The journeys and the "rewriting" in Vertigo by W. G. Sebald

W.G. Sebald (1944–2001) is considered one of the important authors in German literature after World War II and also is a writer with a special influence in contemporary world literature. Sebald’s first prose work, Vertigo (Schwindel. Gefühle), carries in embryonic form all the motifs that can be encountered in the Sebaldian corpus, specifically the motif of travel, in close connection with the theme of memory. Based on the intertextuality approach, the article aims to interpret the relationship between different kinds of texts on the plot of many vertiginous journeys through space, time, and point out the borders between history and representation, text/image and reality, life, and writing. In doing this research, the author uses the qualitative method with a descriptive approach to disclose the discursive strategies of a superposition of text types in a highly complex narrative. The article has analyzed the plot’s structure of four parts and the overlapping text layers in the novel and found that Vertigo is written in travel style. The story is like a pilgrimage; however, the narrator is not a tourist, but like a “flâneur” on drift journeys (according to Guy Debord’s dérive theory). And Sebald, in a way, always tended to portray scenes haunted by grief and loss. The physical spaces in Sebald’s work are always inlaid with historical, cultural, metaphysical, and psychological sediments, making it not simply a place to visit. The Sebald-flâneur’s journey often deliberately drifts to the periphery, wandering in the edge, they are a traveller who does not intend to relax, whose movement is drawn from emotions arising from the outside landscape. Moreover, from the result of analysing Sebald’s narrative techniques, the author has demonstrated that Vertigo is also a hypertext, that every symbol in a text is also a collection of networks of links to innumerable other texts. It is a labyrinth expressing the concept of the “rewriting” of existing texts. Sebald seems to want to create a feeling of “schwindel” (vertigo) to encourage a viewing, which reads as if it were against the tyranny of a mono-discourse. The novel becomes a space for experiments to break down genre boundaries. The work is a warning for the “reading” since fiction could be nonfiction and vice versa. Therefore, this novel can be read as a collection of short stories with the idea: the “writing” merely “rewriting” over existing texts

Role of Leukocyte-specific protein 1 in acute lung inflammation

Leukocyte-specific protein 1 (LSP1), an F-actin binding protein, is involved in neutrophil recruitment into peritoneum. Because mechanisms of excessive migration of activated neutrophils into inflamed lungs, credited with tissue damage, are not fully understood, we explored the hitherto unknown expression and role of LSP1 in neutrophil migration in a mouse model of acute lung inflammation. We induced acute lung inflammation through intranasal E. coli lipopolysacharide (LPS) (80μg) in wild-type 129/SvJ (WT) and LSP1 deficient (LSP1-/-) mice. WT (n=10) and LSP1-/- (n=11) mice showed significant neutrophilia and more neutrophils in bronchoalveolar lavage (BAL) at 9 hour post-LPS challenge compared to respective saline-treated controls (WT=7; LSP1-/-=10). LPS treatment induced more BAL neutrophils (P<0.001), myeloperoxidase concentrations and Gr-1+ neutrophils in lung tissues in WT mice compared to LSP1-/- mice. Lung myeloperoxidase and Gr-1+ (P<0.05) were higher in LPS-treated WT compared to the LSP1-/- mice. Lung tissue and BAL fluid KC, MCP-1, MIP-1α and MIP-1β concentration and vascular permeability were not different between LPS-treated WT and LSP1-/- mice but TNF-α concentration was higher in LPS-treated WT mice. Hematoxylin and eosin staining showed more septal congestion in LPS-treated WT mice compared to LSP1-/- mice. LSP1 expression was increased in lungs from LPS-treated mice compared to saline control. The autopsied lungs from septic humans, compared to their respective controls, showed increased expression of LSP1. These data show that LSP1 expression is modulated in acute lung inflammation and that LSP1 deficiency reduces neutrophil migration into acute lung inflammation

