991 resultados para Traffic Engineering


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This thesis researches automatic traffic sign inventory and condition analysis using machine vision and pattern recognition methods. Automatic traffic sign inventory and condition analysis can be used to more efficient road maintenance, improving the maintenance processes, and to enable intelligent driving systems. Automatic traffic sign detection and classification has been researched before from the viewpoint of self-driving vehicles, driver assistance systems, and the use of signs in mapping services. Machine vision based inventory of traffic signs consists of detection, classification, localization, and condition analysis of traffic signs. The produced machine vision system performance is estimated with three datasets, from which two of have been been collected for this thesis. Based on the experiments almost all traffic signs can be detected, classified, and located and their condition analysed. In future, the inventory system performance has to be verified in challenging conditions and the system has to be pilot tested.

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Yeast multi-copy vectors carrying the formaldehyde-resistance marker gene SFA have proved to be a valuable tool for research on industrially used strains of Saccharomyces cerevisiae. The genetics of these strains is often poorly understood, and for various reasons it is not possible to simply subject these strains to protocols of genetic engineering that have been established for laboratory strains of S. cerevisiae. We tested our vectors and protocols using 10 randomly picked baker's and wine yeasts all of which could be transformed by a simple protocol with vectors conferring hyperresistance to formaldehyde. The application of formaldehyde as a selecting agent also offers the advantage of its biodegradation to CO2 during fermentation, i.e., the selecting agent will be consumed and therefore its removal during down-stream processing is not necessary. Thus, this vector provides an expression system which is simple to apply and inexpensive to use

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Optical tracers in conjunction with fluorescence microscopy have become widely used to follow the movement of synaptic vesicles in nerve terminals. The present review discusses the use of these optical methods to understand the regulation of exocytosis and endocytosis of synaptic vesicles. The maintenance of neurotransmission depends on the constant recycling of synaptic vesicles and important insights have been gained by visualization of vesicles with the vital dye FM1-43. A number of questions related to the control of recycling of synaptic vesicles by prolonged stimulation and the role of calcium to control membrane internalization are now being addressed. It is expected that optical monitoring of presynaptic activity coupled to appropriate genetic models will contribute to the understanding of membrane traffic in synaptic terminals.

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This thesis focuses on the development of sustainable industrial architectures for bioenergy based on the metaphors of industrial symbiosis and industrial ecosystems, which imply exchange of material and energy side-flows of various industries in order to improve sustainability of those industries on a system level. The studies on industrial symbiosis have been criticised for staying at the level of incremental changes by striving for cycling waste and by-flows of the industries ‘as is’ and leaving the underlying industry structures intact. Moreover, there has been articulated the need for interdisciplinary research on industrial ecosystems as well as the need to extend the management and business perspectives on industrial ecology. This thesis addresses this call by applying a business ecosystem and business model perspective on industrial symbiosis in order to produce knowledge on how industrial ecosystems can be developed that are sustainable environmentally and economically. A case of biogas business is explored and described in four research papers and an extended summary that form this thesis. Since the aim of the research was to produce a normative model for developing sustainable industrial ecosystems, the methodology applied in this research can be characterised as constructive and collaborative. A constructive research mode was required in order to expand the historical knowledge on industrial symbiosis development and business ecosystem development into the knowledge of what should be done, which is crucial for sustainability and the social change it requires. A collaborative research mode was employed through participating in a series of projects devoted to the development of a biogas-for-traffic industrial ecosystem. The results of the study showed that the development of material flow interconnections within industrial symbiosis is inseparable from larger business ecosystem restructuring. This included a shift in the logic of the biogas and traffic fuel industry and a subsequent development of a business ecosystem that would entail the principles of industrial symbiosis and localised energy production and consumption. Since a company perspective has been taken in this thesis, the role of an ecosystem integrator appeared as a crucial means to achieve the required industry restructuring. This, in turn, required the development of a modular and boundary-spanning business model that had a strong focus on establishing collaboration among ecosystem stakeholders and development of multiple local industrial ecosystems as part of business growth. As a result, the designed business model of the ecosystem integrator acquired the necessary flexibility in order to adjust to local conditions, which is crucial for establishing industrial symbiosis. This thesis presents a normative model for the development of a business model required for creating sustainable industrial ecosystems, which contributes to approaches at the policy-makers’ level, proposed earlier. Therefore, this study addresses the call for more research on the business level of industrial ecosystem formation and the implications for the business models of the involved actors. Moreover, the thesis increases the understanding of system innovation and innovation in business ecosystems by explicating how business model innovation can be the trigger for achieving more sustainable industry structures, such as those relying on industrial symbiosis.

