Impact of Patient-Specific Inflow Boundary Conditions and Concentration Initialization on Hemodynamics and Low-Density Lipoproteins Transport in the Thoracic Aorta

The complex hemodynamics observed in the human aorta make this district a site of election for an in depth investigation of the relationship between fluid structures, transport and patho-physiology. In fact, it is well known that hemodynamics play an important role in the mass transport of blood specimen, and in turn, in their transfer to the vascular wall and ultimately in the localization of vascular disease in areas of complex arterial flow. In particular, the accumulation of lipoproteins in the arterial intima is a hallmark of atherosclerosis. Low-density lipoproteins (LDL) are the most abundant atherogenic lipoproteins in plasma and high plasma levels of LDL are causally related to the development of atherosclerosis. Advanced computational fluid dynamics coupled with medical imaging allows to combine the anatomical and hemodynamic inputs to realistic, fully personalized flow simulations to study local hemodynamics in arteries. Such an approach represents an effective way when addressing the still open questions about the role of blood-side LDL transfer to the arterial wall in atherogenesis. In particular, personalized computational models have been proposed to study LDL blood-to-wall transfer in the aorta, a district of election for the study of the relationships between the intricate local hemodynamics, LDL transport and disease. However, computational hemodynamics requires some assumptions that could affect the solutions of the equations governing blood flow and the aortic LDL transport and wall transfer. In previous studies of my research group, has been demonstrated that different strategies in applying boundary conditions (BCs) derived from phase-contrast MRI (PC-MRI) measurements could lead to different results in terms of distribution of near-wall and intravascular flow quantities. Additionally, a paucity of data characterizes the literature concerning the BCs and initial conditions (ICs) adopted to model LDL transport. In this contest, my thesis project have been focalized in analysing the impact that different possible strategies of applying (1) PC-MRI measured data as inflow BCs, and (2) LDL concentration profiles as ICs, have on LDL blood-to-wall transfer modelling in the human aorta. Technically, two different inflow BCs are generated, by imposing at the ascending aorta inflow PC-MRI measured 3D velocity profiles or idealized (flat) velocity profiles. In this way, the sensitivity of blood-to-wall LDL transfer to the inflow BC is explored, as the inflow BC influences LDL advective transport. The impact of applied BC-IC strategies on LDL blood-to-wall transfer has been evaluated in terms of computational costs and LDL polarization profiles at the luminal surface. Moreover, by virtue of the reported high LDL concentration in correspondence of disturbed shear regions, here a co-localization analysis with areas exposed to atheroprone wall shear stress (WSS) phenotype has been conducted as a “physics consistency check”. The results of my research would contribute to clarify which is (1) the level of detail obtained from measured flow data to be used as inflow BC, and (2) the plausibility of hypotheses on LDL concentration to be used as IC strategy, to satisfactorily simulate mass transport/transfer in personalized complex hemodynamic models of human aorta

Country Image, Tourist Satisfaction, and Future Visit and Product Purchase Intentions: An Integrative Model

Place image is a matter of strong and current interest. This study advances existing knowledge by developing a model that integrates product, tourism, and general country images (GCI) of place, to identify antecedents and effects of tourist satisfaction in the tourism and product domains. Results indicate that travelers compartmentalize their beliefs, forming their perceptions of trip satisfaction directly from the destination image of a place, and indirectly through the influence on that image of the places general and producer-based images. This study shows for the first time that the image people hold about, and the familiarity they have with, a country’s products provide a “summary” to form perceptions of the country as a tourism destination. Perhaps of most interest, results indicate that a satisfactory tourism experience is able not only to positively affect destination loyalty and word of mouth, but can also significantly influence post-visit intentions towards national products

MODELLAZIONE E ANALISI DELLA FLUX SWITCHING MACHINE

This thesis deals with the modelling and analysis of a flux switching machine 12/10, tailored for industrial applications. The analytical design of the flux switching machine 12/10 has been checked using a finite element software

