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Modern radio astronomy’s demand for high sensitivity and wide fields of view is met through innovations that reduce receiver system noise temperatures and integrate technology supporting parallel processing and larger instantaneous bandwidths. The advanced L-band phased array camera for astronomy (ALPACA) is a fully cryogenic 69 dual-polarized dipole PAF and digital beamformer back end for the Green Bank Telescope. This instrument will form 40 dual-polarized beams yielding a 0.35 sq. deg field of view on the sky with a 305.2 MHz processing bandwidth. The target system noise temperature is 27 K. A structured technique to map critically sampled and oversampled polyphase filter banks (PFBs) onto a systolic array for implementation on a field programmable gate array (FPGA) is shown. This method provides unique insights into the operation of these algorithms. A case study for an oversampled PFB operating at 666.67 Msps shows that these designs effectively utilize FPGA resources, maintain high-throughput, and are flexible solutions for varied application requirements. A new class of FPGA, the Radio Frequency System-on-Chip (RFSoC), is integrated as a full-functioning software-defined hardware platform in an open-source signal processing toolchain. This provides astronomers with essential hardware for contemporary scientific research. The demonstration for an experimental technique for measuring antenna radiation efficiency using the antenna Y factor method is presented. The noise contribution of the ALPACA dipole when operating at cryogenic temperatures is estimated. Our findings show that the antenna is expected to contribute less than 1 K to the instrument’s overall system noise temperature. Research contributions of this work are: the integration of new high-performance digital hardware in radio astronomical PAF digital back ends, an open-source RFSoC signal processing development toolchain, an oversampled PFB using an FPAG-based systolic array design, and estimating the cryogenic noise temperature of an ALPACA dipole from its radiation efficiency.

Résumé: Mise en contexte : Les infarctus antérieurs avec élévation du segment ST (IMAEST) causent fréquemment une dysfonction ventriculaire gauche. Une diminution de la fraction d’éjection du ventricule gauche (FeVG) est associée à une augmentation du risque d’accident vasculaire cérébral (AVC). Les lignes directrices recommandaient jusqu’à récemment (Classe I, niveau d’évidence C) l’anticoagulation des patients qui, après un IMAEST, étaient jugés à haut risque d’embolie systémique tels que les infarctus étendus ou de la paroi antérieure. Généralement, ces patients reçoivent une anticoagulation d’une durée de trois mois en combinaison avec une double thérapie antiplaquettaire pour au moins quatre semaines. Si les anomalies régionales de la contractilité se normalisaient avant trois mois, la durée de l’anticoagulation pourrait potentiellement être écourtée. La cinétique de récupération des infarctus antérieurs revascularisés par angioplastie primaire est mal décrite. Objectif : Chez des patients ayant subi un IMAEST de la paroi antérieure revascularisés par angioplastie primaire, évaluer si la FeVG et la récupération de l’akinésie antérieure et apicale est différente à un mois et trois mois post infarctus. Méthode : De façon prospective, nous avons recruté 42 patients présentant une FEVG de 45% ou moins et une akinésie de la paroi antérieure ou apicale lors de l’échocardiographie réalisée 48 heures post IMAEST. Des échocardiographies étaient obtenues à un mois et trois mois post IMAEST. Chaque échocardiographie était interprétée par deux cardiologues indépendants à l’aveugle des données cliniques. Résultats : Lorsque comparée à la FeVG à 48 heures post IMAEST, la FeVG à un mois s’était déjà améliorée de façon significative (38% à 42%, p=0.03). Il n’y avait pas d’amélioration significative supplémentaire entre un mois et trois mois (42% à 44%, p=NS). La dynamique des segments apicaux et antérieurs s’améliorait de façon significative entre 48 heures et un mois, mais aussi entre un mois et trois mois. Conclusion : Vu l’amélioration significative de la FeVG et de l’akinésie antérieure et apicale à un mois post IMAEST, il pourrait être justifié de ré-évaluer la FeVG plus précocement chez les patients anticoagulés pour cette indication afin de minimiser la durée de l’anticoagulation et le risque de saignement qui y est associé. / Abstract: Background: Anterior ST-elevation