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The Cell processor is an example of the trade-offs made when designing a mass market power efficient multi-core machine, but the machine-exposing architecture and raw communication mechanisms of Cell are hard to manage for a programmer. Cell's design is simple and causes software complexity to go up in the areas of achieving low threading overhead, good bandwidth efficiency, and load balance. Several attempts have been made to produce efficient and effective programming systems for Cell, but the attempts have been too specialized and thus fall short. We present Jack Rabbit, an efficient thread pool work queue implementation, with load balancing mechanisms and double buffering. Our system incurs low threading overhead, gets good load balance, and achieves bandwidth efficiency. Our system represents a step towards an effective way to program Cell and any similar current or future processors. / text

In this master thesis a small modular sodium-cooled metal-fuelled pool-type fast reactor design, called SPARC - Safe and Passive with Autonomous Reactivity control, has been designed. The long term reactivity changes in the SPARC are managed by implementation of the the Autonomous Reactivity Control (ARC) system, which is the novelty of the design. The overall design is mainly based on the Integral Fast Reactor project (IFR), which experimentally demonstrated the passive safety characteristics of a metal fuelled, sodium-cooled, pool-type reactor system. Whilst mimicking the passive safety features of the IFR, the vision of the SPARC design is a battery type reactor, which can operate with minimum interference from human actors. In this thesis, two reactor examples have been developed which operate using different fuel compositions. One reactor operates on recycled nuclear waste from today's nuclear power plants, and the other reactor operates on enriched uranium. Both reactors have a thermal power of 150 MW, and are meant to operate for 30 years without refuelling. The design was developed using the ADOPT software, and was simulated in Serpent. Using Serpent, criticality analyses were carried out which show that the ARC system is able to control the long term reactivity changes of the reactors.

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Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Variability in the tropical ocean-atmospheric system causes global scale climate anomalies, most evident in the El Niño-Southern Oscillation’s coupled climate feedbacks. Despite being an area of high interest, many questions still remain regarding the west Pacific warm pool’s response to external forcing, particularly its response to increases in anthropogenic greenhouse gases. Paleoclimate reconstructions coupled with model simulations provide insight into the tropical Pacific’s role in past climate variability necessary to the development of robust climate projections. Most paleoclimate records, however, still lack the resolution, length, and chronological control to resolve rapid variability against a background of orbital-scale variations. Here we present stalagmite oxygen isotope (δ18O) reconstructions from Gunung Mulu National Park (4oN, 115oE ), in northern Borneo, that provide reproducible centennial-scale records of western Pacific hydrologic variability that are precisely U/Th-dated and continuous throughout most of the late Pleistocene (0-160 thousand years ago, kybp). The record comprises an entire glacial-interglacial cycle, which allows us to investigate orbital-scale climate forcings and compare two well-dated glacial terminations in the western tropical Pacific. The ice- volume-corrected δ18O records suggest that glacial boundary condtions, which include significantly lower atmospheric carbon dioxide levels, did not drive significant changes in Mulu rainfall δ18O. Similarly, Borneo stalagmite δ18O is poorly correlated to either global sea level shifts or Sunda Shelf areal exposure is not evident. The Borneo record does vary in phase with local mid-fall equatorial insolation, suggesting that precessional forcing may impart a strong influence on hydroclimate variability in the warm pool. This is best illustrated across Glacial Termination II, when the oscillation of equatorial fall insolation is large and out of phase with ice sheet decay. We also use a subset of well-dated, high-resolution stalagmite δ18O records from Mulu to investigate millennial-scale climate variability during Marine Isotope Stages 3-5 (30-100kybp). We find that regional convection likely decreased during the six massive iceberg discharges defined in the North Atlantic sediment records (“Heinrich events”). The inferred drying (increased stalagmite δ18O) during Heinrich events is consistent with a southward shift of the Intertropical Convergence Zone – the dominant paradigm to explain global climate anomalies originating in the north Atlantic (ref). However, any hydrologic variability related to Dansgaad-Oeschgar (D/O) events, millennial-scale sawtooth temperature anomalies of the last glacial period first evident in the Greenland ice records, is notably absent in the stalagmite records. . The Mulu stalagmite record’s absence of D/O signal, however, is in marked contrast to the regional west Pacific marine records and suggests D/O events and Heinrich events may be characterized by fundamentally different climate mechanisms and feedbacks.