The effect of mindfulness on creative thinking within organizations

Objectives Research on the effects of meditation practice on creativity performance is a new and promising area of research. Although this field is still young, there are already enough studies showing a correlation between Mindfulness training and improvements in creativity, especially in the field of organizational psychology. In this study, we aimed to determine the efficacy of a 6-week Mindfulnessbased intervention in improving creativity in organizations’ workers. Method For this longitudinal study, a 6-week specific protocol was used with a group of workers at the Polytechnic University of Catalunya, (n = 10). At the beginning of the training, the subjects were tested in Mindfulness and creativity using, respectively, the Five Facets Mindfulness Questionnaire and Crea tests. After the six sessions, the group was tested again. Results The analysis of the Crea test results showed an improvement in the subjects’ creative skills: On the first test, the mean total score was 573, and on the second test it was 694. Therefore, we can confirm that Mindfulness increases creativity; however, this improvement was observed only in the female subjects. Furthermore, we analyzed the effects of different aspects of Mindfulness on creativity and noted that the aspect of observation, (the ability to pay close attention to and carefully observe sensations, thoughts, and emotions) and the aspect of observation, (the ability to distance oneself from what is happening in the attentional field without instantly reacting to the stimulus), yielded better results in our research.Peer ReviewedPostprint (published version

Global analysis of the transcriptional regulation of Sinorhizobium meliloti cell cycle progression and study of cell cycle regulation during symbiosis with Medicago sativa

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.The complex [alpha]-proteobacterial cell cycle regulatory network is essential not only for faithful replication and segregation of the genome, but also to coordinate unique cellular differentiation events that have evolved as adaptations to the different lifestyles of this diverse group of bacteria. The soil-dwelling [alpha]-proteobacterium, Sinorhizobium meliloti, not only has to accurately coordinate the replication of its tripartite genome, but also must undergo a dramatic cellular differentiation in order to form an effective symbiosis with the legume Medicago sativa. Preliminary analyses have indicated that plasticity in the S. meliloti cell cycle regulatory network may be essential to symbiosis, but cell cycle research in S. meliloti has been hindered largely by lack of a method to obtain synchronous populations of S. meliloti. In this thesis, I present the first method to generate synchronous cultures of S. meliloti. I performed microarray gene expression analysis on synchronous populations of S. meliloti to gain a global view of transcriptional regulation of cell cycle events. This represents the first work of this kind done in an [alpha]-proteobacterium besides Caulobacter crescentus, which is the current model for [alpha]-proteobacterial cell cycle studies. The importance of transcriptional regulation of cell cycle progression was first discovered in C. crescentus and the work presented in this thesis highlights the conservation of cell cycle regulated gene expression in S. meliloti. I identified 462 cell cycle regulated transcripts in S. meliloti, which included genes involved in vital cell processes such as cell division, flagella biogenesis, replication and segregation of its tripartite genome as well as several putative cell cycle regulators. I compared the set of genes with cell cycle regulated transcripts identified in my analysis with the set identified in C. crescentus to generate a core set of 128 conserved genes demonstrating cell cycle regulated gene expression in both species. To determine which of the S. meliloti genes with cell cycle regulated transcripts might be part of the CtrA and DnaA regulons in S. meiloti, I performed CtrA and DnaA binding motif analysis. To understand the evolutionary significance of these CtrA and DnaA binding motifs, I looked at conservation of these motifs in homologous genes from several related [alpha]-proteobacteria. The results indicated that the putative CtrA regulon might be more evolutionarily constrained than the putative DnaA regulon. Organisms more closely related to S. meliloti or with more similar lifestyles demonstrated a much greater conservation of the CtrA binding motifs identified in S. meliloti. The CtrA binding motifs in S. meliloti identified by my analysis were not at all well conserved in C. crescentus, which was the most distantly related [alpha]-proteobacteria surveyed. These differences in cell cycle regulated transcription and the putative CtrA regulon between S. meliloti and C. crescentus thus appear to represent specific adaptations to the distinctive genome and unique intracellular symbiotic lifestyle of S. meliloti and illustrate the importance of S. meliloti as a model for cell cycle regulation in [alpha]-proteobacteria with similar intracellular lifestyles. The work presented in this thesis also describes the importance of CtrA regulation in S. meliloti during symbiosis with M. sativa. A crucial part of this symbiosis is a striking cellular differentiation (termed bacteroid differentiation), which includes changes in membrane permeability, cell elongation and branching, endoreduplication of the genome and loss of reproductive capacity and therefore a significant deviation from the free-living cell cycle program. Endoreduplication of the genome requires a decoupling of DNA replication and cell division, which could be achieved by down-regulation of the essential master cell cycle regulator CtrA. I tested the effects of CtrA depletion in S. meliloti and found that CtrA depletion induces a bacteroid-like state characterized by elongated and branched cells and highly elevated DNA content. I also show that S. meliloti CtrA has a comparable half-life to C. crescentus CtrA, but regulated proteolysis of CtrA may be different in the two species since we found CtrA proteolysis to be essential in S. meliloti. In addition, I demonstrate that the promoter and coding regions of C. crescentus ctrA cannot complement an S. meliloti ctrA chromosomal deletion during symbiosis even though they can do so in the free-living state. My attempts to identify the defects in the function C. cresentus ctrA promoter or coding region within M. sativa gave surprising results since S. melioti strains expressing C. crescentus CtrA from the S. meliloti ctrA promoter region and vice versa were able to establish an effective symbiosis with M. sativa. I discuss several possibilities to explain this apparent paradox, but further study is required to fully clarify this observation. Taken as a whole, my thesis work represents a significant advancement to the field of cell cycle research in S. meliloti and [alpha]-proteobacteria as a whole. The cell synchronization method I developed will greatly facilitate more comprehensive analysis of cell cycle regulation in S. meliloti. My microarray gene expression analysis provides a global view of cell cycle regulated transcription in S. meliloti, which can be used in more in-depth explorations of specific mechanisms of transcriptional regulation of cell cycle events in S. meliloti. Lastly, my study of CtrA function in S. meliloti establishes the importance of CtrA regulation during symbiosis with M. sativa.by Nicole J. De Nisco.Ph.D