myocardial infarction (STEMI) frequently causes left ventricular dysfunction. Worsening left ventricular ejection fraction (LVEF) is associated a higher stroke rate. Prior guidelines recommended anticoagulation for patients after STEMI who are at high risk for systemic emboli and specified that large or anterior myocardial infarctions (MI) are part of that group (Class I, level of Evidence C). The 2013 Guidelines made it a Class IIB recommendation and restricted the recommendation to those with anterior or apical akinesia and dyskinesia. These patients are usually given three months of anticoagulation. If the regional wall motion abnormalities were to normalize earlier, the duration of anticoagulation could be shortened. However, the kinetics of recovery after an anterior MI revascularized with primary percutaneous intervention are not well described. Objective: To evaluate if LVEF and apical and anterior akinesia recuperation is different at one month and three months after STEMI in patients treated with primary percutaneous angioplasty. Methods: We prospectively recruited 42 patients who had a LVEF of 45% or less and apical or anterior akinesia on echocardiography at 48 hours post STEMI. Echocardiography was repeated one month and three months post STEMI. Each echocardiogram was interpreted by two different cardiologists who were blinded to clinical information. Results: When compared to 48 hours post STEMI, LVEF at one month had already improved significantly (38% to 42%, p=0.03) and there was no further significant improvement at three months (44%, p=NS). Anterior and apical akinesia decreased significantly between the 48 hours and one month echocardiograms, but also between one month and three months. Conclusion: Given that LVEF and anterior/apical akinesia improve significantly within the first post STEMI month, it may be worth re-evaluating the LVEF earlier in patients in whom the decision was made to start anticoagulation for that indication in order to minimize the duration of anti-coagulation and the associated bleeding risk.

<p>Teza istražuje mogućnost kori&scaron;ćenja kopule u finoj analizi međusobne zavisnosti kardiovaskularnih signala. U tu svrhu kori&scaron;ćene su različite GoF (Goodness of Fit) tehnike i matematički alati bazirani na kopuli. Predložena metoda određuje nivo zavisnosti kao funkciju vremenskog ka&scaron;njenja signala pulsnog intervala u odnosu na signal sistoličkog krvnog pritiska i omogućuje uvid u mehanizme otkucaj-po-otkucaj regulacije krvnog pritiska. Farmakolo&scaron;ka validacija je izvedena administracijom lekova koji inhibiraju autonomni nervni sistem, pri čemu su dobijeni rezultati imali jasan fiziolo&scaron;ki odziv.</p> / <p>The thesis investigates a possibility to apply a copula method for a more refined analysis of mutual dependency of cardiovascular signals. Different GoF (Goodness of Fit) techniques and mathematical tools based on copula are applied to prove this possibility. Proposed method determines the level of dependency of the pulse interval response in respect to the systolic blood pressure for different time lags and provides further insight into the beat-to-beat regulation of blood pressure. Pharmacological validation of the method was performed by administration of autonomic blockers drugs, as the obtained copula response was in accordance with the physiological interpretation.</p>

Background The prevalence and incidence of stroke are known to increase with age, which, combined with demographic change, means that very old patients with stroke are a growing patient group. Risk factors for incident stroke among very old people have not been widely investigated. The impact of depression on mortality in very old people who have had a stroke also remains unclear.  The aim of this thesis was to investigate the risk factors for incident stroke, the epidemiology of stroke and depression, and the consequences of having had a stroke regarding the risk of depression and mortality among very old people. Methods A randomly selected half of 85-, all 90-, and all ≥95-year-olds in certain municipalities in Västerbotten County, Sweden, and Pohjanmaa County, Finland were targeted in a population-based cohort study from 2000-2012. The 65-, 70-, 75-, and 80-year-olds in all the rural and random samples from the urban municipalities in the same counties were furthermore targeted in a survey in 2010. In the cohort study patients were assessed in their homes, by means of the 15-item Geriatric Depression Scale (GDS-15) and