Diet and oral supplements comprise two distinct sources of antioxidants known to prevent oxidative stress. Beneficial effects from antioxidants have been seen for patients at risk for type 2 diabetes. The aim of this thesis was to evaluate the positive effects of antioxidants against oxidative stress and DNA damage in type 2 diabetes subjects. We also used antioxidants as tools to determine the mechanisms behind genotoxicity induced by mutagenic pro-oxidative agents in mouse lymphoma cells. Several techniques were used to measure oxidative stress and DNA damage, but the main technique used was alkaline comet assay. The results showed that the fruit and vegetable intake was inversely related to oxidative stress in type 2 diabetes subjects. However, oral supplementary intake of 20 antioxidants did not decrease oxidative stress biomarkers. In studies on mouse lymphoma cells, using the alkaline comet assay, DNA damage was induced by catechol and o-phenylenediamine (OPD), while 4-nitro-o-phenylenediamine (4-NOPD) induced only oxidative damage, showing different mechanisms of action behind the mutagenicity of the compounds. Also, oxidative stress was induced by catechol and 4-NOPD, whereas imbalances in the nucleotide pool were seen after exposure to OPD or 4-NOPD. Addition of antioxidants together with these pro-oxidants showed that β-carotene was able to reduce DNA damage at low concentrations of catechol, but increased DNA damage at high concentration. In comparison, addition of α-tocopherol slightly decreased catechol-induced DNA damage at all concentrations of catechol. However, no effect of α-tocopherol was seen on OPD-or 4-NOPD-induced DNA damage. In conclusion, antioxidants from fruits and vegetables, but not from oral supplements, reduced oxidative stress in type 2 diabetes patients, suggesting fruits and vegetables being a healthier source for antioxidant-intake, as compared to oral supplements. Different mechanisms of action for mutagenic pro-oxidants were shown in mouse lymphoma cells, introducing the nucleotide pool as an interesting target for oxidative stress. Reduction of catechol-induced DNA damage by β-carotene or α-tocopherol was shown, with a pro-oxidative action of β-carotene at high concentration of catechol, Interestingly, α-tocopherol was not able to decrease OPD- or 4-NOPD-induced DNA damage, supporting different mechanisms of action behind the genotoxicity from the three pro-oxidants.

This work explores the connections between the constructed representations of places based on local histories, the processes of tradition reinvention and the strategies of regional development in two Russian regions. This analysis also outlines the context created by the external to the regions influences and the associated with them local conditions.

Bakgrunn: I helsesektorener det mange pleiere som arbeider ufrivillig deltid, noe som gjør at de ikke får forutsigbar inntekt og arbeidstid. En bemanningsenhet kan være et virkemiddel for å redusere omfanget av ufrvillig deltid. Hensikt: Studiens hensikt er å få kunnskap om hvilke faktorer som er viktige for at en bemanningsenhet skal kunne være en god og varig arbeidsplass for pleiereog samtidig gi tjenester av god kvalitet. Metode: Utvalget bestod av 14 pleiere som hadde arbeidet i en bemanningsenhet i syv til atten måneder. Datainnsamlingen ble hovedsakelig foretatt gjennom tre fokusgruppeintervjuer, og datamaterialet ble analysert ved metoden kvalitativ innholdsanalyse. Resultat: Tre kategorier ble identifisert og beskrevet: Organisering og kultur, Helsefremmende arbeidsplasser og Medarbeidernes kvalifikasjoner. Konklusjon: Studien viser at full fast stilling er en grunnleggende forutsetning for å rekruttere ansatte til bemanningsenheter. For å beholde de ansatte, er det viktig med systematisk og strukturert opplæring og vedlikehold og utvikling av kompetanse. Tydelig ledelse som skaper helsefremmende arbeidsplasser ved å legge til rette for mestring, anerkjennelse og tilhørighet er viktig for å beholde pleierne, og for at de skal gi tjenester av god kvalitet. De ansattes mestringsressurser og personlige egenskaper ser ut til å ha en betydning / Background: In healthcare manyc aregivers work part-time involuntarily, resulting in unpredictable income and work schedule. A staffing unit could providean efficient tool for reducingthe scope of involuntary work. Purpose: This study aimed to determine the important factors in supporting a good staffing unit and full-time work for caregivers while simultaneously providing quality services. Method: We recruited 14 caregivers,who had worked ina staffing unit for 7-18 months, to participate inthree focus-group interviews. We reviewed all data using qualitative content analysis. Result: We identified and describedthree categories: organization and culture, health promoting work places, and the qualifications of the employees. Conclusion: Our results show that a full-timeposition is a basic requirement for recruitment to staffing units. Retaining employees requires systematic and structured training as well as skill development and maintenance. Management should promote a healthy workplace by facilitating coping skills and recognizing achievement, ambition, and affiliation. Such promotion ensures careg ivers’ ability to provide quality care. The employees’ coping resources and personal skills appear to be significant. / <p>ISBN 978-91-86739-94-2</p>