The Effect Of Mindfulness On Creative Thinking Within Organizations

Objectives Research on the effects of meditation practice on creativity performance is a new and promising area of research. Although this field is still young, there are already enough studies showing a correlation between Mindfulness training and improvements in creativity, especially in the field of organizational psychology. In this study, we aimed to determine the efficacy of a 6-week Mindfulness-based intervention in improving creativity in organizations’ workers. Method For this longitudinal study, a 6-week specific protocol was used with a group of workers at the Polytechnic University of Catalunya, (n = 10). At the beginning of the training, the subjects were tested in Mindfulness and creativity using, respectively, the Five Facets Mindfulness Questionnaire and Crea tests. After the six sessions, the group was tested again. Results The analysis of the Crea test results showed an improvement in the subjects’ creative skills: On the first test, the mean total score was 573, and on the second test it was 694. Therefore, we can confirm that Mindfulness increases creativity; however, this improvement was observed only in the female subjects. Furthermore, we analyzed the effects of different aspects of Mindfulness on creativity and noted that the aspect of observation, (the ability to pay close attention to and carefully observe sensations, thoughts, and emotions) and   the aspect of observation, (the ability to distance oneself from what is happening in the attentional field without instantly reacting to the stimulus), yielded better results in our research

Rapport au Roi Souverain : rapport de la Commission d'Enquête ; A. M. le Secrétaire d'État de l'État Indépendant du Congo [31 octobre 1905]

