Aux petites échelles, les équilibres physiques sont bouleversés. En particulier, les forces de contact, de friction et d'adhésion deviennent prépondérantes au regard des autres effets, perturbant ainsi la manipulation des entités appartenant au micro-monde.<br />Ce travail apporte une contribution aux techniques de micromanipulation sans contact dans les microsystèmes intégrés. En nous appuyant sur le principe de la lévitation diamagnétique, qui bénéficie très favorablement de la réduction d'échelle, nous supprimons tout contact physique entre les dispositifs et les microparticules manipulées.<br />Ce point clé nous a permis de démontrer, à travers des structures intégrées et/ou prototypes, la faisabilité d'une microfluidique digitale dans l'air et sans contact, et entre autres le confinement, le micropositionnement et l'actionnement sans contact de divers bioparticules. Ces réalisations ouvrent des perspectives intéressantes au développement de microréacteurs biochimiques sans contamination.

Abstract Employee non-compliance with information systems (IS) security procedures is a key concern for organizations. However, even though the importance of having effective IS security training is widely acknowledged by scholars and practitioners, the existing literature does not offer an understanding of the elementary characteristics of IS security training, nor does it explain how these elementary characteristics shape IS security training principles in practice. To this end, this thesis develops a theory that suggests that IS security training has certain elementary characteristics that separate it from other forms of training, and sets a fundamental direction for IS security training practices. Second, the theory defines four pedagogical requirements for designing IS security training approaches. Then it points out that no existing IS security training approaches meet all these requirements. To address these shortcomings, the way in which to design an IS security training approach that meets all these requirements is demonstrated. In this thesis it is also argued that, along with an effective IS security training approach, reasons for employees’ IS security behavior need to be understood. The existing empirical research in the field of employees’ IS security behavior is dominated by theory-verification studies that test well-known theories developed in other fields in the context of IS security. Instead, it is argued that there is a need to focus the investigation on the phenomenon of employees’ compliance itself through an inductive and qualitative approach to complement the existing body of knowledge of this topic. As a result, a framework identifying reasons associated with compliance/non-compliance with security procedures is developed. A particularly interesting finding is that individuals’ violation of IS security procedures depends on the type of violation. Besides advancing a meta-theory for IS security training and developing the theoretical framework that points out reasons for employees’ IS security behavior, the thesis provides a future research agenda for IS security training and behavior. For practitioners, this thesis points out the limitations of the previous IS security training approaches and reasons for IS security behavior and, based on these observations, offers principles for designing effective IS security training approaches in practice. / Tiivistelmä Yhtenä keskeisenä ongelmana organisaatioissa pidetään sitä, että työntekijät laiminlyövät organisaation tietoturvakäytäntöjä. Vaikka tutkijat ja organisaatiot ovat tunnistaneet tietoturvakoulutuksen tärkeyden, olemassa oleva kirjallisuus ei tuo esiin tietoturvakoulutuksen perusominaisuuksia ja niiden asettamia vaatimuksia käytännön tietoturvakoulutukselle. Tässä väitöskirjassa kehitetään kolmitasoinen meta-teoria, joka huomioi nämä aikaisemmasta tietoturvakoulutusta käsittelevästä kirjallisuudesta puuttuvat kysymykset. Teorian ensimmäisellä tasolla määritellään tietoturvakoulutuksen perusominaisuudet, jotka erottavat sen muista koulutusmuodoista ja ohjaavat tietoturvakoulutuksen toteuttamista käytännössä. Teorian toisella tasolla määritellään neljä pedagogista vaatimusta tietoturvakoulutuksen suunnitteluun. Lisäksi kirjallisuusanalyysin perusteella osoitetaan, että olemassa oleva tietoturvakoulutusta käsittelevä kirjallisuus ei täytä kaikkia näitä vaatimuksia. Teorian kolmannella tasolla esitetään käytännön esimerkki siitä, kuinka tietoturvakoulutus voi täyttää tutkimuksessa määritellyt pedagogiset vaatimukset. Väitöskirjassa esitetään myös, että tehokkaan koulutusmenetelmän lisäksi on tärkeää ymmärtää työntekijöiden tietoturvakäyttäytymistä. Aikaisemmin tällä alueella on pääasiassa testattu muiden tieteenalojen teorioita tietoturvakontekstissa. Tässä väitöskirjassa sen sijaan tarkastellaan työntekijöiden tietoturvakäyttäytymisen syitä induktiivisen ja laadullisen tutkimusmenetelmän avulla. Tutkimuksen tuloksena kehitetään teoreettinen viitekehys, jonka avulla analysoidaan työntekijöiden tietoturvakäyttäytymistä. Tutkimuksen päätuloksena osoitetaan, kuinka tietoturvakäyttäytymiseen syyt eroavat rikkomustyypeittäin. Tietoturvakoulutuksen suunnittelua tukevan meta-teorian ja työntekijöiden tietoturvakäyttäytymistä selittävän teoreettisen viitekehyksen lisäksi väitöskirjassa esitetään uusia näkökulmia tietoturvakoulutuksen ja tietoturvakäyttäytymisen tutkimukselle. Käytännön tietoturva-ammattilaisille väitöskirja selventää olemassa olevien tietoturvakoulutuksen lähestymistapojen puutteita ja syitä työntekijöiden tietoturvakäyttäytymiselle. Näihin havaintoihin perustuen väitöskirjassa esitetään tekijöitä, joita tietoturvakoulutuksessa tulisi käytännössä ottaa huomioon.