ROLE OF RGDSK HELICAL ROSETTE NANOTUBES (RGDSK-HRNs) IN INTESTINAL MUCOSAL IMMUNE RESPONSE TO E. COLI INFECTION

Integrin αvβ3 is a transmembrane receptor recognizing arginine-glycine-aspartic acid (RGD) tripeptide. However, the expression and functions of integrin αvβ3 in intestinal epithelium in diarrhea, particularly due to E. coli infection, have been poorly understood. Therefore, we performed a series of experiments to fill the gap information. We found that integrin αvβ3 is localized on the plasma membrane, the cytoplasm, and the nucleus of IPEC1 cells. The expression of integrin αvβ3 on IPEC1 decreased at 15 minutes but returned to normal after 90 minutes of infection with E. coli F4 (P<0.05). The light, fluorescent and electron microscopy, western blots, and 96-well plate binding assays showed the presence of integrin αvβ3-like protein domain in E. coli F4. The data from binding assays on 96-well plates also suggests that E. coli F4 may have an RGD-like sequence binding to host integrin αvβ3. Immunohistochemistry showed normal porcine jejuna strongly expressed integrin αvβ3 in the nucleus and the apical surface of epithelia as well as crypts. Integrin αvβ3 expression was decreased in the epithelium but increased in the vascular endothelium of the jejunum infected with E. coli or E. coli associated with Salmonella (P<0.05). Immunogold electron microscope confirmed the presence of integrin αvβ3 in the porcine jejunal epithelium and E. coli. Flow cytometry showed that RGDSK-HRNs did not significantly increase dead IPEC1. RGDSK-HRNs improved IPEC1 cell survival upon E. coli infection compared with E. coli infection alone group (P<0.05). Western blot showed that in E. coli infection, RGDSK-HRNs-FITC significantly decreased the level of p-p53 compared with monoclonal anti-integrin αvβ3 antibody treatment, and the level of p-p38MAPK compared with RGDSK-FITC group (P<0.05). The data from ex vivo villus adhesion assays showed that RGDSK-HRNs-FITC significantly reduced the number of E. coli adhering to villi for up to 12 hours compared with the E. coli-only challenged group (P<0.05). Both RGDSK-FITC peptide and monoclonal anti-integrin αvβ3 antibody were effective in inhibiting the E. coli binding to villi for up to 24 hours compared with the E. coli-only challenged group (P<0.05). Consistently, in the in vivo porcine gut loop model, RGDSK-HRNs-FITC significantly decreased the number of E. coli binding to villi compared with E. coli treatment group (P<0.05). RGDSK-HRNs-FITC did not significantly decrease the number of E. coli colonies in the supernatant. In conclusion, our study highlighted that integrin αvβ3 was involved in E. coli colonization in the porcine intestine. Also, the novel RGDSK-HRNs-FITC could inhibit the attachment of E. coli to the epithelium, suggesting a potential intervention in combination with anti-microbial and other treatments for E. coli infection in the future

