25 research outputs found
Reactor-based Neutrino Oscillation Experiments
The status of neutrino oscillation searches employing nuclear reactors as
sources is reviewed. This technique, a direct continuation of the experiments
that proved the existence of neutrinos, is today an essential tool in
investigating the indications of oscillations found in studying neutrinos
produced in the sun and in the earth's atmosphere. The low-energy of the
reactor \nuebar makes them an ideal tool to explore oscillations with small
mass differences and relatively large mixing angles.
In the last several years the determination of the reactor anti-neutrino flux
and spectrum has reached a high degree of accuracy. Hence measurements of these
quantities at a given distance L can be readily compared with the expectation
at L = 0, thus testing \nuebar disappearance.
While two experiments, Chooz and Palo Verde, with baselines of about 1 km and
thus sensitive to the neutrino mass differences associated with the atmospheric
neutrino anomaly, have collected data and published results recently, an
ambitious project with a baseline of more than 100 km, Kamland, is preparing to
take data. This ultimate reactor experiment will have a sensitivity sufficient
to explore part of the oscillation phase space relevant to solar neutrino
scenarios. It is the only envisioned experiment with a terrestrial source of
neutrinos capable of addressing the solar neutrino puzzle.Comment: Submitted to Reviews of Modern Physics 34 pages, 39 figure
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Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks
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
Distributed data mining systems: techniques, approaches and algorithms
Nowadays, we are living in the midst of a data explosion and seeing a massive growth in databases so with the wide availability of huge amounts of data; necessarily we are become in need for turning this data into useful information and knowledge, where Data mining uncovers interesting patterns and relationships hidden in a large volume of raw data and big data is a new term used to identify the datasets that are of large size and have grater complexity. The knowledge gained from data can be used for applications such as market analysis, customer retention and production control. Data mining is a massive computing task that deals with huge amount of stored data in a centralized or distributed system to extract useful information or knowledge. In this paper, we will discuss Distributed Data Mining systems, approaches, Techniques and algorithms to deal with distributed data to discover knowledge from distributed data in an effective and efficient way
Modeling of distributed file System in big data storage by event- B
Nowadays, a wide set of systems and application, especially in high performance computing, depends on distributed environments to process and analyses huge amounts of data. As we know, the amount of data increases enormously, and the goal to provide and develop efficient, scalable and reliable storage solutions has become one of the major issue for scientific computing. The storage solution used by big data systems is Distributed File Systems (DFSs), where DFS is used to build a hierarchical and unified view of multiple file servers and shares on the network. In this paper we will offer Hadoop Distributed File System (HDFS) as DFS in big data systems and we will present an Event-B as formal method that can be used in modeling, where Event-B is a mature formal method which has been widely used in a number of industry projects in a number of domains, such as automotive, transportation, space, business information, medical device and so on, And will propose using the Rodin as modeling tool for Event-B, which integrates modeling and proving as well as the Rodin platform is open source, so it supports a large number of plug-in tools
Aortic valve repair in patients with aortic regurgitation: Experience with the first 100 cases
AbstractIntroductionThe aim of this study was to analyze short- and mid-term results of aortic valve repair.Material and methodsOne hundred consecutive patients (24 females; mean age 50.3 years, range 23–77 years) with aortic regurgitation underwent aortic valve repair between November 2007 and October 2012. Sixty patients had bicuspid aortic valve, and 82 patients demonstrated aortic regurgitation greater than mild (> grade 2). The ascending aorta/aortic root was replaced in 67 patients. Aortic cusp repair was necessary in 74 patients and additional aortic annulus stabilization was required in 48 cases. Follow-up ranged from 1 to 59 months (cumulative of 220 patient-years, median 25 months) and was complete in 100%.ResultsThere was no 30-day mortality and two patients died in the follow-up. The overall 4-year survival was 98% and freedom from cardiac death was 99% at 4 years. During the follow-up eight patients underwent aortic valve-related reoperation due to progression of aortic regurgitation and another six patients showed aortic regurgitation more than mild (> grade 2). In both aspects there was no statistically significant difference between patients without and with aortic root replacement (p=0.402 and p=0.650). There were no significant bleeding or thromboembolic events during the follow-up.ConclusionsShort- and mid-term data analysis revealed an excellent survival and acceptable results of aortic repair, comparable with other larger published studies. We think, therefore, aortic valve repair should be a part of contemporary cardio-surgical armamentarium, especially in younger patients with an appropriate indication
