1,467 research outputs found

    A Flexible and Fast Event-Driven Simulator for wireless MAC protocols

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    Many multiple-access (MAC) protocols have been or are being proposed for wireless networks. As most of these multiple-access protocols are designed for specific applications (such as telephony) and analyzed accordingly, the analysis results can not always be adapted to situations where each user has a different behavior. Wireless MAC protocols for data communication are not straightforward to analyse. To quickly make a reliable judgement of the usability of a MAC protocol for specific situations, we designed a simulator that makes it simple to implement the protocol and test it in different configurations and with differently behaving users. Our simulator generates a large amount of quantitative performance information that can be processed with standard graph drawing tools and an integrated trace analyze

    Organic carbon compounds associated with deep soil carbon stores

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    Aims Organic carbon has been reported in deep regolithic profiles to depths of tens of metres, but the composition of the carbon compounds is unknown. Methods Residual carbon in the form of non-volatile low molecular weight compounds (LMWC) was characterised in three deep soil profiles to a depth of 19 m under farmland in south-western Australia following extraction with ethyl acetate and analysis by GC/MS. Pyrolysis and off-line thermochemolysis were used to characterise macromolecular organic carbon (MOC) to a depth of 29 m at a fourth site. Results Three compound classes occurred across the three different field locations: (1) terpenes, (2) fatty acids, amides and alcohols, and (3) plant steroids; indicating the influence of input of the past and present vegetation. Compounds related to fatty acids were the predominant residual carbon species in deep soils, and may be derived from plants and microorganisms. Biomarkers such as lignin, polysaccharides, proteins and terpenes at 0–0.1 m implied influences of vegetation, fire events and microorganisms. Pyrolysis found that polysaccharides were distributed mainly from 0 to 0.1 m, while aromatic compounds were consistently detected down to 29 m. Conclusions Carbon was stabilised in the form of aromatic compounds in deep soil, whereas other carbon sources such as cellulose, chitin, and N-containing compounds were confined to the surface soil. LMWC (Z)-docos-13-enamide and bis(6-methylheptyl) phthalate, were the main components throughout the soil profiles representing 53–81% of the LMWC, and were a greater proportion of the organic matter at depths of 18–19 m

    Phase I dose-escalation and pharmacokinetic study of dasatinib in patients with advanced solid tumors

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    PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicity (DLT), and recommended phase II dose of dasatinib in metastatic solid tumors refractory to standard therapies or for which no effective standard therapy exists. <br></br> EXPERIMENTAL DESIGN: In this phase I, open-label, dose-escalation study, patients received 35 to 160 mg of dasatinib twice daily in 28-day cycles either every 12 hours for 5 consecutive days followed by 2 nontreatment days every week (5D2) or as continuous, twice-daily (CDD) dosing. <br></br> RESULTS: Sixty-seven patients were treated (5D2, n = 33; CDD, n = 34). The maximum tolerated doses were 120 mg twice daily 5D2 and 70 mg twice daily CDD. DLTs with 160 mg 5D2 were recurrent grade 2 rash, grade 3 lethargy, and one patient with both grade 3 prolonged bleeding time and grade 3 hypocalcemia; DLTs with 120 mg twice daily CDD were grade 3 nausea, grade 3 fatigue, and one patient with both grade 3 rash and grade 2 proteinuria. The most frequent treatment-related toxicities across all doses were nausea, fatigue, lethargy, anorexia, proteinuria, and diarrhea, with infrequent hematologic toxicities. Pharmacokinetic data indicated rapid absorption, dose proportionality, and lack of drug accumulation. Although no objective tumor responses were seen, durable stable disease was observed in 16% of patients.<br></br> CONCLUSION: Dasatinib was well tolerated in this population, with a safety profile similar to that observed previously in leukemia patients, although with much less hematologic toxicity. Limited, although encouraging, preliminary evidence of clinical activity was observed. Doses of 120 mg twice daily (5D2) or 70 mg twice daily (CDD) are recommended for further studies in patients with solid tumors.<br></br&gt

    Wildlife Harvesting and Sustainable Regional Native Economy in the Hudson and James Bay Lowland, Ontario