other assessment scales, as well as blood pressure measurements, several physical tests, and a review of medical diagnoses appearing in the medical charts. Incident stroke data were collected from medical charts guided by hospital registry records, cause of death records, and reassessments after 5 years. Depression was defined as a GDS-15 score ≥5. A clinical definition of all depressive disorders, based on assessment scale scores and review of medical charts was also used. A specialist in geriatric medicine evaluated the diagnoses. The survey included yes/no questions about stroke and depression status, and the 4-item Geriatric Depression Scale. Associations with mortality and incident stroke were tested using Cox proportional-hazard models.  Results In the ≥85-year-olds examined in 2005-2007 (n=601), the stroke prevalence was 21.5%, the prevalence of all depressive disorders was 37.8% and stroke was independently associated with depressive disorders (odds ratio 1.644, p=0.038). The prevalence of depression according to GDS-15 scores was 43.2% in people with stroke compared with 25.0% in people without stroke (p=0.001). However, in ≥85-year-olds examined in Sweden from 2000-2012 (n=955), from all past data collections in the study, depression was not independently associated with incident stroke.  In ≥65-year-olds who responded to a survey in 2010 (n=6098), the stroke prevalence rose with age from 4.7% among the 65- to 11.6% among the 80-year-olds (p&lt;0.001). The prevalence of depression rose from 11.0% among the 65- to 18.1% among the 80-year-olds (p&lt;0.001). In the group with stroke, depression was independently associated with dependence in personal activities of daily living and having a life crisis the preceding year, while in the non-stroke group, depression was independently associated with several additional demographic, social and health factors. In ≥85-year-olds examined in 2005-2007 with valid GDS-15 tests (n=452), having had a stroke was associated with increased 5-year mortality [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.15-2.03]. Having had a stroke and depression was associated with increased 5-year mortality compared with having only stroke (HR 1.90, 95% CI 1.15-3.13), having only depression (HR 1.59, 95% CI 1.03-2.45), and compared with having neither stroke nor depression (HR 2.50, 95% CI 1.69-3.69). Having only stroke without a depression did not increase mortality compared with having neither stroke nor depression. In ≥85-year-olds examined in Sweden from 2000-2012 (n=955), from all past data collections in the study, the stroke incidence was 33.8/1000 person-years during a mean follow-up period of about three years. In a comprehensive multivariate model, atrial fibrillation (HR 1.85, 95% CI 1.07–3.19) and higher systolic blood pressure (SBP; HR 1.19, 95% CI 1.08–1.30 per 10-mmHg increase) were associated with incident stroke overall. In additional multivariate models, diastolic blood pressure (DBP) ≥90 mmHg (HR 2.45, 95% CI 1.47–4.08) and SBP ≥160 mmHg (v. &lt;140 mmHg; HR 2.80, 95% CI 1.53–5.14) were associated with incident stroke. Conclusion The prevalence of both stroke and depression increased with age, and rates were especially high among very old people. Having had a stroke was independently associated with a higher prevalence of depression among very old people, however, depression was not independently associated with a higher incidence of stroke. Having had a stroke was associated with increased all-cause mortality among very old people, but only among those who were also depressed. High SBP (≥160 mmHg), DBP (≥90 mmHg) and atrial fibrillation were the only consistent independent risk factors for incident stroke among very old people. / I västvärlden inklusive Sverige så ökar gruppen av människor som uppnår åldern 80 år eller äldre. Människorna som uppnår denna mycket höga ålder har en hög förekomst av kardiovaskulära riskfaktorer, har ofta flera samtidiga sjukdomar och ofta funktionsnedsättningar. Medicinska behandlingsåtgärder är ofta mindre effektiva och förknippade med biverkningar i åldersgruppen. Stroke är en sjukdom som beror på skada av hjärnvävnad till följd av minskad blodtillhörsel till delar av hjärnan. Det är känt att såväl förekomsten av och insjuknandet i stroke ökar med stigande ålder. Den som drabbas av stroke löper risk att få en bestående funktionsnedsättning och att dö i förtid. En vanlig komplikation efter att ha drabbats av stroke är nedstämdhet eller depression. Vetenskapliga studier