Afin de développer une économie basée sur l'hydrogène, il est souhaitable de pouvoir le produire à partir de biogaz (CH4 and CO2) ou de gaz à effet de serre (GES). Le reformage à sec (DRM) et le reformage oxydant du méthane (ODRM) sont des voies prometteuses pour produire H2 et CO à partir des GES et suscitent une grande attention en raison de préoccupations environnementales. Ces réactions ont été étudiées à basse température (600 -700 ° C) sur des oxydes mixtes CeNiX(AlZ)OY, NiXMg2AlOY, et des catalyseurs supportés Ni/SBA-15. Diverses techniques physico-chimiques ont été utilisées pour caractériser les catalyseurs, tels que DRX, XPS, TPR et Raman. L’influence de différents paramètres a été examinée, telles que la température de réaction, le prétraitement sous H2, la teneur en Ni, la masse de catalyseur et les concentrations en réactifs. En particulier, les réactions ont été étudiées à 600 °C, sans dilution des réactifs et sur 10 mg de catalyseur. Les meilleures activités catalytiques et sélectivités sont obtenues sur des catalyseurs partiellement réduits à température appropriée. L'addition d'O2 augmente la conversion du CH4 mais diminue la conversion du CO2, et O2/CH4 =0,3 apparaît comme la condition optimisée en raison de l'activité et de la sélectivité élevées et de la faible formation de carbone. Enfin, un site actif impliquant des espèces Ni en interaction forte avec d'autres cations est proposé. Il est obtenu sur un catalyseur partiellement réduit formé pendant le traitement in situ sous H2 ou sous flux de CH4, il implique des lacunes anioniques, des espèces O2- et des cations / In order to develop a sustainable hydrogen economy, it is desirable to produce hydrogen from biogas (CH4 and CO2) or greenhouses gases (GHG). Dry reforming (DRM) and oxidative dry reforming of methane (ODRM) are promising routes to produce H2 and CO from GHG and have received much attention due environment concerns. Herein, these reactions were studied at low temperatures (600 -700 °C) over CeNiX(AlZ)OY, NiXMg2AlOY mixed oxides and Ni/SBA-15 supported catalysts. Various physico-chemical techniques were employed to characterize the catalysts, such as XRD, XPS, H2-TPR and Raman. The influences of different parameters were examined, such as reaction temperature, pretreatment in H2, Ni content, mass of catalyst and reactants concentration, in particular, at 600°C in harsh conditions (feed gases without dilution) on low mass of catalyst (10 mg). The best catalytic activity and selectivity are obtained on partially reduced catalysts at appropriate temperature. The addition of O2 increases CH4 conversion but decreases CO2 conversion, and O2/CH4 = 0.3 could be the optimized condition due to high activity, selectivity and low carbon formation. Finally, an active site involving Ni species in close interactions with other cations is proposed. It is related to a partially reduced catalyst involving anionic vacancies, O2- species, and cations, which is formed during the in situ H2 treatment or CH4 flow