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In the 70's, pancreatic islet transplantation arose as an attractive alternative to restore normoglycemia; however, the scarcity of donors and difficulties with allotransplants, even under immunosuppressive treatment, greatly hampered the use of this alternative. Several materials and devices have been developed to circumvent the problem of islet rejection by the recipient, but, so far, none has proved to be totally effective. A major barrier to transpose is the highly organized islet architecture and its physical and chemical setting in the pancreatic parenchyma. In order to tackle this problem, we assembled a multidisciplinary team that has been working towards setting up the Human Pancreatic Islets Unit at the Chemistry Institute of the University of São Paulo, to collect and process pancreas from human donors, upon consent, in order to produce purified, viable and functional islets to be used in transplants. Collaboration with the private enterprise has allowed access to the latest developed biomaterials for islet encapsulation and immunoisolation. Reasoning that the natural islet microenvironment should be mimicked for optimum viability and function, we set out to isolate extracellular matrix components from human pancreas, not only for analytical purposes, but also to be used as supplementary components of encapsulating materials. A protocol was designed to routinely culture different pancreatic tissues (islets, parenchyma and ducts) in the presence of several pancreatic extracellular matrix components and peptide growth factors to enrich the beta cell population in vitro before transplantation into patients. In addition to representing a therapeutic promise, this initiative is an example of productive partnership between the medical and scientific sectors of the university and private enterprises.

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Greenhouse gases emitted from energy production and transportation are dramatically changing the climate of Planet Earth. As a consequence, global warming is affecting the living conditions of numerous plant and animal species, including ours. Thus the development of sustainable and renewable liquid fuels is an essential global challenge in order to combat the climate change. In the past decades many technologies have been developed as alternatives to currently used petroleum fuels, such as bioethanol and biodiesel. However, even with gradually increasing production, the market penetration of these first generation biofuels is still relatively small compared to fossil fuels. Researchers have long ago realized that there is a need for advanced biofuels with improved physical and chemical properties compared to bioethanol and with biomass raw materials not competing with food production. Several target molecules have been identified as potential fuel candidates, such as alkanes, fatty acids, long carbon‐chain alcohols and isoprenoids. The current study focuses on the biosynthesis of butanol and propane as possible biofuels. The scope of this research was to investigate novel heterologous metabolic pathways and to identify bottlenecks for alcohol and alkane generation using Escherichia coli as a model host microorganism. The first theme of the work studied the pathways generating butyraldehyde, the common denominator for butanol and propane biosynthesis. Two ways of generating butyraldehyde were described, one via the bacterial fatty acid elongation machinery and the other via partial overexpression of the acetone‐butanol‐ethanol fermentation pathway found in Clostridium acetobutylicum. The second theme of the experimental work studied the reduction of butyraldehyde to butanol catalysed by various bacterial aldehyde‐reductase enzymes, whereas the final part of the work investigated the in vivo kinetics of the cyanobacterial aldehyde deformylating oxygenase (ADO) for the generation of hydrocarbons. The results showed that the novel butanol pathway, based on fatty acid biosynthesis consisting of an acyl‐ACP thioesterase and a carboxylic acid reductase, is tolerant to oxygen, thus being an efficient alternative to the previous Clostridial pathways. It was also shown that butanol can be produced from acetyl‐CoA using acetoacetyl CoA synthase (NphT7) or acetyl‐CoA acetyltransferase (AtoB) enzymes. The study also demonstrated, for the first time, that bacterial biosynthesis of propane is possible. The efficiency of the system is clearly limited by the poor kinetic properties of the ADO enzyme, and for proper function in vivo, the catalytic machinery requires a coupled electron relay system.

