Дисертації з теми "Transport and forwarding activity"
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Ткачук, Марія Анатоліївна. "Управління транспортно-експедиторською діяльністю підприємства ( на прикладі ТОВ «Сандора»)". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/24987.
Повний текст джерелаАнотація:
Магістерська дисертація на тему: «Управління транспортно-експедиторською діяльністю підприємства (на прикладі ТОВ «Сандора»)» містить 119 сторінок, 17 таблиць, 13 рисунків, 2 додатка. Перелік посилань нараховує 35 найменування.
Актуальність теми обумовлена постійним розвитком логістичних процесів та можливістю підвищення конкурентних позицій підприємства за рахунок вдосконалення транспортно-експедиторської діяльності.
Магістерська дисертація на здобуття ступеня магістра виконувалась в Національному технічному університеті України «Київський політехнічний інститут імені Ігоря Сікорського» відповідно до планів наукових досліджень кафедри менеджменту за темою «Удосконалення процесів управління логістичними системами українських підприємств в умовах інтеграції у світову економіку» (№ ДР 0117U005641).
Метою роботи є: розширення та поглиблення теоретичних положень про управління транспортно-експедиторською діяльністю, а також розкриття методів оцінки ефективності цієї діяльності на промисловому підприємстві.
Поставлена мета дослідження обумовлена вирішенням таких завдань:
– розглянути сутність та основні теоретичні засади щодо управління транспортно-експедиторською діяльністю;
– здійснити діагностику стану функціонування підприємства сокової промисловості;
– обґрунтувати сутність логістичного підходу в управлінні транспортно-експедиторської діяльності та визначити основні методи оцінювання ефективності управління транспортно-експедиторською діяльністю;
– провести аналіз та здійснити характеристику галузі транспортно-експедиторської діяльності;
– здійснити діагностування діяльності обраного підприємства в сфері надання транспортно-експедиторських послуг;
– оцінити ефективність управління транспортно-експедиторської діяльності на ТОВ «Сандора» та запропонувати шляхи удосконалення;
– обґрунтувати доцільність напрямів вдосконалення системи управління транспортно-логістичної діяльності на ТОВ «Сандора».
Об’єктом дослідження є процес управління транспортно-експедиторською діяльністю підприємства.
Предметом дослідження виступають теоретично-методологічні аспекти та практичний інструментарій управління транспортно-експедиторською діяльністю підприємства.
В магістерській роботі застосовувалася сукупність загальних та специфічних наукових методів, таких як системний підхід, методи економічного та статистичного аналізу, групування, графічного моделювання організаційних структур, експертної оцінки. Для отримання аналітичної інформації були використані дані статистичної звітності, внутрішньої, зокрема, бухгалтерської звітності підприємств та а матеріали практикуючих фахівців в галузі менеджменту та логістики, розміщені в підручниках та електронних джерелах.
Наукова новизна дослідження полягає у:
– поглибленню та уточненню існуючих теоретичних засад з питання управління транспортно-експедиторською діяльністю підприємства;
– систематизація оцінки ефективності методів управління транспортно-експедиторської діяльності;
– запропоновано нові рішення щодо організації роботи транспортно-експедиторської діяльності;
– виявлено та узагальнено проблеми управління транспортними витратами;
– запропоноване рішення щодо оптимізації транспортних витрат та скорочення часу поставок транспортно-логістичного відділу підприємства.
Практичне значення полягає у розробці методів оптимізації логістичних витрат на оплату праці, а саме доплати за понаднормовому роботу водіїв та експедиторів, а також та зменшення постійних витрат оплату за найманий транспорт за рахунок створення свого автопарку легкових машин. Розроблена програма по удосконаленню роботи транспортно-експедиторської діяльності допоможе підвисити якість наданих послуг та посилити конкурентні позиції на ринку.
Розроблені в магістерській дисертації на здобуття ступеня магістра рекомендації та пропозиції щодо вдосконалення механізму роботи транспортно-експедиторської діяльності були представлені на розгляд ради директорів ТОВ «Сандора», де було визнано можливість практичного застосування в майбутньому окремих заходів та пропозицій щодо введення на підприємство власного автопарку та впровадження додаткових інформаційних систем (акт впровадження №18/24 від 9 квітня 2018 року).
