880 resultados para Multi-agent system


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Multi-phase postmortem CT angiography (MPMCTA) is recognized as a valuable tool to explore the vascular system, with higher sensitivity than conventional autopsy. However, a limitation is the impossibility to diagnose pulmonary embolism (PE) due to post-mortem blood clots situated in pulmonary arteries. The purpose of this study was to explore an eventual possibility to distinguish between real PE and artefacts mimicking PE. Our study included 416 medico-legal cases. All of them underwent MPMCTA, conventional autopsy and histological examination. We selected cases presenting arterial luminal filling defects in the pulmonary arteries. Their radiological interpretation was confronted to the one of autopsy and histological examination. We also investigated an eventual correlation between artefacts in pulmonary arteries and those in other parts of the vascular system. In 123 cases, filling defects of pulmonary arteries were described during MPMCTA. In 57 cases, this was interpreted as artefact and in 4 cases as suspected PE. In 62 cases only a differential diagnosis was made. Autopsy and histology could clearly identify the artefacts as such. Only one case of real PE was radiologically misinterpreted as artefact. In 6 of the 62 cases with no interpretation a PE was diagnosed. In 3 out of 4 suspected cases, PE was confirmed. We found out that filling defects in pulmonary arteries are nearly always associated to other vascular artefacts. Therefore, we suggest following some rules for radiological interpretation in order to allow a reliable diagnosis of pulmonary embolism after MPMCTA.

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OBJECTIVE: The objective of our study was to establish optimal perfusion conditions for high-resolution postmortem angiography that would permit dynamic visualization of the arterial and venous systems. MATERIALS AND METHODS: Cadavers of two dogs and one cat were perfused with diesel oil through a peristaltic pump. The lipophilic contrast agent Lipiodol Ultra Fluide was then injected, and angiography was performed. The efficiency of perfusion was evaluated in the chick chorioallantoic membrane. RESULTS: Vessels could be seen up to the level of the smaller supplying and draining vessels. Hence, both the arterial and the venous sides of the vascular system could be distinguished. The chorioallantoic membrane assay revealed that diesel oil enters microvessels up to 50 microm in diameter and that it does not penetrate the capillary network. CONCLUSION: After establishing a postmortem circulation by diesel oil perfusion, angiography can be performed by injection of Lipiodol Ultra Fluide. The resolution of the images obtained up to 3 days after death is comparable to that achieved in clinical angiography.

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This document presents the results of a state-of-practice survey of transportation agencies that are installing intelligent transportation sensors (ITS) and other devices along with their environmental sensing stations (ESS) also referred to as roadway weather information system (RWIS) assets.

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This paper presents a customizable system used to develop a collaborative multi-user problem solving game. It addresses the increasing demand for appealing informal learning experiences in museum-like settings. The system facilitates remote collaboration by allowing groups of learners tocommunicate through a videoconferencing system and by allowing them to simultaneously interact through a shared multi-touch interactive surface. A user study with 20 user groups indicates that the game facilitates collaboration between local and remote groups of learners. The videoconference and multitouch surface acted as communication channels, attracted students’ interest, facilitated engagement, and promoted inter- and intra-group collaboration—favoring intra-group collaboration. Our findings suggest that augmentingvideoconferencing systems with a shared multitouch space offers newpossibilities and scenarios for remote collaborative environments and collaborative learning.

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Statistical properties of binary complex networks are well understood and recently many attempts have been made to extend this knowledge to weighted ones. There are, however, subtle yet important considerations to be made regarding the nature of the weights used in this generalization. Weights can be either continuous or discrete magnitudes, and in the latter case, they can additionally have undistinguishable or distinguishable nature. This fact has not been addressed in the literature insofar and has deep implications on the network statistics. In this work we face this problem introducing multiedge networks as graphs where multiple (distinguishable) connections between nodes are considered. We develop a statistical mechanics framework where it is possible to get information about the most relevant observables given a large spectrum of linear and nonlinear constraints including those depending both on the number of multiedges per link and their binary projection. The latter case is particularly interesting as we show that binary projections can be understood from multiedge processes. The implications of these results are important as many real-agent-based problems mapped onto graphs require this treatment for a proper characterization of their collective behavior.

