31 research outputs found

    Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

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    无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216

    Modelisation bidimensionnelle des phenomenes de transport dans les bassins sedimentaires par la methode des elements finis

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    SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

    Effects of tumor necrosis factor α on leptin-sensitive intestinal vagal mechanoreceptors in the cat

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    International audienceThe involvement of tumour necrosis factor α (TNF-α) in inflammatory bowel disease (IBD) has been established, and anti-TNF-α has been suggested as a therapeutic approach for the treatment of these pathologies. We studied the effects of TNF-α on leptin-sensitive intestinal vagal units to determine whether TNF-α exerts its effects through the intestinal vagal mechanoreceptors and to investigate its interactions with substances regulating food intake. The activity of intestinal vagal mechanoreceptors was recorded via microelectrodes implanted into the nodose ganglion in anesthetized cats. TNF-α (1 μg, i.a.) increased the discharge frequency of leptin-activated units (type 1 units; P < 0.05) and had no effect on the discharge frequency of leptin-inhibited units (type 2 units). When TNF-α was administered 20 min after sulfated cholecystokinin-8 (CCK), its excitatory effects on type 1 units were significantly enhanced (P < 0.0001) and type 2 units were significantly (P < 0.05) activated. Pre-treatment with Il-1ra (250 μg, i.a.) blocked the excitatory effects of TNF-α on type 1 units whereas the excitatory effects of TNF-α administration after CCK treatment on type 2 units were not modified. The activation of leptin-sensitive units by TNF-α may explain, at least in part, the weight loss observed in IBD.L’implication du TNF-α dans les maladies inflammatoires chroniques intestinales (MICI) est bien établie, ainsi l’utilisation d’anti-TNF-α constitue une nouvelle approche thérapeutique. Pour déterminer l’implication des mécanorécepteurs vagaux dans les effets du TNF-α et préciser ses interactions avec des substances modulant la prise alimentaire, nous avons étudié ses effets sur les unités vagales intestinales sensibles à la leptine. L’activité de ces unités est enregistrée, chez le chat anesthesié, dans le ganglion plexiforme. Le TNF-α augmente la fréquence de décharge des unités activées par la leptine (unités « type 1 ») et n’a pas d’effet sur celle des unités inhibées par la leptine (unités « type 2 »). Administré 20 min après CCK, les effets excitateurs du TNF-α sur les unités de type 1 sont potentialisés et les unités de type 2 sont activées. Un prétraitement par l’Il-1ra bloque les effets excitateurs du TNF-α sur les unités de type 1 alors que, pour les unités de type 2, les effets excitateurs du TNF-α en présence de CCK ne sont pas modifiés. Les effets du TNF-α sur les mécanorécepteurs vagaux pourraient expliquer la perte de poids observée dans les MICI

    No effect of comorbidities on the association between social deprivation and geographical access to the reference care center in the management of colon cancer

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    International audienceBACKGOUND:Patients with colon cancer in France exhibit one of the steepest socioeconomic survival gradients in Europe. Among the putative causes for this situation, comorbidities are frequently incriminated but evidence of this is lacking.AIMS:Measure the influence of social deprivation and geographical access to the reference care center for the management of colon cancer, and the putative role of associated comorbidities.MATERIALS AND METHODS:The study population comprised all 1383 resected colon cancer cases diagnosed between 2005 and 2010 in the area covered by the "Calvados Registry of Digestive Tumors". Social environment was assessed by using the European Deprivation Index and travel time to the reference care center and comorbidities by using Charlson's comorbidity index.RESULTS:Our results confirm the existence of socioeconomic or geographical inequalities at each step of colon cancer management, but without any role of associated comorbidities. The effect of deprivation is mainly explained by age at diagnosis, while travel time to the reference care center is an independent predictor of cancer management.CONCLUSION:We found no effect of comorbidities on the association between socioeconomic factors and the management of colon cancer in this French department

    Cost-Effectiveness Analysis of a Mobile Mammography Unit for Breast Cancer Screening to Reduce Geographic and Social Health Inequalities

