Jitter and Decision-level Noise Separation in A/D Converters

Gaussian aperture jitter leads to a reduced SNR of A/D converters. Also other noise sources, faults and nonlinearities affect the digital output signal. A measurement setup for a new off-chip diagnosis method, which systematically separates the jitter-induced errors from the errors caused by these other factors, is described. Deterministic errors are removed via a subtracting technique. High-level ADC simulations and measurements have been carried out to determine relations between the size of the jitter or decision-level noise and the remaining random errors. By carrying out two tests at two different input frequencies and using the simulation results, errors induced by decision-level noise can be remove

El partenariado en aprendizaje-servicio de la Universidad Católica Australiana y la Universidad DePaul (Chicago)

Aquest article explica el partenariat en aprenentatge servei entre la Universitat Catòlica d'Austràlia i la Universitat DePaul (Chicago) i com aquesta associació ha enriquit l'aprenentatge servei per a ambdues institucions. Mitjançant una metodologia d'estudi de cas, explorem com dues grans institucions catòliques d'educació superior amb missions similars però diferents s'han associat per conèixer els seus enfocaments i contextos. Des del 2018, les dues universitats s'han reunit per discutir els seus programes i explorar oportunitats de col·laboració. Aquestes discussions han donat lloc a noves interpretacions i traduccions de la terminologia pedagògica en contextos australians i nord-americans i a la identificació de com la coherència de la missió pot informar les associacions entre les institucions catòliques d'educació superior. L'associació també ha donat lloc a col·laboracions contínues que han impulsat la missió de l'aprenentatge servei i la seva institucionalització a les dues universitats. L’article conclou reflexionant sobre el valor de les associacions entre les institucions catòliques d'educació superior a través de les fronteres nacionals i el valor d'explorar mútuament la missió, els principis i la pràctica mentre es busca una major institucionalització de l'aprenentatge servei. És a dir, aprenentatge servei en benefici mutu i per a la transformació de la comunitat i la universitat.In this paper, we report on the service-learning partnership between Australian Catholic University and DePaul University (Chicago) and how this partnership has enriched the scholarship of service-learning for both institutions. Using a case study methodology, we explore how two large Catholic Higher Education Institutions (CHEIs) with similar, yet distinct missions have partnered to learn about each other’s approaches and contexts. Since 2018, the SteansCenter for Community-Based Service-learning and Community Service Studies (DePaul) and ACU Engagement, the central agency responsible for supporting the extensive service-learning program at ACU, have met to discuss their programs and explore opportunities for collaboration. These discussions have led to new understandings and translations in the pedagogical terminology across Australian and US contexts and the identification of how mission coherence can inform partnerships between CHEIs. The partnership has also led to ongoing collaborations that have furthered the service-learning mission and institutionalisation of both universities. The paper concludes by reflecting upon the value of partnerships between CHEIs across national boundaries and the value of mutually exploring mission, principles, and practice as the field seeks further institutionalisation of service-learning. That is, service-learning for the mutual benefit and transformation of the community and university.Este artículo explica la relación de partenariado de aprendizaje-servicio entre la Universidad Católica de Australia y la Universidad DePaul (Chicago) y cómo esta asociación ha enriquecido el aprendizaje servicio para ambas instituciones. Mediante una metodología de estudio de caso, exploramos cómo dos grandes instituciones católicas de educación superior con misiones similares pero diferentes se han asociado para conocer sus enfoques y contextos. Desde 2018, ambas universidades se han reunido para discutir sus programas y explorar oportunidades de colaboración. Estas discusiones han dado lugar a nuevas interpretaciones y traducciones de la terminología pedagógica en contextos australianos y estadounidenses y a la identificación de cómo la coherencia de la misión puede informar a las asociaciones entre las instituciones católicas de educación superior. La asociación también ha dado lugar a colaboraciones continuas que han impulsado la misión del aprendizaje-servicio y su institucionalización en ambas universidades. El artículo concluye reflexionando sobre el valor de las asociaciones entre las instituciones católicas de educación superior a través de las fronteras nacionales y el valor de explorar mutuamente la misión, principios y práctica mientras se busca una mayor institucionalización del aprendizaje-servicio. Es decir, aprendizaje-servicio en beneficio mutuo y para la transformación de la comunidad y la universidad