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The goal of this work was to move structural health monitoring (SHM) one step closer to being ready for mainstream use by the Iowa Department of Transportation (DOT) Office of Bridges and Structures. To meet this goal, the objective of this project was to implement a pilot multi-sensor continuous monitoring system on the Iowa Falls Arch Bridge such that autonomous data analysis, storage, and retrieval can be demonstrated. The challenge with this work was to develop the open channels for communication, coordination, and cooperation of various Iowa DOT offices that could make use of the data. In a way, the end product was to be something akin to a control system that would allow for real-time evaluation of the operational condition of a monitored bridge. Development and finalization of general hardware and software components for a bridge SHM system were investigated and completed. This development and finalization was framed around the demonstration installation on the Iowa Falls Arch Bridge. The hardware system focused on using off-the-shelf sensors that could be read in either “fast” or “slow” modes depending on the desired monitoring metric. As hoped, the installed system operated with very few problems. In terms of communications—in part due to the anticipated installation on the I-74 bridge over the Mississippi River—a hardline digital subscriber line (DSL) internet connection and grid power were used. During operation, this system would transmit data to a central server location where the data would be processed and then archived for future retrieval and use. The pilot monitoring system was developed for general performance evaluation purposes (construction, structural, environmental, etc.) such that it could be easily adapted to the Iowa DOT’s bridges and other monitoring needs. The system was developed allowing easy access to near real-time data in a format usable to Iowa DOT engineers.

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This report proposes, that for certain types of highway construction projects undertaken by the Iowa Department of Transportation, a scheduling technique commonly referred to as linear scheduling may be more effective than the Critical Path Method scheduling technique that is currently being used. The types of projects that appear to be good candidates for the technique are those projects that have a strong linear orientation. Like a bar chart, this technique shows when an activity is scheduled to occur and like a CPM schedule it shows the sequence in which activities are expected to occur. During the 1992 construction season, the authors worked with an inlay project on Interstate 29 to demonstrate the linear scheduling technique to the Construction Office. The as-planned schedule was developed from the CPM schedule that the contractor had developed for the project. Therefore, this schedule represents what a linear representation of a CPM schedule would look like, and not necessarily what a true linear schedule would look like if it had been the only scheduling technique applied to the project. There is a need to expand the current repertoire of scheduling techniques to address those projects for which the bar chart and CPM may not be appropriate either because of the lack of control information or due to overly complex process for the actual project characteristics. The scheduling approaches used today on transportation projects have many shortcomings for properly modeling the real world constraints and conditions which are encountered. Linear project's predilection for activities with variable production rates, a concept very difficult to handle with the CPM, is easily handled and visualized with the linear technique. It is recommended that work proceed with the refinement of the method of linear scheduling described above and the development of a microcomputer based system for use by the Iowa Department of Transportation and contractors for its implementation. The system will be designed to provide the information needed to adjust schedules in a rational understandable method for monitoring progress on the projects and alerting Iowa Department of Transportation personnel when the contractor is deviating from the plan.

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The genus Silene, studied by Darwin, Mendel and other early scientists, is re-emerging as a system for studying interrelated questions in ecology, evolution and developmental biology. These questions include sex chromosome evolution, epigenetic control of sex expression, genomic conflict and speciation. Its well-studied interactions with the pathogen Microbotryum has made Silene a model for the evolution and dynamics of disease in natural systems, and its interactions with herbivores have increased our understanding of multi-trophic ecological processes and the evolution of invasiveness. Molecular tools are now providing new approaches to many of these classical yet unresolved problems, and new progress is being made through combining phylogenetic, genomic and molecular evolutionary studies with ecological and phenotypic data.

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BACKGROUND: An ADME (absorption, distribution, metabolism and excretion)-pharmacogenetics association study may identify functional variants relevant to the pharmacokinetics of lopinavir co-formulated with ritonavir (LPV/r), a first-line anti-HIV agent. METHODS: An extensive search of literature and web resources helped select ADME genes and single nucleotide polymorphisms (SNPs, functional and HapMap tagging SNPs) with a proven or potentially relevant role in LPV/r pharmacokinetics. The study followed a two-stage design. Stage 1 (discovery) considered a Caucasian population (n=638) receiving LPV/r, where we selected 117 individuals with low LPV clearance (cases) and 90 individuals with high clearance (controls). Genotyping was performed by a 1536-SNP customized GoldenGate Illumina BeadArray. Stage 2 (confirmation) represented a replication study of candidate SNPs from the stage 1 in 148 individuals receiving LPV/r. The analysis led to formal population pharmacokinetic-pharmacogenetic modeling of demographic, environmental and candidate SNP effects. RESULTS: One thousand three hundred and eighty SNPs were successfully genotyped. Nine SNPs prioritized by the stage 1 analysis were brought to replication. Stage 2 confirmed the contribution of two functional SNPs in SLCO1B1, one functional SNP in ABCC2 and a tag SNP of the CYP3A locus in addition to body weight effect and ritonavir coadministration. According to the population pharmacokinetic-pharmacogenetic model, genetic variants explained 5% of LPV variability. Individuals homozygous rs11045819 (SLCO1B1*4) had a clearance of 12.6 l/h, compared with 5.4 l/h in the reference group, and 3.9 l/h in individuals with two or more variant alleles of rs4149056 (SLCO1B1*5), rs717620 (ABCC2) or rs6945984 (CYP3A). A subanalysis confirmed that although a significant part of the variance in LPV clearance was attributed to fluctuation in ritonavir levels, genetic variants had an additional effect on LPV clearance. CONCLUSION: The two-stage strategy successfully identified genetic variants affecting LPV/r pharmacokinetics. Such a general approach of ADME pharmacogenetics should be generalized to other drugs.

