757 resultados para prerequisite
Resumo:
The competiveness within the global market has forced large manufacturing companies to reorganize their global operations. To act proficiently abroad is therefore no longer a choice but an important prerequisite. In global production networks, there are different plant roles that serve different purposes. One of the important roles within these networks is the core plant role. There are limited amount of the researches done regarding the core plant role. There is also a lack of consistency regarding the definition of the core plant role. It is also evident that there is a knowledge gap regarding the managerial aspects of this plant role both in the academia and in the industry. Managing a core plant requires certain capabilities. It is important to target this knowledge gap since global manufacturing is becoming a common norm for large enterprises and the importance of the core plant role is getting more evident. There is also a lack of understanding towards the challenges that a core plant must deal with both within the organization and globally towards the other plants within the manufacturing network. To address this knowledge gap further, two research questions were created ―What key capabilities are required in order to manage the core plant role?” (RQ1) and ―What are the main challenges in managing the core plant role?” (RQ2). Case study was chosen as the research method for this study since it is the most appropriate method when investigating a phenomenon in its own context. Interviews were the main research technique used to collect data. 18 semi-structured interviews were conducted in eight different cases. A literature review was conducted and was the foundation for the interview guide used in the interviews and for the data analysis. The results show that various capabilities are important for the management of the core plant role. Proximity to R&D and knowledge were the most emphasized factors. For the main challenges in terms of managing a core plant, the communication, cooperation and coordination where the most challenging aspects. Based upon finding, two frameworks have been proposed a concluding generalization and contribution of this research study. The study provides a generalization based upon data that has been collected from companies from different industries. These findings are a contribution towards both the large enterprises operating globally and the academia.
Resumo:
Adeno-associated viral (AAV) vectors are among the most widely used gene transfer systems in basic and pre-clinical research and have been employed in more than 160 clinical trials. AAV vectors are commonly produced in producer cell lines like HEK293 by co-transfection with a so-called vector plasmid and one (in this work) or two so-called helper plasmids. The vector plasmid contains the transgene cassette of interest (TEC) flanked by AAV’s inverted terminal repeats (ITRs) which serve as packaging signals, whereas the helper plasmid provides the required AAV and helper virus functions in trans. A pivotal aspect of AAV vectorology is the manufacturing of AAV vectors free from impurities arising during the production process. These impurities include AAV vector preparations that contain capsids containing prokaryotic sequences, e.g. antibiotic resistance genes originating from the producer plasmids. In the first part of the thesis we aimed at improving the safety of AAV vectors. As we found that encapsidated prokaryotic sequences (using the ampicillin resistance gene as indicator) cannot be re-moved by standard purification methods we investigated whether the producer plasmids could be replaced by Minicircles (MCs). MCs are circular DNA constructs which contain no functional or coding prokaryotic sequences; they only consist of the TEC and a short sequence required for production and purification. MC counterparts of a vector plasmid encoding for enhanced green fluorescent (eGFP) protein and a helper plasmid encoding for AAV serotype 2 (AAV2) and helper Adenovirus (Ad) genes were designed and produced by PlasmidFactory (Bielefeld, Germany). Using all four possible combinations of plasmid and MCs, single-stranded AAV2 vectors (ssAAV) and self-complementary AAV vectors (scAAV) were produced and characterized for vector quantity, quality and functionality. The analyses showed that plasmids can be replaced by MCs without decreasing the efficiency of vector production and vector quality. MC-derived scAAV vector