The Hilbert transform: introduction and applications

The Hilbert transform is introduced from the mathematical point of view with the purpose in mind to use its properties in signal analysis applications. An important relation with the Fourier transform will be introducted and this will be the key for the implementation in digital analysis. Three applications of the Hilbert transforms will be given, including C++ code for the respective implementations and some data analysis simulations. Results will be commented

Memory: tangible decay & growth

What if the objects we had as children grew up with us and showed the decay, alterations, and new growth that occurred to us? Natural sciences focus, in part, on the endless cycle of growth and decay. Through researching this topic, the question of current versus past arose to question how the mind evolves with age. As a ceramic artist, clay offers a memory through touch by taking the shape and form the creator wills it to have while still able to have movement and force of its own through the molecular makeup and processes it goes through in firings. Just like the many factors that create a ceramic piece, people form memories that revolve around sensory activity, the situations they face, and the impact of emotion occurring at that moment. I use clay to understand a tangible way to represent the human memory of objects, stories, and personal history. The art presented in this thesis aims for memories to take up physical space through ceramic sculptures, shifting and altering the way we think about our past. The ceramic pieces incorporate hand-built fungi and draped forms to evoke this sense of decay and growth. Fungi often need an external host to survive on, and when paired with the notion of draping, a way to cover and preserve objects, my pieces become ghostly ceramic shells of objects being altered in an endless cycle. Through this symbolism, I am able to show that while some situations decay from memories, they become hosts for new ideas. In the pages that follow, you will find an in depth discussion of how I use clay to represent memory, decay, and growth. This will occur through three chapters where I talk through my process (encoding), the artist, influences, and theories behind my work (storing), and finally the success, limitations, use, and learning outcomes I achieved (retrieving). To conclude you will find a summary and the next step in my career (altering)

Effect of amino acid supplementation on skeletal muscle during acute immobilization in hospitalized elderly subjects: possible impact on mitochondria

Objective: Older patients are frequently subjected to prolonged hospitalization and extended bed rest, with a negative effect on physical activity and caloric intake. This results in a consistent loss of muscle mass and function, which is associated with functional decline and high mortality. Furthermore, acute muscle disuse can precipitate sarcopenia, defined as the age-dependent loss of muscle mass and function. The aim of this study was to investigate the effect of oral amino acid (AA) supplementation in acute immobilization. We also aimed to characterize the effect and mechanism of the AA mixture in a rodent model of skeletal muscle atrophy, focusing on mitochondrial function. Methods: In the human study, hospitalized older patients (69-87) were included in the control group (n = 50) or were administered 25 g of AA mixture (n = 44) twice daily throughout 7 d of low mobility. We collected data related to length of stay as primary outcome measure. In-hospital mortality, 90-d post-discharge mortality, 90-d post-discharge rehospitalization, and falls also were considered. Moreover, variations of anthropometric measures, body composition and muscle architecture/strength, circulating interleukins, and oxidative stress markers between the beginning and the end of the supplementation period were analyzed as secondary outcomes. In the animal study, C57/Bl6 mice underwent immobilization of one hindlimb by stapling the foot exploiting normal dorsotibial flexion. Age-matched mice that never had their hindlimbs immobilized were used as controls. Sub-groups of mice subjected to the immobilization procedure were administered the AA mixture in drinking water (I+A) and were compared to a placebo group (I+P). After 10 days, muscle function was studied by both endurance running and grip strength tests. Tibialis anterior (TA) muscles were excised and used for mitochondrial isolation. 2 Results: Similar values were reported between the two groups regarding age, body weight, and body mass index. Although no difference in terms of in-hospital, 90-d post-discharge, or overall mortality rate was observed between the two groups, a reduction in length of stay, 90-d post-discharge hospitalization, and falls was observed in the AA supplementation group rather than in controls. Furthermore, the AA mixture limited muscle architecture/strength impairment and circulating oxidative stress, which occurred during hospitalization-related bed rest. The latter data was associated with increased circulating levels of anti-inflammatory cytokines interleukin-4 and -10. In animals, hindlimb immobilization reduced maximal running times and distances, along with limb grip strength; however, the extent of reduction was lower in I+A than I+P mice. Immobilization resulted in TA atrophy, characterized by a reduction in both wet weight and TA/body weight ratio. Interestingly, these alterations were slightly observed in mice treated with the AA mixture. The mitochondrial yield from TA of I+P mice was lower than controls; of note, the mitochondrial yield from TA of I+A animals was similar to controls. AA mixture administration also preserved mitochondrial bioenergetics and oxidative damage in TA muscle, which was disrupted in I+P mice with respect to controls. Conclusions: These results suggest that the AA mixture limits several alterations associated with low mobility in older hospitalized patients, such as length of stay, 90-d post-discharge hospitalization, and falls, preventing the loss of muscle function, as well as the increase of circulating interleukins and oxidative stress markers. Furthermore, this study demonstrates that the AA mixture prevents loss of muscle mass and function in skeletal muscle atrophy by protecting mitochondria. Other than providing a further link between mitochondria and proteostatic maintenance to muscle atrophy, these results encourage further research aimed at targeting mitochondria to treat sarcopenia