Meizothrombin formation during factor Xa-catalyzed prothrombin activation:Formation in a purified system and in plasma

Meizothrombin and thrombin formation were quantitated during factor Xa-catalyzed activation of human prothrombin in reaction systems containing purified proteins and in plasma. In the purified system considerable amounts of meizothrombin accumulated when prothrombin was activated by factor Xa (with or without accessory components) under initial steady state conditions. The ratio of the rates of meizothrombin and thrombin formation was not influenced by variation of the pH, temperature, or ionic strength of the reaction medium. When 2-mu-M prothrombin was activated by the complete prothrombinase complex (factor Xa, factor Va, Ca2+, and phospholipid) 80-90% of the initially formed reaction product was meizothrombin. Lowering the prothrombin concentration from 2 to 0.03-mu-M caused a gradual decrease in the ratio of meizothrombin/thrombin formation from 5 to 0.6. When the phosphatidylserine content of the phospholipid vesicles was varied between 20 and 1 mol% and prothrombin activation was analyzed at 2-mu-M prothrombin the relative amount of meizothrombin formed decreased from 85 to 55%. With platelets, cephalin, or thromboplastin as procoagulant lipid, thrombin was the major reaction product and only 30-40% of the activation product was meizothrombin. We also analyzed complete time courses of prothrombin activation both with purified proteins and in plasma. In reaction systems with purified proteins substantial amounts of meizothrombin accumulated under a wide variety of experimental conditions. However, little or no meizothrombin was detected in plasma in which coagulation was initiated via the extrinsic pathway with thromboplastin or via the intrinsic pathway with kaolin plus phospholipid (cephalin, platelets, or phosphatidylserine-containing vesicles). Thus, thrombin was the only active prothrombin activation product that accumulated during ex vivo coagulation experiments in plasma

Activity and Movement Patterns of Polar Bears Inhabiting Consolidated versus Active Pack Ice

We investigated the influence of ice conditions on activity and movement patterns of polar bears in the Canadian-West Greenland Arctic. We used radiotelemetry data gathered over 11 years (1989-99) from 160 adult female polar bears to test for differences in movement and activity of bears inhabiting active ice and consolidated ice. Bears inhabiting active ice moved more than those inhabiting consolidated ice (12 versus 8 km/day), but their activity throughout the year did not differ (bears of both groups were active for 21% of the day). Differences in activity and movement of bears in the two study areas appeared to be related to differences in predominant ice conditions and presumed prey availability. Seals, particularly juveniles, are most plentiful in spring and summer, when polar bears moved more and were most active. During winter, when juvenile seals were less available in consolidated ice areas, bears in that habitat were less active and moved less than bears in active ice areas. Polar bears have evolved flexible patterns of seasonal activity, movements, and facultative den use as adaptations to different sea-ice environments.On a étudié l'influence des conditions de glace sur le régime de l'activité et du déplacement de l'ours polaire dans l'Arctique canadien de l'ouest du Groenland. On s'est servi de données prélevées par radiomesure sur une période de 11 ans (de 1989 à 1999) portant sur 160 ourses polaires adultes afin de déterminer s'il existe des différences dans le déplacement et l'activité des ourses entre celles qui vivent sur la glace mobile et celles qui vivent sur la glace soudée. Les ourses vivant sur la glace mobile se déplaçaient plus que celles vivant sur la glace soudée (12 km/jour contre 8), mais leur activité tout au long de l'année ne différait pas (les ourses des deux groupes étaient actives 21 p. cent de la journée). Les différences dans l'activité et le déplacement des ourses entre les deux zones d'étude semblaient être reliées à des différences dans les conditions de glace prédominantes et dans la disponibilité présumée des proies. L'abondance des phoques, en particulier les jeunes, atteint son maximum au printemps et en été, au moment où les ourses polaires étaient souvent le plus actives et se déplaçaient le plus. Durant l'hiver, quand les phoques juvéniles étaient moins disponibles dans les zones de glace soudée, les ourses vivant dans cet habitat étaient moins actives et se déplaçaient moins que les ourses vivant dans les zones de glace mobile. L'ourse polaire a développé une certaine flexibilité de comportement dans son activité, son déplacement et son utilisation facultative d'une tanière, pour s'adapter à différents environnements de glace de mer