Апробація результатів представлена у:
1) Стаття «Управління транспортно-експедиторською діяльністю підприємства» у збірнику наукових праць «Сучасні підходи до управління підприємством»;
2) Тези «Управління транспортно-експедиторською діяльністю підприємства» у збірнику тез IX Всеукраїнської науково-практичній конференції «Сучасні підходи до управління підприємством»;
3) Тези «Формування логістичного менеджменту транспортно-експедиційних послуг підприємства», участь у VIII Всеукраїнської науково-практичній конференції «Сучасні підходи до управління підприємством».Master's dissertation on the theme: «Management of transport and forwarding activity of the enterprise (for example, «Sandora»)» contains 119 pages, 17 tables, 13 figures, 2 applications. The list of references has a 35 denomination. The urgency of the theme is due to the constant development of logistics processes and the opportunity to increase the competitive position of the enterprise through the improvement of transport and forwarding activities. The master's dissertation for obtaining the master's degree was carried out at the National Technical University of Ukraine «Kyiv Polytechnic Institute named after Igor Sikorsky» in accordance with the research plans of the Department of Management on the topic «Improvement of the processes of management of logistic systems of Ukrainian enterprises in the conditions of integration into the world economy» (№ ДР 0117U005641). The purpose of the work is to: expand and deepen the theoretical provisions on the management of freight forwarding activities, as well as the disclosure of methods for assessing the effectiveness of this activity at an industrial enterprise. The purpose of the research is determined by the decision of the following tasks: – to consider the essence and basic theoretical principles for the management of freight forwarding activities; - to perform diagnostics of the functioning of the juice industry; – to substantiate the essence of the logistic approach in the management of freight forwarding activities and to determine the main methods for assessing the efficiency of transport and forwarding activities management; – to analyze and perform the characteristics of the field of forwarding activities; – to diagnose the activity of the selected enterprise in the field of providing forwarding services; – to evaluate the efficiency of management of forwarding activity at «Sandora» and to offer ways of improvement; – to substantiate expediency of directions of improvement of the system of management of transport and logistic activity on «Sandora». The object of the research is the process of managing the transport and forwarding activities of the enterprise. The subject of the study is theoretical and methodological aspects and practical tools for managing the transport and forwarding activities of the enterprise. In master's work, a set of general and specific scientific methods, such as a systematic approach, methods of economic and statistical analysis, grouping, graphical modeling of organizational structures, expert evaluation were used. For obtaining analytical information, statistical reporting data, internal, in particular, financial statements of enterprises and materials of practicing specialists in the field of management and logistics were placed in textbooks and electronic sources. The scientific novelty of the research is to: – deepen and refine the existing theoretical foundations on the management of transport and forwarding activities of the enterprise; – systematization of an estimation of efficiency of methods of management of transport and forwarding activity; – new solutions for the organization of transport and forwarding activities are proposed; – the problems of transport expenses management were revealed and summarized; – the proposed decision on optimization of transport costs and reduction of delivery time of the transport and logistics department of the enterprise. The practical significance is the development of methods for optimizing logistics costs for wages, namely, the additional payment for overtime work of drivers and forwarders, as well as the reduction of fixed costs for the payment of hired transport by creating a fleet of cars. The developed program for improving the work of transport and forwarding activities will help to improve the quality of services provided and to strengthen the competitive position in the market. The recommendations and proposals for improving the mechanism of transport and forwarding activity developed in the master's thesis for the master's degree were presented to the Board of Directors of «Sandora», which recognized the possibility of practical application in the future of certain measures and proposals for the introduction of the company's own fleet and implementation additional information systems (implementation act №18/24 from 09.04.18). Approbation of the results is presented in: 1) Study «Management of transport and forwarding activities of the enterprise» in the collection of scientific works «Modern approaches to enterprise management»; 2) The thesis «Management of transport and forwarding activity of the enterprise» in the collection of abstracts of the IX All-Ukrainian scientific-practical conference «Modern approaches to enterprise management»; 3) The thesis «Formation of logistics management of transport and forwarding services of the enterprise», participation in the VIII All-Ukrainian scientific-practical conference «Modern approaches to enterprise management».
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Левус, Яна Олександрівна. "Організація транспортно-експедиційної діяльності підприємства". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/35462.
Повний текст джерелаАнотація:
Дипломна робота на тему: «Організація транспортно-експедиційної діяльності підприємства» містить 100 сторінок, 26 таблиць, 20 рисунків, 2 додатки. Перелік посилань нараховує 30 найменувань.
Метою роботи є аналіз, обгрунтування та розроблення практичних рекомендацій щодо удосконалення організації транспортно-експедиційної діяльності підприємства.
Об’єктом дослідження є процес організації транспортно-експедиційної діяльність підприємства.
Предметом дослідження є теоретичні аспекти та практичні положення стосовно удосконалення транспортно-експедиційної діяльності компанії в сучасних умовах.
База дослідження – ТОВ «Рабен Україна».
Методи дослідження. Виконання дипломної роботи першого (бакалаврського) рівня вищої освіти здійснено при застосуванні загальних та спеціальних методів дослідження: статистичний аналіз, порівняльний аналіз, економічний аналіз – для дослідження стану підприємства та його динаміки, систематизація та узагальнення, SWOT-аналіз та метод «мозкового штурму». У процесі досліджень було використано інформаціїйні технології: Microsoft Excel.
Результати роботи. За результатами проведеного дослідження розроблено та запропоновано проект, що передбачає розширення власного парку транспортних засобів підприємства, з метою зменшення рівня впливу ризиків, пов’язаних із залученням до роботи підрядників – сторонніх транспортних компаній. Це також забезпечить оптимізацію витрат компанії – економічний ефект складе 6314,68 тис.грн щорічної економії. Також запропонована система критеріїв для вибору перевізника, що теж орієнтована на скорочення рівня впливу ризиків на ефективність діяльності підприємства.
Рекомендації щодо використання результатів роботи. Отримані результати дослідження можуть бути використані вітчизняними підприємствами логістичної галузі, для оптимізації витрат на логістичне обслуговування, зокрема ТОВ «Рабен Україна», скорочення рівня впливу ризиків та розширення обсягів діяльності.
Результати впровадження досліджень. Розроблені в дипломній роботі пропозиції були представлені на розгляд керівному складу ТОВ «Рабен Україна», де було визнано ефективність їх практичного застосування.Barchelor`s thesis includes 100 pages, 26 tables, 20 drawings, 2 attachments. The bibliography list includes 30 items. The purpose of the work is the analysis, substantiation and development of practical recommendations for improving the organization of transport and forwarding activities of the enterprise. The object of research is the process of organizing the transport and forwarding activities of the enterprise. The subject of research is the theoretical aspects and practical provisions for improving the freight forwarding activities of the company in modern conditions. The base of the study is Raben Ukraine LLC. Research methods. Thesis of the first (bachelor's) level of higher education was carried out using general and special research methods: statistical analysis, comparative analysis, economic analysis - to study the state of the enterprise and its dynamics, systematization and generalization, SWOT-analysis and "brainstorming". Information technology which was used for the research: Microsoft Excel. Results of work. Based on the results of the study, a project, which was proposed, provides for the expansion of its own fleet of vehicles, in order to reduce the impact of risks associated with the involvement of contractors - third-party transport companies. It can also optimize the company's costs - the economic effect will be 6314.68 thousand UAH. A system of criteria for carrier selection is also proposed, and is focused on reducing the level of risk impact on the efficiency of the enterprise. Recommendations about the usage and application of the results of work. The results of the study can be used by domestic enterprises of the logistics industry to optimize the cost of logistics services, in particular LLC "Raben Ukraine", reduce the level of risk and expand the scope of activities. The results of research implementation. The proposals developed in the thesis were presented to the management of Raben Ukraine LLC, where the effectiveness of their practical application was recognized.