om stroke har tidigare negligerat mycket gamla människor, vilket i takt med den pågående demografiska utvecklingen framstått som allt mer orimligt. Det är ej helt klarlagt vilka riskfaktorer som leder till att insjukna med stroke i mycket hög ålder. Överdödligheten förknippad med att drabbas av depression efter stroke är också oklar i åldersgruppen. Det är också oklart vad som skiljer depression efter stroke från depression bland den övriga befolkningen av åldrade människor. Den populations-baserade kohortstudien GErontologisk Regional DAtabas (GERDA) inleddes år 2000 för att kartlägga faktorer förknippade med gott åldrande bland mycket gamla människor. Hälften av 85-åringarna, alla 90-åringar och alla ≥95-åringar i utvalda kommuner i Västerbotten erbjöds att delta i studien. Därefter har återbesök hos tidigare deltagare i sina nya åldersgrupper och rekrytering av nya deltagare genomförts vart femte år. Studien utvidgades med utvalda kommuner i Österbotten, Finland vid den första femårsuppföljningen. Datainsamlingen i studien bestod av demografiska frågor, skattningsskalor, blodtrycksmätning och kognitiva test genomförda vid ett hembesök i deltagarens hem, samt genomgång av journalhandlingar. År 2010 skickades även en enkät ut till 65-, 70-, 75- och 80-åringar i alla kommuner i Västerbotten och Österbotten. Enkäten innehöll frågor om demografi, hälsa, sjukdomar och intressen. Bland deltagarna i kohortstudien bestämdes förekomsten av tidigare stroke baserat på genomgång av journaluppgifter och uppgifter från hembesöken. Förekomsten av depression bestämdes baserat på poängsättning från en validerad skattningsskala för depression, samt baserat på en sammanvägning av journaluppgifter och skattningsskalor. En specialist i geriatrik fattade det slutliga beslutet om diagnoser. Insjuknande i stroke bestämdes baserat på journalgenomgång av individer med stroke-relaterade diagnoskoder i sjukhusregistret, i dödsorsaksregistret eller uppgift om stroke vid femårsuppföljningen i studien. Bland deltagarna i enkätstudien bestämdes förekomsten av tidigare stroke baserat på självrapportering, och förekomsten av depression bestämdes baserat på en sammanvägning av självrapportering och en skattningsskala för depression.  Förekomsten av stroke i enkätstudien steg med ålder, från 4.7% bland 65-åringar till 11.6% bland 80-åringar. Förekomsten av stroke var omkring 20% bland ≥85-åringar, med minimal variation mellan 85-, 90- och ≥95-åringar. Förekomsten av depression var högre bland dem med stroke jämfört med de övriga deltagarna, både gällande den sammavägda diagnosen och baserat endast på poängsättning. Stroke och sömnproblem var oberoende associerade med depression. Bland ≥65-åringar i enkätstudien var funktionsnedsättning och genomgången livskris associerade med depression hos dem med en tidigare stroke. Bland deltagare utan stroke var ett antal ytterligare externa faktorer, inklusive subjektiv upplevelse av dålig ekonomi och att inte ha någon att anförtro sig till, associerade med depression. Både stroke och depression var associerade med ökad dödlighet bland ≥85-åringar. De med stroke utan depression hade en dödlighet i linje med normalbefolkningen utan stroke eller depression. Förekomsten av samtidig stroke och depression var associerad med högre dödlighet än normalbefolkningen, jämfört med dem med enbart stroke eller enbart depression. Högt systoliskt blodtryck (≥160 mmHg), högt diastoliskt blodtryck (≥90 mmHg) och förmaksflimmer var oberoende riskfaktorer för att insjukna i stroke bland ≥85-åringarna. Sambandet mellan blodtryck och strokerisk försvagades ej hos människor med kognitiv eller funktionell nedsättning. Tidigare stroke, hjärtsvikt, kognitiv nedsättning, näringsbrist, depressiva symtom och låg gånghastighet var också associerade med att insjukna i stroke, men ej oberoende av varandra. Sammanfattningsvis så stiger förekomsten av stroke med åldern och är särskilt hög bland mycket gamla människor. Depression är betydligt vanligare hos mycket gamla människor med stroke, även justerat för störningsfaktorer. Depression är främst associerat med funktions-nedsättning hos människor med stroke, men med ett större antal externa faktorer hos människor utan stroke. Mycket gamla människor med stroke har särskilt hög dödlighet om de samtidigt är deprimerade, men en dödlighet i linje med normalbefolkningen om de inte är deprimerade. Högt systoliskt och diastoliskt blodtryck samt förmaksflimmer är viktiga och behandlingsbara orsaker till att drabbas av stroke i mycket hög ålder.