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This paper analyzes the asymptotic performance of maximum likelihood (ML) channel estimation algorithms in wideband code division multiple access (WCDMA) scenarios. We concentrate on systems with periodic spreading sequences (period larger than or equal to the symbol span) where the transmitted signal contains a code division multiplexed pilot for channel estimation purposes. First, the asymptotic covariances of the training-only, semi-blind conditional maximum likelihood (CML) and semi-blind Gaussian maximum likelihood (GML) channelestimators are derived. Then, these formulas are further simplified assuming randomized spreading and training sequences under the approximation of high spreading factors and high number of codes. The results provide a useful tool to describe the performance of the channel estimators as a function of basicsystem parameters such as number of codes, spreading factors, or traffic to training power ratio.

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Diplomityö muodostuu kahdesta kokonaisuudesta. Työn teoriaosa kertoo mitä ympäristöjohtaminen on, millaisia ovat multi-site -organisaatio ja multi-site -johtamisjärjestelmä sekä mitä vaatimuksia nämä asettavat yritykselle. Työssä esitetään malli, jota käyttämällä kansainvälisten johtamisjärjestelmästandardien mukaan rakennetut laatu-, ympäristö-, terveys- ja turvallisuusjärjestelmät voidaan yhdistää yhdeksi kokonaisuudeksi, multi-site - johtamisjärjestelmäksi. Malli rakentuu kolmesta tasosta, joita ovat paikallinen, maakohtainen ja konsernitaso. Esimerkkien avulla kerrotaan miteneri lähtökohdista voidaan näiden tasojen kautta edetä kohti yhtä johtamiskokonaisuutta. Esille tuodaan myös multi-site -johtamisjärjestelmän käyttöönottoa puoltavat ja vastustavat näkökohdat. Työn konkreettinen osa on johtamisjärjestelmämallin paikallisen tason toteuttaminen. Ympäristöjohtamisjärjestelmän rakentaminen standardin EN ISO 14001:2004 vaatimusten mukaiseksi Kvaerner Power Oy:n Suomen toimipaikoille sekä tämän järjestelmän yhdistäminen sertifioituun EN ISO 9001 -standardin mukaiseen laatujärjestelmään. Työssä kerrotaan miten ympäristöjohtamisjärjestelmä on rakennettu ja miten laatu- ja ympäristöjärjestelmät on liitetty yhdeksi kokonaisuudeksi. Työn tuloksena syntyi malli johtamisjärjestelmien yhdistämisestä sekä sertifioitu ympäristöjohtamisjärjestelmä, jonka yhdistäminen laatujärjestelmään toteutettiin tavoitteiden mukaisesti.

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We studied 5,449 cases of cleft lip (CL) with or without cleft palate (CL/P) identified between 1980 and 2000 from the EUROCAT network of 23 registers (nearly 6 million births) in 14 European countries. We investigated specific types of defects associated with clefts. Among CL/P cases (prevalence = 9.1 per 10,000), 1,996 (36.6%) affected only the lip (CL) and 3,453 (63.4%) involved CL and palate (CLP). A total of 3,860 CL/P cases (70.8%) occurred as isolated anomalies and 1,589 (29.2%) were associated with other defects such as multiple congenital anomalies of unknown origin (970), chromosomal (455) and recognized syndromes (164). Associated malformations were more frequent in infants who had CLP (34.0%) than in infants with CL only (20.8%). Among multi-malformed infants, 2 unrelated anomalies were found in 351 cases, 3 in 242 cases, and 4 or more in 377 cases. Among 5,449 CL/P cases, 4,719 were live births (LB) (86.6%), 203 stillbirths (SB) (3.7%), while 508 (9.3%) were terminations of pregnancy (ToP). CL/P occurred significantly more frequently in males (M/F = 1.70), especially among total isolated cases (M/F = 1.87) and CLP isolated cases (M/F = 1.92). The study confirmed that musculoskeletal, cardiovascular, and central nervous system defects are frequently associated with CL/P. An association with reduction anomalies of the brain was found. This association suggests that clinicians should seek to identify structural brain anomalies in these patients with CL/P as the potential functional consequences may be important for rehabilitation and clinical management.