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Česnulevič, Jelena. "Ekspedicinės ir kelių transporto įmonės veiklos efektyvumo lyginamasis tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090626_101620-28085.
Повний текст джерелаАнотація:
Šio darbo tikslas – atlikti ekspedicinių ir transporto įmonių veiklos efektyvumo lyginamąjį tyrimą. Tyrimui turi įtakos esama situacija transporto sektoriuje, todėl darbe įvertinamos kelių transporto sektoriaus plėtros perspektyvos bei analizuojamos krovinių vežimo apimtys per pastaruosius 5 metus. Darbe remiamasi apklausoje dalyvavusių respondentų atsakymais apie jų įmonių veiklos efektyvumą. Atlikus tyrimą buvo nustatyta, kad ekspedicinė veikla (dabartinėmis sąlygomis) yra efektyvesnė, nei vežimo. Tam turėjo įtakos tai, kad 2008 metai buvo nuostolingi vežėjams, nes didėjo degalų kainos bei mažėjo krovinių vežimo apimtys. Remiantis respondentų atsakymais, galima teigti, kad transporto veikla tampa mažiau pelninga, nes beveik pusė jų, jeigu tektų rinktis iš naujo, kuo užsiimti, pasirinktų kitą veiklą. Kita dalis respondentų nurodė, kad užsiimtų ekspedijavimu. O tai reiškia, kad ekspeditorių padėtis yra lengvesnė nei vežėjų. Tik maža dalis apklaustųjų pasirinktų vežimo veiklą. Darbą sudaro 5 dalys: įvadas, analitinė-metodinė dalis, eksperimentinė-tiriamoji dalis, išvados ir siūlymai, literatūros sąrašas. Darbo apimtis – 81 p. teksto be priedų, 13 iliustracijų, 3 lentelės, 52 bibliografiniai šaltiniai.The aim of this work - to perform comparative analysis of forwarding and transportation companies activity efficiency. The present situation in the transport sector has influence upon the analysis, therefore in the work, the perspectives of road transport sector expansion are evaluated, also cargo transportation volumes during the latter 5 years are analyzed. The work is based on the answers of the respondents, who participated in the survey - about the efficiency of their companies' activity. When the analysis was made, it was established, that the forwarding activity (in the present circumstances) is more effective than the transportation activity. Also this fact, that the year 2008 was loss-making to the carriers, because the fuel prices increased and the volumes of cargo transportation decreased, had influence on the research results. On the grounds of respondent answers, it can be stated, that transportation activity becomes less profitable, because nearly half of the respondents, if they had a possibility to choose newly what activity to take, would choose the other activity. Other part of the respondents has indicated that they would use forwarding. And this means, that the condition of forwarders is easier than the carriers' condition. Only the little part of the respondents would choose the carrier activity. The work is made from 5 parts: introduction, analytical-methodical part, experimental-investigative part, conclusions and suggestions, list of literature. The... [to full text]
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Ermolaev, Andrey. "Efficiency Of Road Transport Intermediaries In International Trade." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-205783.
Повний текст джерелаАнотація:
The thesis is to provide comprehensive efficiency analysis of road transport intermediaries in terms of international trade between the Commonwealth of Independent States and the European Union. The analysis establishes particular patterns and provides solutions of how to increase financial effectiveness of the supply chain in case freight forwarding companies are involved in the process.
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Herain, Jan. "Využití železniční přepravy jako alternativy k námořní přepravě z pohledu zasilatelské společnosti." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-205700.
Повний текст джерелаАнотація:
This thesis addresses various concerns of maritime and rail transport of goods between East Asia and the Czech Republic. Its conceptual part outlines the present situation of sea freight transportation with the emphasis on the container use. Furthermore, the thesis describes the rail infrastructure between East Asia and Europe. In the how-to part, the author describes working procedures of an actual freight forwarding company carrying out an import shipment from China into the Czech Republic, utilising ocean and rail carriers. The last part of the thesis contains a summary of the main differences when employing various types of transport, and of their comparison based on the time of the shipment and on its cost.
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Jordan, Fiona Lya. "Bacterial transport, distribution and activity in porous media." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284093.
Повний текст джерелаАнотація:
Understanding the extent of microbial transport, distribution and activity in the subsurface is paramount for effective in-situ bioremediation. In one study, we investigated the impact a substrate pulse has on the movement of inoculated or indigenous bacteria through saturated porous media. In another study, we developed a method to visualize the distribution of bacteria on soil surfaces. The elution of either inoculated or indigenous bacteria was monitored from model (homogenous) sand or natural (heterogenous) soil column systems. Sand columns receiving salicylate resulted in enhanced elution of inoculated P. putida. However, the salicylate pulse did not result in enhanced elution of P. putida from a natural system. For natural heterogenous systems, the salicylate pulse significantly affected the elution of certain indigenous bacteria. Specifically, more heterotrophs were eluted from soil columns receiving salicylate than from those that did not for both loamy sand soils tested. On the other hand, there were consistently fewer salicylate-degrading cells eluted in the presence of salicylate from one of the two soils tested. These data suggest that bacterial transport is a function of both the porous medium and the microbial population(s) under investigation. In the second study, an agar lift-DNA/DNA hybridization technique was developed to visualize the distribution of eubacteria on soil surfaces. Briefly, a single layer of soil was lifted from the surface of soil microcosms onto agar slabs and allowed to incubate. Bacterial colonies were lifted from the agar slabs onto membranes. The location of individual colonies was detected on the membranes by hybridization with a probe complementary to a conserved region of the eubacterial genome. This method was able to detect active microorganisms on different soil surfaces. The probe signal correlated well with the number of metabolically active microorganisms found in soils amended with a carbon source. This technique also allowed for visualization of localized microbial activity. A combined approach utilizing both soil column studies and the agar-lift technique should allow researchers to better elucidate microbial transport, distribution and activity in subsurface environments.