Non-Contact Torque Transfer Using Ferrofluid

Gearing systems are a mechanical based systems that allow an input shaft torque to increase or decrease when it is transferred as an output shaft. Although the gearing system is an old creation that holds little mysteries in the current day, the complexities used to adapt it to new applications continues to grow. The invention discussed and researched in this paper goes in depth on how the gearing system was redesigned to accommodate new uses along with making the system more efficient. A gearing system uses a solid surface to surface contact to transfer the torque from input to output. Overtime, the solid contact surface deteriorate due to friction and inefficiencies causing the destruction of the system in order to produce longer lasting gearing system that require less maintenance and reduce the wear within the system, a more efficient and durable process must be implemented. This paper discusses the redesign of the common gearing system referred to as the non-contact torque transfer using ferrofluid. The ferrofluid gearing system was created within the bounds specified by the sponsor, Dr. Nassersharif. It has been designed to outlast other gearing systems, making it appeal to the customer demand through implementing magnets and ferrofluid. Through calculations and physical observations, the ferrofluid gearing system proved to work and the design concept is able to be patented

The mediterranean diet slows down the progression of aging and helps to prevent the onset of frailty: A narrative review

The aging population is rapidly increasing all over the world. This results in significant implications for the planning and provision of health and social care. Aging is physiologically characterized by a decrease in lean mass, bone mineral density and, to a lesser extent, fat mass. The onset of sarcopenia leads to weakness and a further decrease in physical activity. An insufficient protein intake, which we often observe in patients of advanced age, certainly accelerates the progression of sarcopenia. In addition, many other factors (e.g., insulin resistance, impaired protein digestion and absorption of amino acids) reduce the stimulation of muscle protein synthesis in the elderly, even if the protein intake is adequate. Inadequate intake of foods can also cause micronutrient deficiencies that contribute to the development of frailty. We know that a healthy eating style in middle age predisposes to so-called “healthy and successful” aging, which is the condition of the absence of serious chronic diseases or of an important decline in cognitive or physical functions, or mental health. The Mediterranean diet is recognized to be a “healthy food” dietary pattern; high adherence to this dietary pattern is associated with a lower incidence of chronic diseases and lower physical impairment in old age. The aim of our review was to analyze observational studies (cohort and case–control studies) that investigated the effects of following a healthy diet, and especially the effect of adherence to a Mediterranean diet (MD), on the progression of aging and on onset of frailty

Relecture de vocabulaires d’architecture : apport de la complexité des représentations numériques dans la caractérisation de formes architecturales

En articulant terminologie, logique fonctionnelle et logique géométrique, la sémantique d’un élément peut être considérée comme un concept d’architecture à part entière. Non seulement essentielle à la compréhension de l’évolution stylistique dans le temps et dans l’espace, la sémantique architecturale constitue à bien des égards l’un des fondements des théories d’architecture. En se situant à la croisée de la théorie d’architecture, de l’histoire de l’art, voire des pratiques du relevé, les vocabulaires d’architecture offrent des tentatives de normalisation sémantique qui pourraient être rediscutées à la lumière des avancées scientifiques récentes dans le domaine de l’étude du bâti. Cet article vise donc à concilier les enjeux cognitifs propres à l’étude sémantique d’éléments architecturaux et l’exploitation de la donnée massive issue des représentations numériques. Il s’agit donc de croiser la caractérisation géométrique d’un corpus de formes (résultant de l’examen des similarités géométriques partagées par ce corpus) avec la description donnée par quatre vocabulaires d’architecture. L’enjeu est d’observer les points de rencontre mais aussi de tension entre une sémantique proposée par l’histoire de l’art et une sémantique issue d’une observation géométrique fine. En mettant en exergue les contradictions entre les vocabulaires eux-mêmes et le modèle géométrique obtenu, cet article discute l’apport des méthodes d’analyse provenant de l’informatique graphique dans le développement de connaissances architecturales.By articulating terminology, functional logics and geometrical logics, the semantics of an element can be considered as an architectural concept. In many ways, architectural semantics is one of the foundations of architectural theory, essential for understanding stylistic evolutions in time and space. At the crossroads of architectural theory, art history and even survey practices, architectural vocabularies offer efforts to provide semantic standardisation that might be revisited today, in the light of recent scientific advances in the field of the built heritage. This article aims to reconcile the cognitive issues specific to the semantic study of architectural elements and the exploitation of big data resulting from building digitisations. It is necessary to compare the geometrical characterisation of a corpus of elements (resulting from the examination of the geometrical similarities shared by this corpus) with the description given by four architectural vocabularies. The challenge is to observe the encounters, but also the points of tension between a semantics proposed by the history of art and a semantics resulting from fine geometrical observations. By highlighting the contradictions between the vocabularies themselves and the geometric model, this article discusses the contribution of methods of analysis coming from computer graphics for the development of architectural knowledge