Το θέμα της κατασκευής ενός συστήματος αναγνώρισης προτύπων για τα ηχητικά σήματα ενός ανθρώπου που κοιμάται είναι ένα από τα ανοιχτά ζητήματα της Βιοιατρικής. Στην παρούσα διπλωματική εξετάζουμε την εξαγωγή ερμηνεύσιμων σημάτων που αντιστοιχούν στον καρδιακό ρυθμό, την αναπνοή και το ροχαλητό. Χρησιμοποιούμε μεθόδους Ανάλυσης σε Ανεξάρτητες Συνιστώσες και μεθόδους Τυφλού Διαχωρισμού που εκμεταλεύονται Στατιστικές Δεύτερης Τάξης. Συμπεραίνουμε ότι οι δεύτερες είναι οι πλέον κατάλληλες όταν συνοδεύονται από ένα στάδιο προεπεξεργασίας που αφορά ανάλυση σε ζώνες συχνοτήτων. / The design of a non-intrusive Pattern Recognition System to estimate the sleep sounds is an open problem of Bioengineering. We use recordings from body-sensors to estimate the heart beat, the breathing and the snoring. In this thesis we examine the effectiveness of Independent Component Analysis for this Blind Source Separation Problem and we compare it with methods that perform Source Separation using Second Order Statistics. We take into account the temporal structure of the sources as well as the presence of noise. Our system is greatly improved by a preprocessing stage of targeted subband decomposition which uses a priori knowledge about the sources. We propose an efficient solution to this problem which is confirmed by medical data.

Proefschrift Universiteit Maastricht. / Met lit. opg. - Met samenvatting in het Nederlands.

Fragestellung: Sowohl die Childhood Group der International Obesity Task Force (IOTF) als auch die European Childhood Obesity Group (ECOG) empfehlen den Body-mass-Index als Beurteilungskriterium für Übergewicht und Adipositas bei Kindern und Jugendlichen. Im Erwachsenenalter erfolgt die Definition von Übergewicht und Adipositas anhand fester Grenzwerte, bei der Beurteilung von Kindern und Jugendlichen müssen die alters- und geschlechtsspezifischen Veränderungen des BMI berücksichtigt werden. Methode: Unter Heranziehung von 17 bereits durchgeführten Untersuchungen aus verschiedenen Regionen Deutschlands wurden BMI-Perzentile für Kinder und Jugendliche erstellt. Die Berechnung der Perzentile basiert auf den Körperhöhen- und Körpergewichtsdaten von 17.147 Jungen und 17.275 Mädchen im Alter von 0–18 Jahren. Ergebnisse und Schlussfolgerung: Die vorgestellten Perzentile sollten als Referenz für deutsche Kinder und Jugendliche angewendet werden. Die Arbeitsgemeinschaft „Adipositas im Kindes- und Jugendalter“ (AGA) hat in ihren Leitlinien die Anwendung der hier vorgestellten 90. und 97. Perzentile zur Definition von Übergewicht und Adipositas empfohlen. / Objectives: Both the Childhood Group of the International Obesity Task Force (IOTF) and the European Childhood Obesity Group (ECOG) recommend to use the body mass index (BMI = weight in kilograms/height in meter2) to evaluate overweight and obesity in children and adolescents. Whereas it is customary with adults to use fixed cut off points to define overweight and obesity, in children and adolescents age and sex specific developmental changes in BMI need to be addressed, which are due to physiological alterations of fat mass. Method: Because a national reference population for children and adolescents does not exist in Germany, a BMI reference data set was compiled. Therefore measurements of height and weight from 17 different regional studies including 17147 boys and 17275 girls aged 0 to 18 years were used. Results and conclusions: We recommend the use of the presented percentiles as reference to asses under- and overweight (obesity) in German children and adolescents. In the guidelines of the “Arbeitsgruppe Adipositas im Kindes- und Jugendalter”(AGA) the 90th and 97th BMI percentiles as calculated in this reference population are proposed as cut-off points for the definition of overweight and obesity in German children and adolescents.