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Reis, Gerald Feliz. "Mechanisms of motor activity regulation in axonal transport." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3315202.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed Nov. 5, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Karlsson, Jonas. "Improving TCP Performance in Wireless Multi-hop Networks : Design of Efficient Forwarding and Packet Processing Techniques." Licentiate thesis, Karlstads universitet, Avdelningen för datavetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-6820.
Повний текст джерелаАнотація:
Due to the high availability of cheap hardware, wireless multi-hop networks and in particular Wireless Mesh Networks (WMNs) are becoming popular in more and more contexts. For instance, IEEE 802.11 based WMNs have already started to be deployed as means to provide Internet access to rural areas in the developing world. To lower the cost and increase the coverage in such deployments, the wired network is extended with a wireless backbone of fixed mesh routers. With advances in technology and reduction in price comes also the possibility for more powerful wireless nodes, having multiple radios that allow transmitting on different channels in parallel. To be a successful platform for providing general Internet access, wireless multi-hop networks must provide support for common Internet applications. As most of the applications in the Internet today use the Transmission Control Protocol (TCP), TCP performance is crucial. Unfortunately, the design of TCP’s congestion control that made it successful in today’s Internet makes it perform less than optimal in wireless multi-hop networks. This is due to, among others, TCP’s inability to distinguish wireless losses from congestion losses. The current trend for operating system designers is also to focus TCP development on high-speed fixed networks, rather than on wireless multi-hop networks. To enable wireless multi hop networks as a successful platform there is therefore a need to provide good performance using TCP variants commonly deployed in the Internet. In this thesis, we develop novel proposals for the network layer in wireless multi-hop networks to support TCP traffic more efficiently. As an initial study, we experimentally evaluate different TCP variants, with and without mobile nodes, in a MANET context. Our results show that TCP Vegas, which does not provoke packet loss to determine available bandwidth, reduces the stress on the network while still providing the same or slightly increased performance, compared to TCP Newreno. We further propose and evaluate packet aggregation combined with aggregation aware multi-path forwarding to better utilize the available bandwidth. IP layer packet aggregation, where small packets are combined to larger ones before sent to the link layer, has been shown to improve the performance in wireless multi-hop networks for UDP and small packet transfers. Only few studies have been made on the impact of packet aggregation on TCP traffic, despite the fact that TCP traffic constitutes the majority of the Internet traffic. We propose a novel aggregation algorithm that is specifically addressing TCP relevant issues like packet reordering, fairness and TCP timeouts. In a typical WMN scenario, the aggregation algorithm increases TCP performance by up to 70 % and decreases round trip time (RTT) by up to 40 %. A detailed evaluation of packet aggregation in a multi radio setting has shown that a naive combination of multi path routing and packet aggregation can cause valuable aggregation opportunities to be lost. Therefore, we propose a novel combined packet aggregation and aggregation aware forwarding strategy that can reduce delay, packet loss and increase TCP performance by around 30 %.
9
Loiseau, Philippe. "Intracellular transport : regulation of kinesin activity and cargo recognition." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608412.
Повний текст джерела
10
Hathway, Elizabeth Abigail. "CFD modelling of pathogen transport due to human activity." Thesis, University of Leeds, 2008. http://etheses.whiterose.ac.uk/11284/.
Повний текст джерелаАнотація:
Health-care Associated Infection is a major concern with 1 in 11 patients affected each year. There is evidence that some pathogens may be transported by an airborne route, and hence fluid modelling tools, such as Computational Fluid Dynamics (CFD), are increasingly used to aid understanding of the transport mechanisms of infection. These models tend to only consider respiratory infections that are released from a single point, such as a person coughing. However there is substantial evidence that certain pathogens, such as MRS A, may be released from the skin during regular routine activities (e.g. undressing, walking). An observational and air sampling study carried out on a respiratory ward found that certain activities correlated to greatly increased numbers of large particles ( > 5µm), and bioaerosols. The increased concentrations of bioaerosols also corresponded to sampling of potentially pathogenic Staphylococcus aureus. It is therefore necessary to be able to represent these releases ofbioaerosols within CFD models used in design and risk assessment. Bioaerosol transport is modelled in CFD simulations usmg passive scalar transport and Lagrangian particle tracking models with the DRW model to simulate turbulent diffusion. These are validated for the first time using spatial variation of airborne and deposited bioaerosols generated under controlled conditions. Simpler multi-zone models are compared to CFD and found to perform well at simulating the bioaerosol decay within large spaces that can be assumed to be well mixed, however they are not refined enough to simulate the detail required to study the transfer of infection between individual patients. A zonal source model is introduced and validated with the aim of representing the time average dispersion from a transient source in a steady state model. This enables the dispersion of bioaerosols from activities occurring in hospital wards to be represented within CFD models. The zonal source model is shown to give a good representation of the average dispersion and total deposition of a transient source, whereas a point source is not. Point sources produce different dispersion patterns to zonal sources and so it is recommended that both are used to simulate bioaerosols produced due to activities or respiratory diseases. Point sources are found to be highly sensitive to the injection position, whereas the zonal source is found to produce relatively similar patterns of dispersion for varying size definitions. CFD is a useful tool for studying pathogen transport in indoor spaces, and when doing so it is recommended that the potential bioaerosol release from the skin is considered which can be taken into account within a steady state model using a zonal source model.