Variation in mouse chemical signals is genetically controlled and environmentally modulated
Abstract In most mammals and particularly in mice, chemical communication relies on the detection of ethologically relevant fitness-related cues from other individuals. In mice, urine is the primary source of these signals, so we employed proteomics and metabolomics to identify key components of chemical signalling. We show that there is a correspondence between urinary volatiles and proteins in the representation of genetic background, sex and environment in two house mouse subspecies Mus musculus musculus and M. m. domesticus. We found that environment has a strong influence upon proteomic and metabolomic variation and that volatile mixtures better represent males while females have surprisingly more sex-biased proteins. Using machine learning and combined-omics techniques, we identified mixtures of metabolites and proteins that are associated with biological features
Chemical communication in termites: syn-4,6-Dimethylundecan-1-ol as 3 trail-following pheromone, syn-4,6-dimethylundecanal and 4 (5E)-2,6,10-trimethylundeca-5,9-dienal as the respective male and female sex 5 pheromones in Hodotermopsis sjoestedti (Isoptera, Archotermopsidae)
The trail-following pheromone and sex pheromones were investigated in the Indomalayan termite Hodotermopsis sjoestedti belonging to the new family Archotermopsidae. Gas chromatography coupled to mass spectrometry (GC-MS) after solid phase microextraction (SPME) of the sternal gland secretion of pseudergates and trail-following bioassays demonstrated that the trailfollowing pheromone of H. sjoestedti was syn-4,6-dimethylundecan-1-ol, a new chemical structure for termite pheromones. GC-MS after SPME of the sternal gland secretion of alates also allowed the identification of sex-specific compounds. In female alates, the major sex-specific compound was identified as (5E)-2,6,10-trimethylundeca-5,9-dienal, a compound previously identified as the female sex pheromone of the termite Zootermopsis nevadensis. In male alates, the major sex-specific compound was identified as syn-4,6-dimethylundecanal, a homolog of syn-4,6-dimethyldodecanal, which has previously been confirmed as the male sex pheromone of Z. nevadensis. The presence of sex-specific compounds in alates of H. sjoestedti strongly suggests for this termite the presence of sex-specific pairing pheromones which were only known until now in Z. nevadensis. Our results showed therefore a close chemical relationship between the pheromones of the taxa Hodotermopsis and Zootermopsis and, in contrast, a clear difference with the taxa Stolotermes and Porotermes, which is in total agreement with the recent creation of the families Archotermopsidae and Stolotermitidae as a substitute for the former family Termopsidae
Video_1_Renal cell carcinoma with intracardiac tumor thrombus extension: Radical surgery yields 2 years of postoperative survival in a single-center study over a period of 30 years.wmv
BackgroundRenal cell carcinoma (RCC) with tumor thrombus extension into the right atrium (level IV) is a rare life-threatening clinical condition that can only be managed by means of a combined urological and cardiac surgical approach. The early and late outcomes of this radical treatment were analyzed in a large single-institution series over a period of 30 years.MethodsIn 37 patients with RCC and intracardiac tumor thrombus extension, nephrectomy was performed followed by the extraction of the intracaval and intracardiac tumor thrombus under direct visual control during deep hypothermic circulatory arrest (DHCA). Recently, in 13 patients, selective aortic arch perfusion (SAAP) was instituted during DHCA.ResultsIn all patients, precise removal of the tumor thrombus was accomplished in a bloodless field. The mean duration of isolated DHCA was 15 ± 6 min, and 31.5 ± 10.2 min in the case of DHCA + SAAP, at a mean hypothermia of 22.7 ± 4°C. In-hospital mortality was 7.9% (3 patients). In Kaplan–Meier analysis, the estimated median survival was 26.4 months whereas the 5-year cancer-related survival rate was 51%.ConclusionsDespite its complexity, this extensive procedure can be performed safely with a generally uneventful postoperative course. The use of cardiopulmonary bypass with DHCA, with the advantage of SAAP, allows for a safe, precise, and complete extirpation of intracaval and intracardiac tumor mass. Late outcomes after radical surgical treatment in patients with RCC and tumor thrombus reaching up in the right atrium in our series justify this extensive procedure.</p