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    To assist the Omushkego Cree in planning a community and regional economic development strategy that takes into account the traditional economy, we developed appropriate methodologies to investigate the quantitative importance and economic value of hunting and fishing for the Mushkegowuk region, Hudson and James Bay Lowland. Harvests of wildlife by the 6500 aboriginal residents of eight communities - Moose Factory, Moosonee, New Post, Fort Albany, Kashechewan, Attawapiskat, Peawanuck and Fort Severn - were estimated by means of a questionnaire study. A total of 925 persons were interviewed for 56% coverage in a stratified sampling design. Four species (moose, Canada goose, caribou, lesser snow goose) accounted for about two-thirds of the 1990 bush food harvest of 687 000 kg, the equivalent of 402 g meat or 97 g protein per adult per day. The replacement value of the bush food harvested in the region was about 7.8millionin1990.Includingotherproductsoftheland(fur,fuelwood,berries),thetotalvalueofthetraditionaleconomy,7.8 million in 1990. Including other products of the land (fur, fuelwood, berries), the total value of the traditional economy, 9.4 million for the region or $8400 per household per year, was about one-third as large as the total cash economy. The results show that the traditional economy is a cornerstone of the regional mixed economy, and that such a mixed economy may persist as a culturally and environmentally sustainable base for the region.Key words: Hudson Bay and James Bay Lowland, Canadian subarctic, Cree, sustainable development, subsistence, wildlife, fisheriesDans le but d'aider les Cris Omushkego à planifier une stratégie de développement économique communautaire et régional qui tienne compte de l'économie traditionnelle, on a mis au point des méthodologies appropriées permettant d'enquêter sur l'importance quantitative et sur la valeur économique de la chasse et de la pêche pour la région de Mushkegowuk, dans les basses-terres de la baie d'Hudson et de la baie James. Une étude faite à l'aide d'un sondage a permis d'évaluer le nombre de prises d'animaux par les 6500 autochtones habitant les huit communautés de Moose Factory, Moosonee, New Post, Fort Albany, Kashechewan, Attawapiskat, Peawanuck et Fort Severn. Un total de 925 personnes ont été interviewées formant 56 p. cent d'un plan d'échantillonnage stratifié. Quatre espèces (l'orignal, la bernache du Canada, le caribou et la petite oie blanche) comptaient pour environ les deux tiers des prises provenant de la nature au cours de l'année 90. Le poids de ces prises était de 687 000 kg, soit l'équivalent quotidien de 402 g de viande ou de 97 g de protéine par adulte. La valeur de remplacement de la nourriture tirée de la nature dans la région était d'environ 7,8 millions de dollars en 1990. Si l'on inclut les autres produits de la nature (fourrure, bois de feu, baies), la valeur totale de l'économie traditionnelle - 9,4 millions de dollars pour la région ou 8400 dollars annuels par foyer - équivalait à environ un tiers de l'économie monétaire totale. Les résultats montrent que l'économie traditionnelle est un pilier de l'économie mixte régionale et que cette dernière peut persister en tant qu'assise durable sur le plan culturel et environnemental pour la région.Mots clés: basses-terres de la baie d’Hudson et de la baie James, subarctique canadien, Cris, développement durable, subsistance, faune, pêcherie

    The Persistence of Aboriginal Land Use: Fish and Wildlife Harvest Areas in the Hudson and James Bay Lowland, Ontario

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    The question of the extent and importance of contemporary aboriginal land use in the Canadian North remains controversial, despite more than 20 studies undertaken since the mid-1970s to document Native land claims and to assess impacts of development projects. In planning a community and regional development strategy that takes into account traditional land use and economy, methodologies were developed for a computer-based, integrated land use and wildlife harvest study that could be applied over large geographic areas. Wildlife harvesting areas used in 1990 by the aboriginal people of the Mushkegowuk region, Hudson and James Bay Lowland, were documented by interviewing 925 hunters from eight communities (Moose Factory, Moosonee, New Post, Fort Albany, Kashechewan, Attawapiskat, Peawanuck and Fort Severn). Results show that geographically extensive land use for hunting and fishing persists in the Mushkegowuk region, some 250 000 sq km. However, the activity pattern of Omushkego (West Main) Cree harvesters has changed much over the decades; contemporary harvesting involves numerous short trips of a few days' duration instead of the traditional long trips. Although the First Nations control only 900 sq km (0.36% of the region) as Indian reserve land, they continue to use large parts of their traditional territory.Key words: land use, aboriginal territories, Hudson Bay and James Bay Lowland, Canadian subarctic, Cree, subsistence, wildlife, fisheriesLa question du niveau et de l'importance de l'utilisation actuelle des terres aborigènes dans le Nord canadien demeure controversée, malgré plus de 20 études entreprises depuis le milieu des années 70 afin de documenter les revendications territoriales des autochtones et d'évaluer l'impact des projets de développement. Dans le but de planifier une stratégie de développement communautaire et régional qui tienne compte de l'utilisation des terres et de l'économie traditionnelles, on a mis au point des méthodologies pour une étude intégrée de l'utilisation des terres et prélèvement faunique, en se servant d'ordinateurs, méthodologies qui pourraient être appliquées à de vastes régions géographiques. On a documenté les zones de prélèvement faunique utilisées en 1990 par les peuples autochtones de la région de Mushkegowuk, basse-terre de la baie d'Hudson et de la baie James, en interviewant 925 chasseurs de huit communautés (Moose Factory, Moosonee, New Post, Fort Albany, Kashechewan, Attawapiskat, Peawanuck et Fort Severn). Les résultats montrent qu'une utilisation intensive, du point de vue géographique, pour la chasse et la pêche persiste dans la région de Mushkegowuk, soit quelque 250 000 km². Cependant, le type d'activité de prélèvement des Cree Omushkego (West Main) a beaucoup changé au cours des ans; les prélèvements contemporains sont réalisés lors de nombreuses expéditions de quelques jours seulement, plutôt que lors de longues expéditions traditionnelles. Bien que les Premières Nations ne contrôlent que 900 km² (0,36 p. cent de la région) en tant que terres de réserve indienne, elles continuent d'utiliser une grande superficies du territoire traditionnel.Mots clés: utilisation des terres, territoires autochtones, basse-terre de la baie d’Hudson et de la baie James, subarctique canadien, Cree, subsistance, faune, pêcherie