11
Werner, Ursula. "Microbial activity and transport processes in near-shore, permeable sediments." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979757169.
Повний текст джерела
12
Harper, Mary Ellen. "Ion transport and brown adipose tissue activity in energy balance." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7486.
Повний текст джерелаАнотація:
The objective of this work was to study the activity of the Na$\sp+$,K$\sp+$ pump and the thermogenic activity and capacity of brown adipose tissue (BAT) under conditions of dietary energy deficit and surfeit in both human subjects and laboratory animals. While controversial, it had earlier been hypothesized that Na$\sp+$,K$\sp+$ pump activity (1) acts as a "metabolic pacemaker" in the control of cellular energy expenditure, and (2) "adapts" during undernutrition so that overall energy expenditure is decreased. That BAT thermogenic activity increases during overfeeding and decreases during undernutrition is well recognised; BAT thermogenesis has hence been proposed as an "energy buffer" mechanism. However, at the outset of this work the effectiveness of dietary saturated fat in the induction of BAT thermogenesis was controversial. The first sections of this thesis describe the effects of undernutrition and nutritional rehabilitation upon Na$\sp+$,K$\sp+$ pump activity in erythrocytes of children with cerebral palsy (CP). The results show that, unlike results from developing world undernourished children, erythrocyte Na$\sp+$,K$\sp+$ pump activity was not lower in cells from the undernourished children with CP. The later sections describe the simultaneous study of both Na$\sp+$,K$\sp+$ pump and BAT activities during diet-induced obesity (DIO) and dietary restriction (DR) in rats. I hypothesized that both mechanisms might act as "energy buffers" and contribute to metabolic adaptation during DIO and DR. The effects of lard- and tallow-based diets were studied. The extent of DIO was assessed using total body electrical conductivity (TOBEC), carcass analysis and fat pad weights; it was concluded that presently available TOBEC equipment is unsuitable for serial determinations of rat adiposity, and that fat pad weights are good estimates of adiposity. Na$\sp+$,K$\sp+$ pump activity increased in thymocytes of rats fed the high saturated fat diets; activity decreased in erythrocytes and hepatocytes in some groups following DR. BAT activity and thermogenic capacity were enhanced by high saturated fat diet-feeding; activity decreased following DR. Lard- and tallow-based diets had differing effects upon the extent and the timing of changes in the activities of the two mechanisms. Despite increases in Na$\sp+$,K$\sp+$ pump and BAT activities, basal metabolic rate (BMR) was not increased in the obese rats; decreases did however occur following DR. Diet-induced alterations in both mechanisms could occur through common pathways such as sympathetic neural activity and/or thyroid hormones. Increases in plasma T$\sb3$ concentrations were associated with high saturated fat diet feeding as were decreases with DR. It is concluded that the alterations in both mechanisms are compatible with the hypothesis that these mechanisms function as energy buffer mechanisms during dietary energy surfeit and deficit.
13
Keen, Heidi A. "Activity of group-transported horses during onboard rest stops." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4708.
Повний текст джерелаАнотація:
Activity of group-transported horses was evaluated during onboard rest stops to
determine if horses derive meaningful rest. A single-deck semi-trailer separated into
three compartments was used for all shipments. In Experiment One, twelve video
cameras were used to record behavior of horses during five, 16 to 20 h shipments, with a
high (397.44kg/m2), medium (348.48 kg/m2) and low (220.91 kg/m2) density group in
each shipment. One-hour rest stops occurred after 8 h of transport and prior to unloading,
during which two groups were provided water. Movement of each horse visible on video
was quantified by counting the number of times the head crossed the vertical and/or
horizontal axes of the body at the withers. Mean number of movements per 5-min
interval in each group (n=13) was used to compare effects of density, access to water, and
order of stops. The high and low-density watered groups had increased activity during
the first 10 min of both rest stops potentially due to maneuvering for access to water. The
medium-density watered groups had increased activity during the first 10 min of only the
second rest stop. Activity slightly increased in the medium and low-density groups after
55 min possibly indicating adequate rest, but a similar increase did not occur in highdensity
groups. In Experiment Two, two shipments, lasting 23 h and 24 h respectively,
consisted of three groups of horses loaded at high density (397.32 kg/m2). Ninety-minute
rest stops occurred after every 6 h of transport and prior to unloading for a total of three rest stops. Percentage of visible horses "active" was averaged across each 5-min interval
of the stop. Activity was highly variable within and between shipments. Activity was
high at the beginning of stops one and three of Shipment One. A similar but less
dramatic settling occurred at the start of all three rest stops in Shipment Two. Twenty
three of thirty-four noted increases in alertness were due to aggression or noises outside
the trailer. In both experiments horses remained active during all stops indicating fatigue
had not become a major factor in these studies.
14
Billerbeck, Markus. "Pore water transport and microbial activity in intertidal Wadden Sea sediments." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979768713.
Повний текст джерела
15
Kamruzzaman, Md. "Examination of Activity Spaces Identifying Transport Disadvantage in Rural Northern Ireland." Thesis, University of Ulster, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.523149.