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Sleep disorders are not uncommon and have been widely reported throughout the world. They have a profound impact on industrialized 24-h societies. Consequences of these problems include impaired social and recreational activities, increased human errors, loss of productivity, and elevated risk of accidents. Conditions such as acute and chronic insomnia, sleep loss, excessive sleepiness, shift-work, jet lag, narcolepsy, and sleep apnea warrant public health attention, since residual sleepiness during the day may affect performance of daily activities such as driving a car. Benzodiazepine hypnotics and zopiclone promote sleep, both having residual effects the following day including sleepiness and reduced alertness. In contrast, the non-benzodiazepine hypnotics zolpidem and zaleplon have no significant next-day residual effects when taken as recommended. Research on the effects of wakefulness-promoting drugs on driving ability is limited. Countermeasures for excessive daytime sleepiness have a limited effect. There is a need for a social awareness program to educate the public about the potential consequences of various sleep disorders such as narcolepsy, sleep apnea, shift-work-related sleep loss, and excessive daytime sleepiness in order to reduce the number of sleep-related traffic accidents.

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This paper describes the development situation of biofuel in China and the research progress and application in transportation and aviation area, including several key technologies of biofuel production: biofuel pretreatment and handling. This paper is aiming to find the best storing, transmitting, feeding and pretreating methods of various materials, as well as a comparison among the advantages and disadvantages of different pretreatment methods, which is expected to reduce cost in production process and reach the maximized benefits. Meanwhile, a case study of one biomass fuel production factory in China is presented with evaluation and analysis on their technology application.

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This study discusses the significance of having service as a business logic, and more specifically, how value co-creation can be seen as an enhancing phenomenon to business-to-business relationships in traditional business sector. The purpose of this study is to investigate how value cocreation can enhance a business-to-business relationship in the heating, ventilation and airconditioning (HVAC) industry of building services engineering, through three sub-objectives: to identify what is value in the industry, how value is co-created in the industry, and what is value in a business-to-business relationship in the industry. The theoretical part this study consists of academic knowledge and literature related to the concepts of value, value co-creation and business-to-business relationships. In order to research value co-creation and business-to-business relationships in HVAC industry of building services engineering both, metaphorical and conceptual thinking of service dominant (S-D) logic and more managerial approach of service logic (SL), contributed to the theoretical part of the study. The empirical research conducted for this study is based on seven semi-structured interviews, which constituted the holistic, qualitative single case study method chosen for the research. The data was collected in September 2014 from CEOs, managers and owners representing six building services engineering firms. The interviews were analysed with the help of transcriptions, role-ordered matrices and thematic networks. The findings of this study indicate that value in HVAC industry consists of client expertise and supplier expertise. The result of applying client expertise and supplier expertise to the business-to- business relationship is characterized as value-in-reputation, when continuity, interaction, learning and rapport of the business relationship are ensured. As a result, value co-creation in the industry consists of mutual and separate elements, which the client and the supplier apply in the process, in addition to proactive interaction. The findings of this study, together with the final framework, enhance the understanding of the connection existing between value co-creation and business-to-business relationship. The findings suggest that value in the HVAC industry is characterized by both value-in-use and value-inreputation. Value-in-reputation enhances the formation of value-in-use, and consequently, value cocreation enhances the business-to-business relationship. This study thus contributes to the existing knowledge on the concepts of value and value co-creation in business-to-business relationships.

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Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.