Meta-heuristic Solution Methods for Rich Vehicle Routing Problems

Le problème de tournées de véhicules (VRP), introduit par Dantzig and Ramser en 1959, est devenu l'un des problèmes les plus étudiés en recherche opérationnelle, et ce, en raison de son intérêt méthodologique et de ses retombées pratiques dans de nombreux domaines tels que le transport, la logistique, les télécommunications et la production. L'objectif général du VRP est d'optimiser l'utilisation des ressources de transport afin de répondre aux besoins des clients tout en respectant les contraintes découlant des exigences du contexte d’application. Les applications réelles du VRP doivent tenir compte d’une grande variété de contraintes et plus ces contraintes sont nombreuse, plus le problème est difficile à résoudre. Les VRPs qui tiennent compte de l’ensemble de ces contraintes rencontrées en pratique et qui se rapprochent des applications réelles forment la classe des problèmes ‘riches’ de tournées de véhicules. Résoudre ces problèmes de manière efficiente pose des défis considérables pour la communauté de chercheurs qui se penchent sur les VRPs. Cette thèse, composée de deux parties, explore certaines extensions du VRP vers ces problèmes. La première partie de cette thèse porte sur le VRP périodique avec des contraintes de fenêtres de temps (PVRPTW). Celui-ci est une extension du VRP classique avec fenêtres de temps (VRPTW) puisqu’il considère un horizon de planification de plusieurs jours pendant lesquels les clients n'ont généralement pas besoin d’être desservi à tous les jours, mais plutôt peuvent être visités selon un certain nombre de combinaisons possibles de jours de livraison. Cette généralisation étend l'éventail d'applications de ce problème à diverses activités de distributions commerciales, telle la collecte des déchets, le balayage des rues, la distribution de produits alimentaires, la livraison du courrier, etc. La principale contribution scientifique de la première partie de cette thèse est le développement d'une méta-heuristique hybride dans la quelle un ensemble de procédures de recherche locales et de méta-heuristiques basées sur les principes de voisinages coopèrent avec un algorithme génétique afin d’améliorer la qualité des solutions et de promouvoir la diversité de la population. Les résultats obtenus montrent que la méthode proposée est très performante et donne de nouvelles meilleures solutions pour certains grands exemplaires du problème. La deuxième partie de cette étude a pour but de présenter, modéliser et résoudre deux problèmes riches de tournées de véhicules, qui sont des extensions du VRPTW en ce sens qu'ils incluent des demandes dépendantes du temps de ramassage et de livraison avec des restrictions au niveau de la synchronization temporelle. Ces problèmes sont connus respectivement sous le nom de Time-dependent Multi-zone Multi-Trip Vehicle Routing Problem with Time Windows (TMZT-VRPTW) et de Multi-zone Mult-Trip Pickup and Delivery Problem with Time Windows and Synchronization (MZT-PDTWS). Ces deux problèmes proviennent de la planification des opérations de systèmes logistiques urbains à deux niveaux. La difficulté de ces problèmes réside dans la manipulation de deux ensembles entrelacés de décisions: la composante des tournées de véhicules qui vise à déterminer les séquences de clients visités par chaque véhicule, et la composante de planification qui vise à faciliter l'arrivée des véhicules selon des restrictions au niveau de la synchronisation temporelle. Auparavant, ces questions ont été abordées séparément. La combinaison de ces types de décisions dans une seule formulation mathématique et dans une même méthode de résolution devrait donc donner de meilleurs résultats que de considérer ces décisions séparément. Dans cette étude, nous proposons des solutions heuristiques qui tiennent compte de ces deux types de décisions simultanément, et ce, d'une manière complète et efficace. Les résultats de tests expérimentaux confirment la performance de la méthode proposée lorsqu’on la compare aux autres méthodes présentées dans la littérature. En effet, la méthode développée propose des solutions nécessitant moins de véhicules et engendrant de moindres frais de déplacement pour effectuer efficacement la même quantité de travail. Dans le contexte des systèmes logistiques urbains, nos résultats impliquent une réduction de la présence de véhicules dans les rues de la ville et, par conséquent, de leur impact négatif sur la congestion et sur l’environnement.For more than half of century, since the paper of Dantzig and Ramser (1959) was introduced, the Vehicle Routing Problem (VRP) has been one of the most extensively studied problems in operations research due to its methodological interest and practical relevance in many fields such as transportation, logistics, telecommunications, and production. The general goal of the VRP is to optimize the use of transportation resources to service customers with respect to side-constraints deriving from real-world applications. The practical applications of the VRP may have a variety of constraints, and obviously, the larger the set of constraints that need to be considered, i.e., corresponding to `richer' VRPs, the more difficult the task of problem solving. The needs to study closer representations of actual applications and methodologies producing high-quality solutions quickly to larger-sized application problems have increased steadily, providing significant challenges for the VRP research community. This dissertation explores these extensional issues of the VRP. The first part of the dissertation addresses the Periodic Vehicle Routing Problem with Time Windows (PVRPTW) which generalizes the classical Vehicle Routing Problem with Time Windows (VRPTW) by extending the planning horizon to several days where customers generally do not require delivery on every day, but rather according to one of a limited number of possible combinations of visit days. This generalization extends the scope of applications to many commercial distribution activities such as waste collection, street sweeping, grocery distribution, mail delivery, etc. The major contribution of this part is the development of a population-based hybrid meta-heuristic in which a set of local search procedures and neighborhood-based meta-heuristics cooperate with the genetic algorithm population evolution mechanism to enhance the solution quality as well as to promote diversity of the genetic algorithm population. The results show that the proposed methodology is highly competitive, providing new best solutions in some large instances. The second part of the dissertation aims to present, model and solve two rich vehicle routing problems which further extend the VRPTW with time-dependent demands of pickup and delivery, and hard time synchronization restrictions. They are called Time-dependent Multi-zone Multi-Trip Vehicle Routing Problem with Time Windows (TMZT-VRPTW), and Multi-zone Mult-Trip Pickup and Delivery Problem with Time Windows and Synchronization (MZT-PDTWS), respectively. These two problems originate from planning the operations of two-tiered City Logistics systems. The difficulty of these problems lies in handling two intertwined sets of decisions: the routing component which aims to determine the sequences of customers visited by each vehicle, and the scheduling component which consists in planning arrivals of vehicles at facilities within hard time synchronization restrictions. Previously, these issues have been addressed separately. Combining these decisions into one formulation and solution method should yield better results. In this dissertation we propose meta-heuristics that address the two decisions simultaneously, in a comprehensive and efficient way. Experiments confirm the good performance of the proposed methodology compared to the literature, providing system managers with solution requiring less vehicles and travel costs to perform efficiently the same amount of work. In the context of City Logistics systems, our results indicate a reduction in the presence of vehicles on the streets of the city and, thus, in their negative impact on congestion and environment