Повний текст джерела
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Cain, Natalie E. (Natalie Elaine). "Transport activity dependent regulation of the yeast general amino acid permease." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62612.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
The general amino acid permease Gap1p of Saccharomyces cerevisiae scavenges amino acids from the extracellular medium for use as nitrogen sources in starvation conditions. Because unlimited uptake of both naturally occurring amino acids and amino acid analogs is toxic, Gap1p is active at the plasma membrane only when amino acid levels are low. Gap1p is down regulated when amino acids are abundant by two distinct post-translational mechanisms. Gap1p is regulated post-translationally to respond quickly and efficiently to changing amino acid concentration. An increase in amino acids causes accumulation of Gap1p in the vacuole and inactivation of Gap1p located at the plasma membrane. Conversely, a decrease in amino acid levels allows for redistribution of Gap1p from internal membranes to the cell surface. Here I examine the mechanism of amino acid regulation of Gap1p. Previous studies of Gap1p sorting have focused on the trans-acting factors required for the distribution of Gap1p between the plasma membrane and internal compartments. To complement this body of work, these studies focus on the cis-elements required for Gap1p sorting. We find that post-translational regulation of Gap1p requires the catalytic activity of Gap1p, indicating that sorting and activity of Gap1p are controlled in cis. Gap1p therefore can serve as an amino acid sensor to control its activity in response to nutrient levels. This finding suggested that post-translational regulation of Gap1p could apply to other transporter proteins in yeast. I examined the activity and localization of a related transporter protein, the histidine-specific permease Hip1p in response to various amino acids, and found that although Hip1p is down regulated only in response to histidine, this regulation is less tightly controlled than the regulation of Gap1p. This observation supports previous assertions that the function of Gap1p in the cell is distinct among yeast amino acid transporters.
by Natalie E. Cain.
Ph.D.
17
Hrizi, Fatma. "Mécanismes de contrôle pour les applications coopératives de sécurité routière dans les systèmes de transport intelligents." Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00998531.
Повний текст джерелаАнотація:
Dans ces dernières années, les Systèmes de Transport Intelligents (STI) ont été considérés comme l'un des domaines de recherche les plus émergents en raison de leur rôle prometteur dans l'amélioration de la gestion du trafic et de la sécurité routière. Les applications coopératives de sécurité, étant les plus cruciales, ont gagné beaucoup d'intérêt. L'efficacité de ces applications dépend largement de l'échange efficace de deux principaux types d'informations. L'information de localisation périodique correspondant à l'information de localisation du voisinage et l'information événementielle qui est transmise en multi-sauts et générée lors de la détection d'une situation d'urgence. En raison de la caractéristique à grande échelle des STI, cette information fait l'objet du problème de congestion dans le réseau. L'objectif de cette thèse est d'assurer un contrôle fiable et robuste des informations de sécurité permettant de réduire la congestion du canal tout en tenant en compte des exigences des applications de sécurité. Nous examinons la diffusion de l'information événementielle en proposant une approche a multi-sauts qui a montré une amélioration de la réception de l'information. Cependant, cette approche reste très sensible à la charge de canal résultant de transmissions de l'information de localisation périodiques. D'autre part, la transmission efficace de l'information événementielle repose essentiellement sur la détection précise des événements de sécurité et en conséquence sur la précision de l'information de localisation. Ainsi, nous proposons un mécanisme de contrôle de l'information de localisation afin de fournir une meilleure précision et limiter la charge du canal. Les approches proposées dans cette thèse ont profondément étudié le compromis entre le respect des exigences des applications de sécurité et la gestion efficace de la congestion dans le réseau véhiculaire.
18
Virtanen, I. (Iiro). "Surface flux transport simulations of the photospheric magnetic field." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526223292.
Повний текст джерелаАнотація:
Abstract This thesis studies the long-term evolution of the photospheric magnetic field using surface flux transport simulations. The photospheric magnetic field and magnetic activity are tightly connected to space weather, and affect the whole heliosphere including the Earth. However, due to a lack of reliable observations our understanding of the long-term evolution of the photospheric magnetic field is still poor. Surface flux transport models, which are capable of simulating the evolution of the whole surface field from observations of solar activity, can be used to study the field in times when direct observations are not available. In this thesis we validate our surface flux transport model, optimize its parameters and test its sensitivity to uncertainties in parameter values and input data. We find a need to extend the model with a decay term to properly model the deep and long minimum between solar cycles 23 and 24, and simulate the photospheric magnetic field of cycles 21–24 using magnetographic observations as input. We also study consequences of hemispherically asymmetric activity, and show that activity in one hemisphere is enough to maintain polar fields in both hemispheres through cross-equatorial flow of magnetic flux. We develop a new method to reconstruct active regions from calcium K line and sunspot polarity observations. We show that this reconstruction is able to accurately capture the correct axial dipole moment of active regions. We study the axial dipole moments of observed active regions and find that a significant fraction of them have a sign opposite to the sign expected from Hale’s and Joy’s laws, proving that the new reconstruction method has an advantage over existing methods that rely on Hale’s and Joy’s laws to define polarities. We show one example of a long simulation covering solar cycles 15–21, demonstrating that using the active region reconstruction and surface flux transport model presented in this thesis it is possible to simulate the large-scale evolution of the photospheric magnetic field over the past centuryOriginal papers The original publications are not included in the electronic version of the dissertation. Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., Yeates, A., & Mursula, K. (2017). Reconstructing solar magnetic fields from historical observations. II. Testing the surface flux transport model. Astronomy & Astrophysics, 604, A8. https://doi.org/10.1051/0004-6361/201730415 http://jultika.oulu.fi/Record/nbnfi-fe2017103050356 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., & Mursula, K. (2018). Reconstructing solar magnetic fields from historical observations. III. Activity in one hemisphere is sufficient to cause polar field reversals in both hemispheres. Astronomy & Astrophysics, 616, A134. https://doi.org/10.1051/0004-6361/201732323 http://jultika.oulu.fi/Record/nbnfi-fe201902205813 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., Bertello, L., Yeates, A., & Mursula, K. (2019). Reconstructing solar magnetic fields from historical observations. IV. Testing the reconstruction method. Astronomy & Astrophysics, 627, A11. https://doi.org/10.1051/0004-6361/201935606 http://jultika.oulu.fi/Record/nbnfi-fe2019091828628 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., & Mursula, K. (2019) Axial dipole moment of solar active regions in cycles 21-24. Manuscript
19
Whitehead, Tim. "The links between transport charging, economic activity and business : an economic geography." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397473.