The Multifaced Role of Collagen in Cancer Development and Progression

Collagen is a crucial protein in the extracellular matrix (ECM) essential for preserving tissue architecture and supporting crucial cellular functions like proliferation and differentiation. There are twenty-eight identified types of collagen, which are further divided into different subgroups. This protein plays a critical role in regulating tissue homeostasis. However, in solid tumors, the balance can be disrupted, due to an abundance of collagen in the tumor microenvironment, which significantly affects tumor growth, cell invasion, and metastasis. It is important to investigate the specific types of collagens in cancer ECM and their distinct roles in tumor progression to comprehend their unique contribution to tumor behavior. The diverse pathophysiological functions of different collagen types in cancers illustrate collagen's dual roles, offering potential therapeutic options and serving as prognostic markers

Defensive functioning in individuals with depressive disorders: A systematic review and meta-analysis

Background: This systematic review and meta-analysis aimed to address the limited generalizability of studies on defense mechanisms in depression by comparing depressive individuals with non-clinical controls (aim a) and examining changes throughout psychological interventions (aim b) (PROSPERO CRD42023442620). Methods: We followed PRISMA 2020 guidelines, searching PubMed/Web of Science/(EBSCO)PsycINFO until 13/04/2023 for studies evaluating defense mechanisms with measures based on the hierarchical model in depressive patients versus non-clinical controls or throughout psychological intervention. We conducted random-effect meta-analyses for mature defenses/non-mature (neurotic/immature) defenses/overall defensive functioning (ODF), with standardized mean difference (SMD) as outcome measure metric. Meta-regression/subgroup/sensitivity analyses were conducted. Study quality was appraised using the Newcastle-Ottawa Scale (NOS), and certainty of evidence for aim b outcomes was evaluated using GRADE (Grading of Recommendations, Assessment, Development and Evaluations). Results: 18 studies were included (mean NOS score = 5.56). Depressive patients used significantly more nonmature defenses than non-clinical controls (SMD = 0.74; k = 13). Non-clinical controls did not significantly differ in use of mature defenses compared to depressive patients (SMD = 0.33; k = 14). Significant moderators were publication year/NOS score/geographical distribution/mean age for non-mature defenses and NOS score/geographical distribution for mature defenses. Throughout psychological interventions, only ODF significantly increased (SMD = 0.55; k = 2) (GRADE = very low). Limitations: Quality of many studies was medium/sub-optimal, and longitudinal studies were scarce. Conclusion: Individuals with depressive disorders show a high use of non-mature defenses that could be assessed and targeted in psychological interventions, especially in younger patients

Enhancing therapeutic efficacy through degradation of endogenous extracellular matrix in primary breast tumor spheroids

Solid tumors have a complex extracellular matrix (ECM) that significantly affects tumor behavior and response to therapy. Understanding the ECM's role is crucial for advancing cancer research and treatment. This study established an in vitro model using primary cells isolated from a rat breast tumor to generate three-dimensional spheroids. Monolayer cells and spheroid cultures exhibited different protein expression patterns, with primary tumor spheroids presenting an increased level of ECM-related proteins and a more complex extracellular environment. Furthermore, spheroids produce endogenous collagen type I matrix, which is the main component of the tumoral ECM. This matrix is arranged predominantly around the 3D structure, mimicking the conditions of solid tumors. Treatments with recombinant collagenases class II (acting on the linear collagen region) and class I (acting on the 3D-helix region) completely degrade collagen within the spheroid structure. Collagenase pretreatment enhances the accessibility of the anticancer drug doxorubicin to penetrate the core of spheroids and sensitize them to doxorubicin-induced cytotoxicity. Our findings highlight the importance of overcoming drug resistance in breast cancer by targeting the ECM and proposing a novel strategy for improving therapeutic outcomes in solid tumors. By employing a three-dimensional spheroid model, with an endogenous ECM, we can offer more relevant insights into tumor biology and treatment responses