Experiencing nature-based tourism through the human senses : a phenomenological approach

Nature-based tourism has become one of the fastest growing sectors within the tourism industry, due to an increased demand for better recreation and relaxation means in nature at the turn of the 21st century. While nature-based tourism has received much of academic and general attention, the same cannot be said about the influence of the human senses on nature-based tourism experience. In fact, it was only until very recently that the academic community started paying attention to the importance of the senses and attempted to discover a more holistic way to approach the sensescape. The purpose of this master’s thesis is to discover the influence of the senses on nature-based tourism experience. Given that the study in question is phenomenological, a qualitative approach was adopted to best understand the research subject. A number of semi-structured interviews were conducted to gain an insight of how each individual perceive the influences that the senses have on their overall experience in nature. The results showed that while the senses have actual influences on one’s experience in nature, not all the senses have such impact equally. Sight appeared to be the dominant sense, followed by hearing, with the remaining senses being secondary in importance. Furthermore, the interview sessions also revealed an appreciation for nature and nature-based tourism, which is a common sentiment among the participants. Further research should pay attention to the interactions between the senses, as well as the utilization of experiential point during the experience design phase

Red-emitting Ba2Si5N8Eu2+ conversion phosphor: A new selection for enhancing the optical performance of the in-cup packaging MCW-LEDs

In this research, the influence of the red-emitting Ba2Si5N8Eu2+ convention phosphor on the optical performance of the 7,000K and 7,700K in-cup packaging multi-chip white LEDs (MCW-LEDs) is investigated. The effect of the red-emitting Ba2Si5N8Eu2+ convention phosphor is demonstrated based on Mie Theory by Mat Lab and Light Tools software. The research results indicated that the optical performance of MCW-LEDs was crucially affected by the red-emitting Ba2Si5N8Eu2+ phosphor's concentration. This paper provides an essential recommendation for selecting and developing the phosphor materials for MW-LEDs manufacturing.Web of Science51art. no. 148615

Impact of maintenance on replacement investment under technological improvement

International audienceAn unexplored important area in the equipment investment problem under technological improvement is the impact of maintenance policy. In fact, maintenance not only helps to maximize the profitability of the asset, but also prolong its economic life while waiting the apparition of better technology in the near future. Therefore, we propose a model that allows us to consider how replacement investment in a new or improved asset will be influenced by maintenance. The investment decisions are based on information about the profitability of the current asset and the technological environment. For the maintenance process, we also consider the dependency of its cost and efficiency on the deterioration state of asset that is represented by a profit parameter. We use a non-stationary Markov decision process to solve for the optimal investment/maintenance policy and illustrate the potential benefits of integrating maintenance policies in the investment strategy through different numerical analysis

Optimal Maintenance and Replacement Decisions under Technological Change

International audienceThe requirement of equipment improvement in order to satisfy the safety and reliability of system motivates the development of technology. The presence or expectation of technologically better equipment will influence managerial decisions on whether to invest in the maintenance of current equipment, invest in replacement with an equivalent model, replacement with a higher technology model currently available on the market, or wait for a potentially even better technology to appear in the near future. Hence, the consideration of technological change is a very important aspect for maintenance and replacement decisions. This paper aims to define a model that allows us to gain insight into how maintenance/replacement policies will be influenced by the expectation of future technology. We then use stochastic dynamic programming (i.e., Markov decision process) to solve for the optimal maintenance and replacement policy of the equipment as a function of performance and cost. Finally, we illustrate the problem through several numerical example

System-level prognostics based on inoperability input-output model

International audienceNowadays, the modern industry is increasingly demanding the availability and reliability of production systems as well as the reduction of maintenance costs. The techniques to achieving these goals are recognized and discussed under the term of Prognostics and Health Management (PHM). However, the prognostics is often approached from a component point of view. The system-level prognostics (SLP), taking into account interdependencies and multi-interactions between system components, is still an underexplored area. Inspired from the inoperability input-output model (IIM), a new approach for SLP is proposed in this paper. The inoperability corresponds to the component’s degradation, i.e. the reduction of its performance in comparison to an ideal reference state. The interactions between component degradation and the effect of the environment are included when estimating the inoperability of components and also when predicting the system remaining useful life (SRUL). This approach can be applied to complex systems involving multi-heterogeneous components with a reasonable computational effort. Thus, it allows overcoming the lack of scope and scalability of the traditional approaches used in PHM. An illustrative example is presented and discussed in the paper to highlight the performance of the proposed approach