Повний текст джерела
20
Blenkinsopp, Sandra Anna. "The ultrastructure, storage products and electron transport system activity of river biofilms." Thesis, Bangor University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.480561.
Повний текст джерела
21
Mares-Samano, Sergio. "In silico design of potential modulators of ABCB1 and ABCG2 transport activity." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525902.
Повний текст джерелаАнотація:
Molecular modelling techniques were implemented to identify potential modulators of ABCB1 and ABCG2 targeted to the nucleotide-binding domains (NBDs) and to predict, at the molecular level, putative mechanisms of ligand-transporter interaction. Three-dimensional models of the NBDs of ABCB1 and ABCG2 were constructed by homology modelling. Stereochemical robustness and functional validity of models were demonstrated by accurately correlating the docking characteristics of a series of flavonoids and steroids with the findings of reported in vitro functional studies. Homology models were subsequently used to identify potential modulators targeted to the NBDs of ABCB1 and ABCG2 by virtual screening of the diversity set II database of the National Cancer Institute. Based on predicted affinity and binding orientation within the ATP-binding pocket of NBDs, compounds possessing predicted high binding affinity were successfully identified. Homology models of the NBDs of ABCB1 and ABCG2 were also employed for de novo design of potential modulators. Based on the three-dimensional structures of NBDs, and using flavonoid-frames as 'seed structures', a chemically unique set of molecules with a predicted high affinity to the ATP-binding pockets of both transporters, was constructed. In addition to homology models of the NBDs, a stereochemically robust three-dimensional atomic model of human ABCB1 was constructed by homology modelling using the recently elucidated high-resolution structure of mouse ABCB1 as template. Interactions between human ABCB1 and a number of substrates and inhibitors were investigated employing in silico docking studies. Predicted docking conformations of substrates/inhibitors within human ABCB1 suggest the existence of multiple binding sites located mainly in the vicinity of the internal cavity.
22
Birch-Machin, M. A. "ATPase activity and Ca#2#+ transport properties of rat liver plasma membranes." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376077.
Повний текст джерела
23
Borys, Philippe. "Activity removal and transport studies in support of PWR in-pile operations." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13363.
Повний текст джерела
24
Marar, Jose Ricardo. "Assessing the implementation of supranational regulatory activity in the road freight sector." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271634.
Повний текст джерела
25
Vladyka, Yuliia, and Maria Savytska. "Investment mechanism for air transport financing in Ukraine." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/54647.
Повний текст джерелаАнотація:
1. "Інвестиційні механізми структурних трансформацій у транспортній
галузі". Аналітична записка | National Institute for Strategic Studies
[Електронний ресурс] / 1 – Режим доступу до ресурсу:
https://niss.gov.ua/en/node/1038.
2. Financing for aviation infrastructure ICAO [Tktrnhjyybq htcehc] | 1 –
Ht;bv ljcnege lj htcehce^ https^||www/un/org|esa|ffd|wp-
content|uploads|2016|01|Financing-for-aviation-infrastructure_ICAO_IATF-Issue-
brief/pdf/One of the tasks of modernization of Ukraine's economy is to create favorable real conditions and their opportunities for the development of transport and transit potential of Ukraine on the basis of investment development. Intensifying the use of external and internal investment resources allows for structural transformation in the transport sector and the implementation of strategically important projects aimed at upgrading transport infrastructure and ensuring high standards of transport services.
26
Sůva, Lukáš. "Námořní kontejnerová přeprava mezi Čínou a Evropou na příkladu firmy DB Schenker." Master's thesis, Vysoká škola ekonomická v Praze, 2017. http://www.nusl.cz/ntk/nusl-264558.
Повний текст джерелаАнотація:
The goal of this diploma thesis is to define the maritime container transport and some of the important aspects, which are closely related to it. The next goal is to describe the single steps of the maritime container transport (LCL) from port in Hong Kong, to compare import of LCL consignment from port in Hong Kong or port in Nansha and to decide which of these option is better for the customer in Czech republic, speaking of time and cost view. This goal is shown on the specific business case in DB Schenker company.
27
Blom, Kajsa, and Linnéa Håcansdotter. "Time and Activity Analysis of Doctors and Nurses Work Assignments." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121684.