Soit G un groupe de présentation finie. Un résultat de Gromov affirme l'existence de cycles géométriques réguliers qui représentent une classe d'homologie non nulle h dans le énième groupe d'homologie à coefficients entiers de G, cycles géométriques dont le volume systolique est aussi proche que souhaité du volume systolique de h. Ce théorème, dont aucune démonstration exhaustive n'avait été faite, a servi à obtenir plusieurs résultats importants en géométrie systolique. La première partie de cette thèse est consacrée à une démonstration complète de ce résultat. L'utilisation de ces cycles géométriques réguliers est connue sous le nom de technique de régularisation. Cette technique permet notamment de relier le volume systolique de certaines variétés fermées à d'autres invariants topologiques de ces variétés, tels que les nombres de Betti ou l'entropie minimale. La seconde partie de cette thèse propose d'examiner ces relations, et la mise en oeuvre de la technique de régularisation.La troisième partie est consacrée à trois problèmes liés à la géométrie systolique. Dans un premier temps on s'intéresse à une inégalité concernant les tores pleins plongés dans l'espace tridimensionnel. Puis, on s'intéresse ensuite aux triangulations minimales des surfaces compactes, afin d'obtenir des informations sur le volume systolique de ces surfaces. Enfin, on présente la notion de complexité simpliciale d'un groupe de présentation finie, et ses liens avec la géométrie systolique. / Let G be a finitely presented group. A theorem of Gromov asserts the existence of regular geometric cycles which represent a non null homology class h in the nth homology group with integral coefficients of G, geometric cycles which have a systolic volume as close as desired to the systolic volume of h. This theorem, of which no complete proof has been given, has lead to major results in systolic geometry. The first part of this thesis is devoted to a complete proof of this result.The regularizationtechnique consists in the use of these regular geometric cycles to obtain information about the class $h$. This technique allows to link the systolic volume of some closed manifolds to homotopical invariants of these manifolds, such as the minimal entropy and the Betti numbers. The second part of this thesis proposes to investigate these links.The third part of this thesis is devoted to three problems of systolic geometry. First we are investigating an inequality about embeded tori in $R^3$. Second, we are looking into minimal triangulations of compact surfaces and some information they can provide in systolic geometry. And finally, we are presenting the notion of simplicial complexity of a finitely-presented group and its links with the systolic geometry.

Les auto-tensiomètres (AT) sont parmi les dispositifs les plus utilisés en clinique et à domicile pour la mesure de la pression artérielle (PA). Ces appareils utilisent deux algorithmes heuristiques (Height-Based/HB et Slope-Based/SB) pour déterminer les pressions artérielles systoliques (PAS) et diastoliques (PAD) à partir de l'enregistrement de la pression oscillométrique dans le brassard. La mise sur le marché de ces appareils est actuellement assujettie à la directive 93/42/CE, qui nécessite une étude clinique basée sur une comparaison avec des mesures de la PA par auscultation. Cette méthode, qui consiste à détecter des sons de Korotkoff dans l'artère auscultée, présente l'inconvénient d'être praticien dépendante et engendre une incertitude sur la mesure de la PAS et de la PAD. Il est donc nécessaire de s'assurer de la fiabilité de ces instruments en proposant un dispositif expérimental de référence permettant en outre de pallier l'étude clinique qui s'avère longue et coûteuse. Cette thèse est dédiée à la mise en place de ce dispositif ou chaîne de référence, qui associe un banc d'essai permettant la validation des auto-tensiomètres et une base de données de mesure de PA. Afin de réaliser notre objectif, une étude clinique a été réalisée à l'hôpital Nord de Marseille à l'issue d'un examen de coronarographie. L'étude, réalisée sur 115 patients, compare des mesures de pression invasives (mesures de référence) à des mesures de pression non-invasives : des mesures auscultatoires, des mesures via un auto-tensiomètre commercial et des mesures oscillométriques. Ces dernières ont été réalisées concomitamment avec la PA invasive. / Automated blood pressure (ABP) devices are among the most commonly used devices for diagnosis arterial blood pressure (BP) for clinical and home use. These devices use two heuristic algorithms (Height-Based/HB and Slope-Based/SB) to determine the systolic blood pressure (SBP) and the diastolic blood pressure (DBP) from the recording of an oscillometric pressure signal collected using an inflatable cuff. Currently ABP are in the scope of Directive 93/42/CE, which requires a clinical study based on a comparison of BP measurements using auscultatory method. Unfortunately auscultatory measurements have the disadvantage of the uncertainties related to perception of Korotkoff sounds, leading to an uncertainty of measuring SBP and DBP. Therefore it is necessary to ensure the reliability of these instruments and to propose an experimental reference chain to validate ABP devices without returning to expensive and long clinical campaign. The purpose of this thesis is to create and develop a calibration chain for measuring arterial BP, which is composed of database of arterial BP measurements and a patient simulator for regenerating oscillometric measurements. To achieve our target, a clinical study was conducted at the northern hospital of Marseille (l'hôpital Nord) after a coronary exam. The clinical study of 115 patients compares invasive blood pressure measurements (reference measurements) and non-invasive blood pressure measurements: auscultatory measurements, measurements using a commercial automated blood pressure device and oscillometric measurements. The latter were carried out simultaneously with the invasive BP measurements.

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