preparations even exceeded plasmid-derived preparations, as they displayed up to 30-fold improved transduction efficiencies. Using MCs as tools, we found that the vector plasmid is the main source of encapsidated prokaryotic sequences. Remarkably, we found that plasmid-derived scAAV vector preparations contained a much higher relative amount of prokaryotic sequences (up to 26.1 %, relative to TEC) compared to ssAAV vector preparations (up to 2.9 %). By replacing both plasmids by MCs the amount of functional prokaryotic sequences could be decreased to below the limit of quantification. Additional analyses for DNA impurities other than prokaryotic sequences showed that scAAV vectors generally contained a higher amount of non-vector DNA (e.g. adenoviral sequences) than ssAAV vectors. For both, ssAAV and scAAV vector preparations, MC-derived vectors tended to contain lower amounts of foreign DNA. None of the vectors tested could be shown to induce immunogenicity. In summary we could demonstrate that the quality of AAV vector preparations could be significantly improved by replacing producer plasmids by MCs. Upon transduction of a target tissue, AAV vector genomes predominantly remain in an episomal state, as duplex DNA circles or concatemers. These episomal forms mediate long-term transgene expression in terminally differentiated cells, but are lost in proliferating cells due to cell division. Therefore, in the second part of the thesis, in cooperation with Claudia Hagedorn and Hans J. Lipps (University Witten/Herdecke) an AAV vector genome was equipped with an autonomous replication element (Scaffold/matrix attachment region (S/MAR)). AAV-S/MAR encoding for eGFP and a blasticidin resistance gene and a control vector with the same TEC but lacking the S/MAR element (AAV-ΔS/MAR) were produced and transduced into highly proliferative HeLa cells. Antibiotic pressure was employed to select for cells stably maintaining the vector genome. AAV-S/MAR transduced cells yielded a higher number of colonies than AAV-ΔS/MAR-transduced cells. Colonies derived from each vector transduction were picked and cultured further. They remained eGFP-positive (up to 70 days, maximum cultivation period) even in the absence of antibiotic selection pressure. Interestingly, the mitotic stability of both AAV-S/MAR and control vector AAV-ΔS/MAR was found to be a result of episomal maintenance of the vector genome. This finding indicates that, under specific conditions such as the mild selection pressure we employed, “common” AAV vectors persist episomally. Thus, the S/MAR element increases the establishment frequency of stable episomes, but is not a prerequisite.
Resumo:
The purpose of this work in progress study was to test the concept of recognising plants using images acquired by image sensors in a controlled noise-free environment. The presence of vegetation on railway trackbeds and embankments presents potential problems. Woody plants (e.g. Scots pine, Norway spruce and birch) often establish themselves on railway trackbeds. This may cause problems because legal herbicides are not effective in controlling them; this is particularly the case for conifers. Thus, if maintenance administrators knew the spatial position of plants along the railway system, it may be feasible to mechanically harvest them. Primary data were collected outdoors comprising around 700 leaves and conifer seedlings from 11 species. These were then photographed in a laboratory environment. In order to classify the species in the acquired image set, a machine learning approach known as Bag-of-Features (BoF) was chosen. Irrespective of the chosen type of feature extraction and classifier, the ability to classify a previously unseen plant correctly was greater than 85%. The maintenance planning of vegetation control could be improved if plants were recognised and localised. It may be feasible to mechanically harvest them (in particular, woody plants). In addition, listed endangered species growing on the trackbeds can be avoided. Both cases are likely to reduce the amount of herbicides, which often is in the interest of public opinion. Bearing in mind that natural objects like plants are often more heterogeneous within their own class rather than outside it, the results do indeed present a stable classification performance, which is a sound prerequisite in order to later take the next step to include a natural background. Where relevant, species can also be listed under the Endangered Species Act.