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    International audienceBACKGROUND:Breast cancer is the leading cancer in terms of incidence and mortality among women in France. Effective organized screening does exist, however, the participation rate is low, and negatively associated with a low socioeconomic status and remoteness.OBJECTIVES:To determine the cost-effectiveness of a mobile mammography (MM) program to increase participation in breast cancer screening and reduce geographic and social inequalities.METHODS:A cost-effectiveness analysis from retrospective data was conducted from the payer perspective, comparing an invitation to a mobile mammography unit (MMU) or to a radiologist's office (MM or RO group) with an invitation to a radiologist's office only (RO group) (n = 37 461). Medical and nonmedical direct costs were estimated. Outcome was screening participation. The mean incremental cost and effect, the incremental cost-effectiveness ratio, and the cost-effectiveness acceptability curve were estimated.RESULTS:The mean incremental cost for invitation to MM or RO was estimated to be €23.21 (95% CI, 22.64-23.78) compared with RO only, and with a point of participation gain of 3.8% (95% CI, 2.8-4.8), resulting in an incremental cost per additional screen of €610.69 (95% CI, 492.11-821.01). The gain of participation was more important in women living in deprived areas and for distances exceeding 15 km from an RO.CONCLUSION:Screening involving a MMU can increase participation in breast cancer screening and reduce geographic and social inequalities while being more cost-effective in remote areas and in deprived areas. Because of the retrospective design, further research is needed to provide more evidence of the effectiveness and cost-effectiveness of using a MMU for organized breast cancer screening and to determine the optimal conditions for implementing it

    Could mobile mammography reduce social and geographic inequalities in breast cancer screening participation?

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    International audienceEvaluation of mobile mammography for reducing social and geographic inequalities in breast cancer screening participation. We examined the responses to first invitations to undergo breast cancer screening from 2003 to 2012 in Orne, a French department. Half of the participants could choose between screening in a radiologist's office or a mobile mammography (MM) unit. We calculated the participation rate and individual participation model according to age group, deprivation quintile and distance. Among participants receiving an MM invitation, the preference was for MM. This was especially the case in the age group >70years and increased with deprivation quintile and remoteness. There were no significant participation trends with regard to deprivation or remoteness. In the general population, the influence of deprivation and remoteness was markedly diminished. After adjustment, MM invitation was associated with a significant increase in individual participation (odds ratio=2.9). MM can target underserved and remote communities, allowing greater participation and decreasing social and geographic inequalities in the general population. Proportionate universalism is an effective principle for public health policy in reducing health inequalities

    Colorectal cancer among farmers in the AGRICAN cohort study

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    OBJECTIVES: Specific farming types and tasks have rarely been studied in relation to colorectal cancer (CRC). We evaluated associations between 5 types of livestock and 13 types of crops in relation to CRC and its subsites within the Agriculture and Cancer (AGRICAN) study. METHODS: AGRICAN cohort includes 181,842 agricultural workers living in 11 French geographical areas. Data on farming types and tasks was collected by self-administered questionnaires. We identified 2 609 CRC, 972 right colon, 689 left colon and 898 rectal incident cancer cases during follow-up from 2005 to 2015. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). RESULTS: Significantly increased CRC risk was observed for farmers producing horses (HR=1.18, 95% CI 1.06-1.31), sunflower (HR=1.23, 95% CI 1.03-1.45) and field vegetables (HR=1.18, 95% CI 1.02-1.36). Positive associations were also observed for pig, poultry and wheat/barley. Some associations were observed only for specific subsites: left colon cancer was associated with fruit growing (HR=1.36, 95% CI 1.09-1.70) and potato (HR=1.28, 95% CI 1.05-1.57). Tasks related to livestock (animal care, insecticide treatment, disinfection of milking equipment and building) or to crop (haymaking, sowing, pesticide treatment, seed treatment, harvesting) were also associated with CRC. Duration and size of farming types/task increased the risk for some of the associations. Analysis stratified by sex suggested an interaction with several farming types/task. CONCLUSIONS: The current study showed original and positive findings for several farming types and tasks and CRC risk, overall and by subsites
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