events. By comparing these results with those obtained using the CMP method I obtained other interesting
results, which, however, to validate would necessitate the use of real datasets. The findings of this present study demonstrates that the CRS stack could represent a
significant step forward for the reduction of the costs involved in shallow and ultrashallow
seismic reflection data processing, one which does not compromise the quality of results. Both these conditions being essential to the increased acceptance of the seismic reection method as a routine investigation method for use in shallow and ultrashallow seismics
Geomorfologia del Margine Continentale della Sardegna meridionale
Get PDFThe study submitted in this thesis is related to the continental margin of southern Sardinia, including the continental platform and the upper portion of the continental slope to a depth of about 2000 meters, is included within the Gulf of Cagliari, limited to the west by Capo Teulada and on the east by Capo Carbonara. The continental margin of southern Sardinia has been investigated for the first time through high resolution morphobatimetric (multibeam) data not interpolated. Have been defined Geo Risks associated with characteristics of escarpment‟s gravitational processes and the dynamics of channeled flows that affect the evolution of systems of canyons. The multibeam data have been acquired during two cruises: MaGIC Canale di Sardegna 2009 and MaGIC Sardegna
2010, whit the research ship “Universitatis”; Subbottom Profile data have been acquired to support the geological interpretation. The classification of the morphobatimetric elements identified the continental shelf, the slope, areas of diffused erosion, canyons and channels and areas affected by big submarine landslides. The detailed morphometric analysis carried out for each system of canyons and channel offered further information on the evolution dynamics and on the state of activity of the margin. Were detected evidence related to
uplift movements for the Sarroch Canyon, which present meander features and at least three orders of terraces. In the Pula Canyon area was observed the absence of intra-channel storage, index of tectonic activity related to the recent evolution of the western margin of the Gulf of Cagliari. Have been studied in detail five great submarine landslides in the Gulf of Cagliari, including the margin between the continental shelf and the upper continental
slope. Models have been proposed of the evolutionary dynamics and triggering of landslides, related the slowly tectonic influence, the presence of hydrates, within the
sedimentary package, and finally the seismic triggering as the main factor of initiation of underwater landslide
Lesioni degenerative e meccanismi di riparo della superficie oculare: lo pterigio e le deficienze delle cellule staminali del limbo (LSCD). Studio immunoistochimico e tecniche di coltura cellulare
Get PDFPterygium is a surface ocular lesion that is associated with chronic UV exposure, characterized by proliferation, inflammatory infiltrates, fibrosis, angiogenesis and extracellular matrix remodeling. The Angiotensin converting enzyme (ACE or ACE I) is the major component of the Renin-angiotensin system (RAS) converting the inactive decapeptide Angiotensin I (Ang I) to the active octapeptide Angiotensin II (Ang II). Besides this “classical role”, it can act as transcriptional regulator in response to external stimuli that may lead to cell damage and tissue remodeling. Due to this role, it can be internalized into the nuclear compartment to act as transcriptional factor for proteins involved in the inflammatory response. The aim of the present study was to determine ACE expression and localization in pterygium and culture pterygium cells by immunohistochemistry. The results demonstrated nuclear immunolocalization of ACE in pterygium compared to normal conjunctival in histological sections. ACE was not detected in the nuclei of subcultivated pterygium epithelial cells. The nuclear localization of ACE may be correlated with an anti-inflammatory path mediated by activation of its transcriptional role.
The human ocular surface is characterized by a continuous non-keratinized epithelium providing the eye with its first line of defense against infection and trauma. Corneal epithelial integrity and transparency are maintained by the stem cells (SCs) that reside in the limbus. However, when the limbus is extensively damaged, stem cell activity is compromised, resulting in a condition known as limbal stem cell deficiency (LSCD). This disease is characterized by corneal neovascularization, conjunctival epithelial ingrowth, chronic inflammation which impair vision. The aim of this study was to reconstruct in vitro organ culture models of human hemi-corneas (epithelium+stroma) on amniotic membrane, using primary keratocytes and limbal stem cells derived by human cornea. The results demonstrated that the complex represented by a well-differentiated epithelium taken together with a model resembling stroma, has developed on the surface of these hemi-corneas. Further investigation will be necessary to validate these models of hemi-corneas for pharmacotoxicology testing and therapeutic applications
Fisiologia e fisiopatologia della insufficienza venosa cerebrospinale: proposta di nuovi criteri diagnostici
Get PDFBackground: The physiological meccanisms thath influence the venous drainage of the extracranial venous system could be investigated by ecoDoppler sonography.
The alterations of phsyological meccanism of extracranial venous drainage
rappresents the physiopathological substract of CCSVI.
Patients with SM have shown to have a higher prevalence of CCSVI.
Objective: to study the physiology and physiopatology of the venous drainage trough the extracranial venous system using ecoDoppler sonography and to propose new criteria to define a condition of CCSVI
Methods: Extracranial ECD were carried out in 126 enrolled subjects (63 healthy control and 63 subjects with multiple sclerosis matched by gender and age).
Prevalence rates for CCSVI were calculated using Zamboni criteria and using two new criteria (Giugular Respiratory Index and Giugular Subclavian Index) based on physiology of extracranial venous drainage.
Results: CCSVI prevalence using Zamboni criteria was 63% in SM and 44% in HC (P 0,03*), the prevalence using new criteria was 44% and 36% in SM ( respectively for GRI and GSI) and 9% and 3% in HC (P <0,0001 ****).
Conclusions: our findings are consistent with an increased prevalence of CCSVI in MS with modest sensitivity and specificity using Zamboni criteria and with high specificity using new criteria (Giugular Respiratory Index a nd Giugular Subclavian Index). Our findings point against CCSVI having a primary causative role in the development of MS