Resumo:
Shearing is the process where sheet metal is mechanically cut between two tools. Various shearing technologies are commonly used in the sheet metal industry, for example, in cut to length lines, slitting lines, end cropping etc. Shearing has speed and cost advantages over competing cutting methods like laser and plasma cutting, but involves large forces on the equipment and large strains in the sheet material. The constant development of sheet metals toward higher strength and formability leads to increased forces on the shearing equipment and tools. Shearing of new sheet materials imply new suitable shearing parameters. Investigations of the shearing parameters through live tests in the production are expensive and separate experiments are time consuming and requires specialized equipment. Studies involving a large number of parameters and coupled effects are therefore preferably performed by finite element based simulations. Accurate experimental data is still a prerequisite to validate such simulations. There is, however, a shortage of accurate experimental data to validate such simulations. In industrial shearing processes, measured forces are always larger than the actual forces acting on the sheet, due to friction losses. Shearing also generates a force that attempts to separate the two tools with changed shearing conditions through increased clearance between the tools as result. Tool clearance is also the most common shearing parameter to adjust, depending on material grade and sheet thickness, to moderate the required force and to control the final sheared edge geometry. In this work, an experimental procedure that provides a stable tool clearance together with accurate measurements of tool forces and tool displacements, was designed, built and evaluated. Important shearing parameters and demands on the experimental set-up were identified in a sensitivity analysis performed with finite element simulations under the assumption of plane strain. With respect to large tool clearance stability and accurate force measurements, a symmetric experiment with two simultaneous shears and internal balancing of forces attempting to separate the tools was constructed. Steel sheets of different strength levels were sheared using the above mentioned experimental set-up, with various tool clearances, sheet clamping and rake angles. Results showed that tool penetration before fracture decreased with increased material strength. When one side of the sheet was left unclamped and free to move, the required shearing force decreased but instead the force attempting to separate the two tools increased. Further, the maximum shearing force decreased and the rollover increased with increased tool clearance. Digital image correlation was applied to measure strains on the sheet surface. The obtained strain fields, together with a material model, were used to compute the stress state in the sheet. A comparison, up to crack initiation, of these experimental results with corresponding results from finite element simulations in three dimensions and at a plane strain approximation showed that effective strains on the surface are representative also for the bulk material. A simple model was successfully applied to calculate the tool forces in shearing with angled tools from forces measured with parallel tools. These results suggest that, with respect to tool forces, a plane strain approximation is valid also at angled tools, at least for small rake angles. In general terms, this study provide a stable symmetric experimental set-up with internal balancing of lateral forces, for accurate measurements of tool forces, tool displacements, and sheet deformations, to study the effects of important shearing parameters. The results give further insight to the strain and stress conditions at crack initiation during shearing, and can also be used to validate models of the shearing process.
Resumo:
Las teorías administrativas se han basado, casi sin excepción, en los fundamentos y los modelos de la ciencia clásica (particularmente, en los modelos de la física newtoniana). Sin embargo, las organizaciones actualmente se enfrentan a un mundo globalizado, plagado de información (y no necesariamente conocimiento), hiperconectado, dinámico y cargado de incertidumbre, por lo que muchas de las teorías pueden mostrar limitaciones para las organizaciones. Y quizá no por la estructura, la lógica o el alcance de las mismas, sino por la falta de criterios que justifiquen su aplicación. En muchos casos, las organizaciones siguen utilizando la intuición, las suposiciones y las verdades a medias en la toma de decisiones. Este panorama pone de manifiesto dos hechos: de un lado, la necesidad de buscar un método que permita comprender las situaciones de cada organización para apoyar la toma de decisiones. De otro lado, la necesidad de potenciar la intuición con modelos y técnicas no tradicionales (usualmente provenientes o inspiradas por la ingeniería). Este trabajo busca anticipar los pilares de un posible método que permita apoyar la toma de decisiones por medio de la simulación de modelos computacionales, utilizando las posibles interacciones entre: la administración basada en modelos, la ciencia computacional de la organización y la ingeniería emergente.