    Osteopoikilosis: Pain as a Presenting Symptom in Three Family Members

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    Osteopoikilosis is a rare asymptomatic sclerosing bony dysplasia of benign origin. It is usually found incidentally on radiological examinations. Familial occurrence indicates a genetic milieu with autosomal dominant pattern. Here, we present a case report of a young woman suffering from pelvic pain due to osteopoikilosis (OPK). The same disorder was later found in her son and daughter

    Ectopic expression of Thy-1 in the kidneys of transgenic mice induces functional and proliferative abnormalities.

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    Hybrid human--mouse Thy-1.1 genes were injected into pronuclei of Thy-1.2 mice to produce transgenic animals. A hybrid gene composed of the 5' part of the mouse Thy-1.1 gene combined with the 3' human untranslated regions was expressed abnormally in the kidney podocytes, which resulted in severe protein-uria and subsequent death in several founder mice. A hybrid Thy-1 gene composed of the human coding region with the 5' and 3' flanking regions of the mouse gene was expressed abnormally in a different part of the kidney (the tubular epithelia), which resulted in a proliferative kidney disorder. In addition, a neoplasm was found in the brain of one of these mice. These results show that the Thy-1 protein can play an important role in the activation, proliferation, and differentiation of many different cell types

    Prediction of residual stresses in girth welded pipes using an artificial neural network approach

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    Management of operating nuclear power plants greatly relies on structural integrity assessments for safety critical pressure vessels and piping components. In the present work, residual stress profiles of girth welded austenitic stainless steel pipes are characterised using an artificial neural network approach. The network has been trained using residual stress data acquired from experimental measurements found in literature. The neural network predictions are validated using experimental measurements undertaken using neutron diffraction and the contour method. The approach can be used to predict through-wall distribution of residual stresses over a wide range of pipe geometries and welding parameters thereby finding potential applications in structural integrity assessment of austenitic stainless steel girth welds

    Conventional therapies deplete Brain-Infiltrating adaptive immune cells in a Mouse Model of Group 3 Medulloblastoma implicating Myeloid Cells as favorable immunotherapy targets

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    Medulloblastoma is the most common childhood brain cancer. Mainstay treatments of radiation and chemotherapy have not changed in decades and new treatment approaches are crucial for the improvement of clinical outcomes. To date, immunotherapies for medulloblastoma have been unsuccessful, and studies investigating the immune microenvironment of the disease and the impact of current therapies are limited. Preclinical models that recapitulate both the disease and immune environment are essential for understanding immune-tumor interactions and to aid the identification of new and effective immunotherapies. Using an immune-competent mouse model of aggressive Myc-driven medulloblastoma, we characterized the brain immune microenvironment and changes induced in response to craniospinal irradiation, or the medulloblastoma chemotherapies cyclophosphamide or gemcitabine. The role of adaptive immunity in disease progression and treatment response was delineated by comparing survival outcomes in wildtype C57Bl/6J and in mice deficient in Rag1 that lack mature T and B cells. We found medulloblastomas in wildtype and Rag1-deficient mice grew equally fast, and that craniospinal irradiation and chemotherapies extended survival equally in wildtype and Rag1-deficient mice, suggesting that tumor growth and treatment response is independent of T and B cells. Medulloblastomas were myeloid dominant, and in wildtype mice, craniospinal irradiation and cyclophosphamide depleted T and B cells in the brain. Gemcitabine treatment was found to minimally alter the immune populations in the brain, resulting only in a depletion of neutrophils. Intratumorally, we observed an abundance of Iba1+ macrophages, and we show that CD45high cells comprise the majority of immune cells within these medulloblastomas but found that existing markers are insufficient to clearly delineate resident microglia from infiltrating macrophages. Ultimately, brain resident and peripheral macrophages dominate the brain and tumor microenvironment and are not depleted by standard-of-care medulloblastoma therapies. These populations therefore present a favorable target for immunotherapy in combination with front-line treatments
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