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Résumé destiné à un large public Le système immunitaire associé aux muqueuses gastro-intestinales doit être capable de protéger notre organisme contre l'invasion de pathogènes. Parallèlement, il doit identifier en Cant que tels, des composés inoffensifs comme la nourriture ou les milliards de bactéries qui résident dans notre intestin. Le travail présenté ici aborde ces deux aspects essentiels au bon fonctionnement de notre muqueuse intestinale. Dans une première partie, la protéine nommée pièce sécrétoire a été étudiée pour ses propriétés protectrices contre le pathogène viral rotavirus. Le rôle de la pièce sécrétoire est de transporter les anticorps que nous produisons vers la surface des muqueuses. En dehors de cette fonction bien connue, il se peut que cette protéine soit également capable de protéger notre organisme contre certains virus. L'hypothèse de travail était donc que la pièce sécrétoire se lie directement au virus, l'empêchant ainsi d'infecter des cellules épithéliales de l'intestin. En utilisant différentes techniques biochimiques, cette hypothèse s'est révélée fausse car aucune interaction entre la pièce sécrétoire et le virus n'a pu être observée, et logiquement, aucune protection n'a pu prendre place. En revanche, la pièce sécrétoire se lie à d'autres structures pathogéniques et permet ainsi de neutraliser leurs effets néfastes. La pièce sécrétoire participe donc activement à la protection de nos muqueuses, en plus de son rôle de transporteur. La deuxième partie de ce travail avait pour sujet les réactions inappropriées que le système immunitaire induit parfois contre un aliment, ou, autrement dit, les allergies alimentaires. Un modèle d'allergie alimentaire à donc été développé chez la souris et a permis de mesurer plusieurs symptômes et facteurs liés à l'allergie. Puis, ce modèle a été utilisé afin de tester les effets bénéfiques d'une bactérie lactique, dite probiotique, sur le développement de l'allergie. Il a été observé que, sous certaines circonstances, l'administration de la bactérie lactique protégeait entièrement les souris contre les réactions allergiques. L'effet bénéfique dépend donc du probiotique mais également d'autres facteurs encore inconnus â ce jour. Cette étude ouvre la voie sur la compréhension des mécanismes liés aux allergies alimentaires et sur l'impact que peuvent avoir les bactéries probiotiques sur cette maladie. Résumé Le système immunitaire associé aux muqueuses intestinales doit être capable de différencier les antigènes inoffensifs tels que 1a nourriture ou les bactéries commensales des microorganismes potentiellement dangereux. Cet aspect est essentiel pour le maintien de l'homéostase intestinale et fait l'objet du travail présenté ici. Dans un premier projet, les propriétés protectrices de la protéine appelée pièce sécrétoire (SC) ont été étudiées. SC est une protéine connue pour le transport des immunoglobulines à la surface des muqueuses. Cette protéine est fortement glycosylée paz des sucres complexes, ce qui nous a mené à postuler que SC puisse interagir avec le pathogène rotavirus. Cette hypothèse était soutenue par le fait que ce virus adhère aux cellules épithéliales par des résidus glycosylés. Des analyses biochimiques et biologiques ont démontré qu'aucune interaction entre SC et le virus ne prenait place, et que par conséquent SC n'offrait aucune protection contre ce pathogène. En revanche, SC interagit avec d'autres structures pathogéniques, comme la toxine A de Clostridium difficile, et la molécule d'adhésion intimine de la bactérie entéropathogène Escherichia coli. La liaison se fait par l'intermédiaire des sucres et confère ainsi une protection contre ces pathogènes. Ainsi, SC a été identifié comme agent neutralisant au niveau de l'intestin. La deuxième partie de ce travail abordait le sujet des allergies alimentaires, et avait pour but de tester les effets bénéfiques potentiels d'une bactérie probiotique, Lactobacillus paracasei NCC2461, contre les réactions allergiques. Un modèle marin d'allergie alimentaire a été mis au point, permettant de mesurer des immunoglobulines E, des symptômes allergiques, et la dégranulation de mastocytes. Lorsque le probiotique a été administré aux souris, celles-ci ont été complètement protégées des réactions allergiques dans une première expérience. Cependant, cette protection n'a pas été reproduite et suggère que des facteurs environnementaux encore inconnus sont critiques pour que le probiotique agisse positivement. Ce travail a permis de mettre en évidence la complexité de l'approche des traitements liés aux probiotiques et ouvre la voie sur la compréhension des mécanismes liés à l'allergie. Abstract The mucosal immune system associated to the gastrointestinal mucosa must efficiently distinguish between innocuous antigens, such as food proteins and commensal bacteria and potentially infectious agents. The work presented here deals with these two essential aspects guaranteeing intestinal homeostasis. In the first part of this work, the protective properties of secretory component (SC) toward the pathogen rotavirus were investigated. SC, which allows the transport of polymeric immunoglobulins (Ig) to mucosal surfaces, is highly glycosylated with complex glycan structures. The abundance and the nature of these carbohydrates led us to speculate that SC might interact with rotavirus, which is known to bind target cells with glycan receptors. Using various biological and biochemical techniques, we demonstrated that SC did not interact with rotaviruses, nor protected epithelial cells from infection. However, SC was shown to bind to Clostridium difficile toxin A and to the enteropathogenic Echerischia coli adhesion molecule intimin in a glycan-dependent fashion. These interactions allow in vitro protection of epithelial cells using physiological concentrations of SC. These data identify SC as a microbial scavenger at mucosal surfaces, and in the context of secretory IgA, further enhance the neutralising properties of the complex. The second project was inscribed in the domain of food allergy and aimed to test the modulatory functions of a probiotic strain of Lactobacillus paracasei toward allergic reactions. A model of food-mediated allergy was developed in the mouse using mucosal sensitisation. Several parameters associated to allergy were quantified after allergen challenge, and included allergen-specific IgE, allergic signs like diarrhea and temperature drop, and degranulation of mast cells. Administration of the probiotic strain was shown to completely protect mice from allergic reactions. However, these data were not reproduced, suggesting that unknown environmental factors are required so that protection mediated by the probiotic strain occurs. This study paves the way to the understanding of the mechanisms associated to allergy, and highlights the tremendous complexity that probiotic treatments will have to face.