Resumo:
Como futuros administrados es importante recordar que nuestra función no será únicamente crear una empresa y generar constantemente ingresos. Esto es una de tantas tareas que tiene una persona que se encamina por crear o ser parte de una empresa, sea grande o pequeña siempre existirán variables que con los años se han convertido más y más indispensables en los procesos de este recorrido. El tema principal de nuestro estudio de caso es entender el concepto del endomarketing o como muchos lo conocen marketing interno; en pocas palabras es algo que por años se ha visto su efectividad en la productividad y satisfacción de los empleados. Google es una de las multinacionales más grandes del mundo, que el ultimo reconocimiento fue por parte de uno de los ranking más influyentes “The World’s Billionaries” ocupando como el CEO de la compañía Larry Page el puesto #12 , que por años ha sabido invertir en su recurso más importante que son sus empleados. En una entrevista con la revista Fortune, Larry exclama que “es importante que la empresa sea una familia, que las personas sientan que son parte de la empresa, y que la empresa es como una familia para ellos. Cuando se trata a las personas de esa manera, se obtiene una mejor productividad”. Con este pequeño ejemplo e idea de cómo una de las marcas más influyentes en el mundo ha fortalecido su mejor recurso por años el cual le ha remunerado con el éxito que tiene hoy en día. Entonces es como el mercadeo interno o endomarketing siendo uno de los conceptos tratados en el mercadeo en general hoy en día, logrando meterse como un modelo de negocio en la mayoría de empresas que existen hoy. Este es uno de los motivos que nos motivó para desarrollar este estudio de caso que verán a continuación, el cual se basa en la investigación y análisis de variables que comprenden a la empresa Petrofac, y si bien ha sabido implementar el concepto en sus procesos diarios. El estudio de caso describe como a través de los años ha sabido implementar con éxito la herramienta de evaluación y análisis del mercado interno a los empleados que constituyen hoy en día Petrofac International Limited. Abarcaremos primero con los objetivos del estudio, seguido del inicio y crecimiento de la empresa en los últimos años, en que países tiene presencia y cuáles son sus proyectos más importantes hoy en día. El estudio de caso será implementado por un tipo de investigación descriptiva, que con la recopilación de suficiente información tanto cuantitativa como cualitativa nos ira fortaleciendo la hipótesis principal, usaremos datos estadísticos que serán recopilados de encuestas, entrevistas y focus group. Al final con el análisis y a las conclusiones que lleguemos se busca demostrar el impacto positivo que ha tenido los empleados de diferentes países y de diferentes culturas que poco a poco han influenciado a la empresa para alcanzar el éxito que ha logrado hasta ahora, y de la misma forma como la empresa ha influenciado en cada una de las vidas de estas personas sin importar el lugar en el que estén laborando, siempre la empresa busca que se sientan parte de ella. Como resultados generales, se obtienen argumentos que sustentan que la implementación del mercadeo interno le permite a la empresa generar ventajas competitivas y dinámicas, que son desarrolladas internamente para un futuro reflejarlas ante los clientes externos. El estudio permitió concluir que el mercadeo interno debe ser una estrategia de comunicación dentro de una empresa convirtiéndose de primera necesidad para la compañía, pues los beneficios que genera son cada vez más necesarios para cada área que abarca el negocio.
Resumo:
The tribe Longidorini within the subfamily Longidorinae (Longidorus spp. and Paralongidorus spp.) and the subfamily Xiphineminae (Xiphinema spp.) are two large nematode groups with about 260 and 230 known species, respectively. They are globally two important groups of ectoparasitic nematodes considered to be major pests because of their activity as vectors of important plant nepovirus, with some species included in the list of quarantine pathogenic organisms in many European countries. Knowledge of the biodiversity and occurrence of this nematode group is a prerequisite for the establishment of sound management strategies and control measures. According to data collected from the databases (such as EPPO, FSTA, and Web of Science) and published in specialised literature, a total of 15 Longidorus, 1 Paralongidorus and 40 Xiphinema species have been recorded as present in Portugal. However, the taxonomic status of some species is controversial, and thus needs to be clarified. A comprehensive review for unravelling the biodiversity and occurrence of nematode species of the genus Longidorus, Paralongidorus and Xiphinema in Portugal is herein provided. This review includes an updated checklist of species with information on the localities, host plants and geographical distribution. Additionally, maps on the species distributions of Longidorinae and Xiphineminae nematodes present in Continental Portugal and the Portuguese Macaronesian islands are provided, as well as unpublished data on authors and comments on the current taxonomic status. Finally, new insights and directions for future research on Longidoridae in Portugal are presented.