Fragestellung: Sowohl die Childhood Group der International Obesity Task Force (IOTF) als auch die European Childhood Obesity Group (ECOG) empfehlen den Body-mass-Index als Beurteilungskriterium für Übergewicht und Adipositas bei Kindern und Jugendlichen. Im Erwachsenenalter erfolgt die Definition von Übergewicht und Adipositas anhand fester Grenzwerte, bei der Beurteilung von Kindern und Jugendlichen müssen die alters- und geschlechtsspezifischen Veränderungen des BMI berücksichtigt werden. Methode: Unter Heranziehung von 17 bereits durchgeführten Untersuchungen aus verschiedenen Regionen Deutschlands wurden BMI-Perzentile für Kinder und Jugendliche erstellt. Die Berechnung der Perzentile basiert auf den Körperhöhen- und Körpergewichtsdaten von 17.147 Jungen und 17.275 Mädchen im Alter von 0–18 Jahren. Ergebnisse und Schlussfolgerung: Die vorgestellten Perzentile sollten als Referenz für deutsche Kinder und Jugendliche angewendet werden. Die Arbeitsgemeinschaft „Adipositas im Kindes- und Jugendalter“ (AGA) hat in ihren Leitlinien die Anwendung der hier vorgestellten 90. und 97. Perzentile zur Definition von Übergewicht und Adipositas empfohlen. / Objectives: Both the Childhood Group of the International Obesity Task Force (IOTF) and the European Childhood Obesity Group (ECOG) recommend to use the body mass index (BMI = weight in kilograms/height in meter2) to evaluate overweight and obesity in children and adolescents. Whereas it is customary with adults to use fixed cut off points to define overweight and obesity, in children and adolescents age and sex specific developmental changes in BMI need to be addressed, which are due to physiological alterations of fat mass. Method: Because a national reference population for children and adolescents does not exist in Germany, a BMI reference data set was compiled. Therefore measurements of height and weight from 17 different regional studies including 17147 boys and 17275 girls aged 0 to 18 years were used. Results and conclusions: We recommend the use of the presented percentiles as reference to asses under- and overweight (obesity) in German children and adolescents. In the guidelines of the “Arbeitsgruppe Adipositas im Kindes- und Jugendalter”(AGA) the 90th and 97th BMI percentiles as calculated in this reference population are proposed as cut-off points for the definition of overweight and obesity in German children and adolescents.

No description available.