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The purpose of this dissertation is to increase the understanding and knowledge of field sales management control systems (i.e. sales managers monitoring, directing, evaluating and rewarding activities) and their potential consequences on salespeople. This topic is important because research conducted in the past has indicated that the choice of control system type can on the other hand have desirable consequences, such as high levels of motivation and performance, and on the other hand leadto harmful unintended consequences, such as opportunistic or unethical behaviors. Despite the fact that marketing and sales management control systems have been under rigorous research for over two decades, it still is at a very early stage of development, and several inconsistencies can be found in the research results. This dissertation argues that these inconsistencies are mainly derived from misspecification of the level of analysis in the past research. These different levels of analysis (i.e. strategic, tactical, and operational levels) involve very different decision-making situations regarding the control and motivation of sales force, which should be taken into consideration when conceptualizing the control. Moreover, the study of salesperson consequences of a field sales management control system is actually a cross-level phenomenon, which means that at least two levels of analysis are simultaneously involved. The results of this dissertation confirm the need to re-conceptualize the field sales management control system concept. It provides empirical evidence for the assertion that control should be conceptualized with more details atthe tactical/operational level of analysis than at the strategic levelof analysis. Moreover, the results show that some controls are more efficiently communicated to field salespeople than others. It is proposed that this difference is due to different purposes of control; some controls aredesigned for influencing salespersons' behavior (aim at motivating) whereas some controls are designed to aid decision-making (aim at providing information). According to the empirical results of this dissertation, the both types of controls have an impact to the sales force, but this impactis not as strong as expected. The results obtained in this dissertation shed some light to the nature of field sales management control systems, and their consequences on salespeopl

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The increasing prevalence of chronic diseases and multi-morbidity represents challenges for health systems worldwide. In that perspective, the current organization of healthcare delivery, fragmentation of care, limited use of evidence-based guidelines and patients'insufficient empowerment are some reasons explaining the current limited effectiveness of the management of chronically ill patients. Based on theoretical models such as the Chronic Care Model (CCM), initiatives targeting improvements in the care of patients with chronic diseases have been implemented worldwide since more than a decade. Their development in Switzerland, a health system where more than half of practices are still single handed [6], is only recent and infrequent. Structured programs for patients with chronic diseases or multimorbidity usually propose patient-centered interventions and consider an integrative multidisciplinary approach. Currently, little is known on the existence of such programs and on the role of family physicians (FPs)within these programs, in Switzerland. The objective of this study was to identify and describe current structured programs targeting chronic diseases or multi-morbidity in Switzerland. This may help in examining innovative approaches that are only developed locally but would deserve wider interest for further implementation. We conducted a telephone-based survey between June and November 2013 and contacted systematically key institutions, informants and stakeholders nationwide and in the 26 cantons...