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Utvecklingen av flercelliga organismer är en mångfacetterad process som kräver kommunikation celler emellan. Under utvecklingen av en organism måste cellerna göra vissa val, vilket bestämmer riktningen för deras fortsatta utveckling. Utgående från dessa val erhåller cellerna egenskaper som är karaktäristiska för olika celltyper. Notch-signalräckan är en viktig reglerare av valet mellan olika cellöden. Notch-signalräckan aktiveras när Notch-receptorer som uttrycks på ytan av en cell binder till Notch-ligander som uttrycks på ytan av en annan närliggande cell. Denna avhandling belyser mekanismerna som reglerar omsättningen av såväl Notch-receptorer som -ligander till och från cellmembranen, samt ökar förståelsen för hur dessa mekanismer påverkar Notch-medierade cellöden i stamceller. Internalisering av Notch receptorer anses nödvändigt för fullständig aktivering av Notch-signalvägen. De bakomliggande molekylära mekanismerna är dock fortfarande oklara. Vi har upptäckt att atypiskt protein kinas Cζ (aPKCζ) reglerar internaliseringen av Notch-receptorer. aPKCζ fosforylerar Notch, vilket leder till receptorns internalisering, men effekten är beroende av receptorns signaleringsstatus. Vi visar att aPKCζ reglerar Notch-signaleringen och styr både neuroners och muskelcellers differentiering. Ytterligare har vi analyserat samspelet mellan cellskelettet och Notch-signalvägen. Våra resultat visar att intermediärfilamenten, en del av cellskelettet, är viktiga reglerare av Notch-signaleringen både under neuronal och vaskulär utveckling. Intermediärfilamenten vimentin och GFAP reglerar uttrycket av Notch-ligander vid cellmembranen i hjärnans stödceller, astrocyterna, och påverkar därmed neuronala stamcellers cellödesbeslut. Vimentin är även viktigt reglerare av Notch-signalräckan vid angiogenesen. Celler som saknar vimentin uppvisar avvikande Notch-signalering emedan möss som saknar vimentin påvisar en fördröjd utveckling av vaskulaturen under embryonalstadiet. ------------------------------------------------- Monisoluisten organismien kehittyminen on monimutkainen prosessi, joka vaatii viestintää solujen välillä. Kehittymisen aikana solut joutuvat tiettyjen valintojen eteen, mitkä tulevat määrittämään niiden erilaistumisen suunnan. Solut omaksuvat solutyypille ominaisia ominaisuuksia näihin valintoihin perustuen Notch-signalointireitti säätelee solujen erilaistumista eri suuntiin. Notch-signalointireitti aktivoituu, kun Notch-reseptori yhden solun pinnalla sitoo Notch-ligandin toisen, viereisen solun solukalvolla. Tutkimukseni lisää tuntemusta Notch-reseptoreiden ja ligandien solun sisäisestä liikennöinnistä ja sitä säätelevistä mekanismeista, sekä tämän säätelyn vaikutuksista kantasulojen erilaistumiseen. Notch-signalointireitin aktivoituminen vaatii reseptoreiden ja ligandien sisäistämisen solukalvolta, mutta taustalla olevat ja sisäistymistä säätelevät mekanismit ovat vielä epäselviä. Tutkimukseni osoittaa, että atyyppinen proteiinikinaasi Cζ (aPKCζ) säätelee Notch-reseptoreiden endosytoosia. Endosytoosin lopputulos riippuu siitä onko reseptori aktivoitunut ligandin välityksellä vai ei. Tuloksemme osoittavat aPKCζ säätelevän Notch-signalointia ja kontrolloivan sekä hermosolujen, että lihassolujen erilaistumista. Analysoimme myös Notch-signaloinnin ja solun tukirangan vuorovaikutuksia. Välikokoiset filamentit, jotka ovat osa tukirankaa, säätelevät Notch-signalointia neuronaalisen erilaistumisen sekä verisuonten uudismuodostumisen aikana. Vimentiini ja GFAP ovat välikokoisia säikeitä, jotka säätelevät Notch-ligandien ekspressiota astrosyyttien, eli aivojen hermotukisolujen solukalvolla. Vimentiini säätelee myös Notch-signalointireittiä angiogeneesin aikana. Vimentiiniä vailla olevilla soluilla ilmenee heikentynyttä Notch-signalointia, joka voidaan liittää hiirillä ilmenevään vimenttiinin puutteesta johtuvaan viivästyneeseen verisuonien kehitykseen.