Bakgrund: Den palliativa vården för hälso- och sjukvårdspersonal innebär att försöka uppnå den döende personens maximala livskvalitet och att lindra lidandet. Vården lutar sig mot det nationella vårdprogrammet för palliativ vård samt International Council of Nurses, ICN. Sjuksköterskans roll och uppgifter inom vården beskrivs där även de fyra hörnstenarna belyses. Syfte: Att belysa sjuksköterskornas upplevda svårigheter vid vård av patienter med palliativ diagnos. Metod: Examensarbetet är en litteraturöversikt baserad på Fribergs analysmetod. Denna litteraturöversikt inkluderar tio vetenskapliga artiklar som har sökts i databaserna CINAHL Complete och PubMed. Som en teoretisk utgångspunkt har Patricia Benners teori från novis till expert valts som en diskussion i resultatdiskussionen. Resultat: Sjuksköterskornas upplevda svårigheter av att vårda patienter med en palliativ diagnos resulterade i fyra huvudteman i litteraturöversikten; kommunikation, närstående och relation, vårdteamet samt kunskap och erfarenheter. Diskussion: Resultatet i litteraturöversikten har diskuterats utifrån Benners teori. Sjuksköterskornas upplevda svårigheter belystes genom fyra teman – kunskap och erfarenhet, närståendestöd, kommunikation mellan kollegor och gentemot patienten samt kultur som upplevd svårighet.Background: Palliative care for health professional means trying to achieve the maximum dying person's quality of life and ease suffering. The palliative care for health professionals means to try to achieve the dying person's maximum quality of life and alleviate suffering. The care inclined towards the Swedish national health care program for palliative care and the International Council of Nurses, ICN. The nurse's role and tasks in health care are described where even the four cornerstones elucidated. Aim: To elucidate the nurses perceived difficulties in nursing patients with palliative diagnosis. Method: The thesis is a literature review based on Friberg's analysis. This literature review includes ten scientific articles that have been searched in the databases CINAHL Complete and PubMed. As a theoretical base, Patricia Benner's theory from novice to expert was selected as a discussion of the results discussion. Results: The nurses perceived difficulties of caring for patients with a palliative diagnosis resulted in four main themes in the literature; communication, family and relationship, the health care team as well as knowledge and experience. Discussion: The results of the literature review are discussed based on Benner's theory. The nurses' perceived difficulties irradiated by four themes – knowledge and experience, family support, communication between colleagues and towards the patient as well the culture as perceived difficulties

Finite Element Modeling Application in Forensic Practice: A Periprosthetic Femoral Fracture Case Study

The incidence of periprosthetic fractures has rapidly increased in the last two decades and has been the cause of a large number of revision surgeries and permanent physical disability for many patients, as well as a significant socioeconomic burden for many nations. This research deals with a periprosthetic femur fracture real event, occurred following a total hip arthroplasty and treated with one of the most widespread internal fixation methods: the implant of a periprosthetic femur plate system. A Finite Element analysis was performed to investigate the implanted femur plate break after a short follow-up and to understand the plate break causes. Such events are currently object of forensic debate as more and more often hospitals, surgeons, and medical device manufacturers are denounced by patients to whom similar events occur. In this work, different load situations acting on the femur during daily and incidental activities were simulated, in order to validate the correct behavior of the plate, according to the intended use recommended by the manufacturer. The analysis demonstrates that the plate failure can occur in situations of unconventional loading such as that caused by stumbling and in presence of incomplete bone healing

Stereoselective Synthesis of Selenium-Containing Glycoconjugates via the Mitsunobu Reaction

A simple and efficient route for the synthesis of new glycoconjugates has been developed.The approach acts as a model for a mini-library of compounds with a deoxy-selenosugar core joinedto a polyphenolic moiety with well-known antioxidant properties. An unexpected stereocontroldetected in the Mitsunobu key reaction led to the most attractive product showing a natural Dconfiguration. Thus, we were able to obtain the target molecules from the commercially availableD-ribose via a shorter and convenient sequence of reaction