<div>Planetary rings are, and have been, a common feature throughout the solar system.</div><div>Rings have been observed orbiting each of the giant planets, several Trans-Neptunian Objects, and debris rings are thought to have orbited both Earth and Mars.</div><div>The bright, massive planetary rings orbiting Saturn have been observed for centuries, and the Cassini Mission has given researchers a recent and extensive closeup view of these rings.</div><div>The Saturn ring system has served as a natural laboratory for scientists to understand the dynamics of planetary ring systems, as well as their influence on satellites orbiting nearby.</div><div>Researchers have shown that planetary ring systems and nearby satellites can be tightly-coupled systems.</div><div><br></div><div>In this work, I discuss the physics which dominate the dynamical evolution of planetary ring systems, as well as the interactions with any nearby satellites.</div><div>Many of these dynamics have been incorporated into a one-dimensional mixed Eulerian-Lagrangian numerical model that I call "RING-MOONS," to simulate the long-term evolution of tightly coupled satellite-ring systems.</div><div>In developing RING-MOONS, I have discovered that there are three evolution regimes for tightly-coupled satellite-ring systems which I designate as the "Boomerang," "Torque-Dependent," and "Slingshot" regimes.</div><div>Each regime may be defined using the rotation period of the primary body and the bulk density of the ring material.</div><div><br></div><div>The slow rotation period of Mars places it in the Boomerang regime.</div><div>I hypothesize that a giant impact with Mars ejected material into orbit, forming a debris ring around the planet.</div><div>Using RING-MOONS, I demonstrate how Lindblad torques cause satellites which form at the edge of the ring to initially migrate away from the ring, but over time as the mass of the ring decreases, tidal torques always cause the satellites to migrate inwards.</div><div>Assuming the satellites rapidly tidally disrupt upon migrating to the rigid Roche limit, a new ring is formed.</div><div>I show that debris material cycles between orbiting Mars as a planetary ring, or as discrete satellites, and that Phobos may be a product of a repeated satellite-ring cycle.</div><div>Uranus, which has a faster rotation rate falls within the Torque-Dependent regime.</div><div>Hypothesizing that a massive ring once orbited Uranus, I use RING-MOONS to demonstrate how the satellite Miranda may have formed from such a ring, and migrated outwards to its current orbit, but that any other satellites would have migrated inwards overtime.</div><div><br></div><div>Lastly, I examine Trans-Neptunian Objects (TNOs) in binary systems.</div><div>Tidal torques exerted on each body can decrease the mutual semi-major axis of the system.</div><div>I outline the conditions for which a fully synchronous system may experience a complete decay of the mutual orbit due to tidal torques.</div><div>As the semi-major axis decreases, it is possible for the smaller of the two bodies to shed mass before coming into contact with the more massive to form a contact binary.</div><div>I hypothesize that Chariklo and Chiron are contact binaries that formed via the tidal collapse of a binary TNOs system, and demonstrate how mass shedding may have occurred to form the rings observed today.</div>

Lungs donated after cardiac death (DCD) are an underutilized resource for a dwindling donor lung transplant pool. Our study investigates the potential of a novel preservation solution, Somah, to better preserve statically stored DCD lungs, for an extended time period, when compared to low-potassium dextran solution (LPD). We hypothesize that Somah is a metabolically superior organ preservation solution for hypothermic statically stored porcine DCD lungs, possibly improving lung transplant outcomes. Porcine DCD lungs (n = 3 per group) were flushed with and submerged in cold preservation solution. The lungs were stored up to 12 h, and samples were taken from lung tissue and the preservation medium throughout. Metabolomic and redox potential were analyzed using high performance liquid chromatography, mass spectrometry, and RedoxSYS (R), comparing substrate and pathway utilization in both preservation solutions. Glutathione reduction was seen in Somah but not in LPD during preservation. Carnitine, carnosine, and n-acetylcarnosine levels were elevated in the Somah medium compared with LPD throughout. Biopsies of Somah exposed lungs demonstrated similar trends after 2 h, up to 12 h. Adenosine gradually decreased in Somah medium over 12 h, but not in LPD. An inversely proportional increase in inosine was found in Somah. Higher oxidative stress levels were measured in LPD. Our study suggests suboptimal metabolic preservation in lungs stored in LPD. LPD had poor antioxidant potential, cytoprotection, and an insufficient redox potential. These findings may have immediate clinical implications for human organs; however, further investigation is needed to evaluate DCD lung preservation in Somah as a viable option for transplant.