Повний текст джерелаАнотація:
I och med människornas ökade livslängd har kraven på sjukvården ökat, samtidigt finns det en bristande tillgång på vårdpersonal. Genom att öka antalet arbetsuppgifter för sjukvårdspersonalen som är värdeskapande för patienten kan sjukvården svara på kraven, då sjukvårdens befintliga resurser kan användas på ett mer effektivt sätt. Utifrån observationer och tidmätningar som har utförts på Vrinnevisjukhusets vårdavdelning (AVD1) för stroke och rehabilitering av stroke, har detta examensarbete kunnat ge förslag på förbättringsområden som kan effektivisera och öka antalet värdeskapande arbetsuppgifter för läkarna och sjuksköterskorna. Utifrån tidmätningarna skapades även en tidfördelning av läkarnas respektive sjuksköterskornas arbetsuppgifter på AVD1, och visade att en läkare och sjuksköterska på AVD1 spenderade mest tid på administrativa arbetsuppgifter (48 % för läkare och 26 % för sjuksköterskor), kommunikation (15 % för läkare och 24 % för sjuksköterskor) patienttid (15 % för läkare och 20 % för sjuksköterskor). De största förbättringsområdena av både läkarnas och sjuksköterskornas arbetsuppgifter som identifierades utifrån observationerna och resultatet av tidfördelning var att bristen på riktlinjer för införandet av journalanteckningarna ineffektiviserade deras administrativa arbetsuppgifter, samt att saknaden av ett system för läkemedelssaldo försvårade sjuksköterskornas läkemedelshantering. För att åtgärda problemen bör AVD1 och hela medicinkliniken som AVD1 ingår i, fastställa riktlinjer för hur inskrivning av information i journal skall genomföras för att undvika dubbelarbete och underlätta informationssökningen. Medicinkliniken bör även investera i ett nytt lagersystem som uppdaterar saldot för läkemedel automatiskt, där det också går att utläsa hur mycket av varje läkemedel som finns på respektive avdelning och i respektive lager. Övriga förbättringsområden som identifierades för läkarna och sjuksköterskorna på AVD1 var att placeringen av utrustning och verktyg på AVD1 kan förbättras med hjälp av Leans 5S, samt att genom planering och tydligöring att rapportering pågår kan läkare och sjuksköterskor minska på sysslolöshet och antalet gånger de blir avbrutna under en arbetsuppgift. AVD1 skulle även kunna öka en läkares respektive sjuksköterskas värdeskapande arbetsuppgifter genom att uppdatera datorerna, samt omplacera eller investera i fler skrivare och telemetridatorer.With people’s increased life span, the demand for health care services has increased, while there is a lack of health care professionals. By increasing the health care professionals’ value-adding work assignments for patient care, they will be used more efficiently and be able to meet the demand of the health care services. Based on observations and time studies carried out at Vrinnevisjukhusets health care facility for stroke and rehabilitation of stroke, this thesis has provided suggestions for areas of improvement which could increase the amount of doctors’ and nurses’ value-adding work assignments. Based on the result time studies at the health care facility, a time distribution of the doctors’ and nurses’ work assignments was also established and showed that they spent their most time on administrative work (48 % for doctors and 26 % for nurses), communication (15 % for doctors and 24 % for nurses) and time with patient (15 % for doctors and 20 % for nurses). Based on the observations and the result of time distribution, the doctors and nurses main areas of improvement was the lack of guidelines for implementation of journal notes which made their administrative work assignments inefficient, as well as the lack of system for the stock levels of medicines, which hindered the nurses’ medication management. To address these problems the health care facility and the entire medical clinic that the facility is part of, should determine guidelines on how the journal notes should be conducted for avoidance of duplications and to also facilitate the search of information. The medical clinic should also invest in a new storage system which updates the stock levels of medicines automatically, and also makes it possible to see how much of each medicine is available in each facility and storage. The arrangement of the facilities storage is also an area that could be improved by implementing the Leans’ 5S, which would improve the doctors’ and nurses’ time distribution and increase the value-adding work assignments. By also planning and clarify when a reporting is ongoing, as well as relocate or invest in more printers and telemetry computers, the facilities doctors’ and nurses’ time distribution will be improved and also increase the amount of work assignments that is value-adding.
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Barber, Latorya Arnold. "The Activity of Lipid Transport Proteins in Normal and Sickle Red Blood Cells." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1243353188.
Повний текст джерела
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Darweesh, Ruba. "IN VITRO LUNG EPITHELIAL CELL TRANSPORT AND ANTI-INFLAMMATORY ACTIVITY FOR LIPOSOMAL CIPROFLOXACIN." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/577.
Повний текст джерелаАнотація:
Liposomal ciprofloxacin (Lipo-CPFX) is being developed for inhalation, with a goal of sustaining the therapeutic activity, compared to unformulated ciprofloxacin (CPFX). However, the kinetics and mechanism of its sustained local lung retention and pharmacological activity are yet to be fully characterized. This project hypothesized that Lipo-CPFX enables slower and sustained lung epithelial transport and uptake, compared to CPFX, thereby producing prolonged local pharmacological actions. The human bronchial epithelial Calu-3 cells were used as monolayers to characterize the kinetics and mechanism of transport and/or uptake, and to assess the effects of such slow kinetics for Lipo-CPFX on its inhibition against lipopolysaccharide (LPS)-induced proinflammatory IL-8 release. The transport fluxes for Lipo-CPFX across the highly restricted Calu-3 cell monolayers was transepithelial electrical resistance-independent, which suggested predominant transcellular transport. Compared to CPFX, Lipo-CPFX showed 6-18 times slower transport, while the flux was increased with increasing concentration proportionally without saturation. Its unaltered transport by cellular energy depletion, transport inhibition by a reduced temperature (4 oC) and endocytosis/lipid fusion inhibitors, filipin and LysoPC, and increased transport by excess empty liposomes collectively suggested cell energy-independent, lipid bilayer fusion mechanisms for the Lipo-CPFX transport across the Calu-3 cells. Likewise, Lipo-CPFX showed 2-4 fold lower cellular uptake than CPFX, proportional to concentration. Lipo-CPFX exhibited significant inhibitory activities at ≥ 0.01 mg/mL on LPS-induced IL-8 release from the Calu-3 cells, which was equipotent to CPFX. Upon 24 h pre-incubation, Lipo-CPFX caused 36.9 and 47.5 % inhibition at 0.01 and 0.05 mg/mL, respectively, while CPFX failed to do so. However, the effect was negated upon repeated wash of the mucosal cell surface, speculating the importance of cell membrane-associated drug/formulation on the inhibitory activities for Lipo-CPFX. Upon 24 h transport, Lipo-CPFX retained 79.0 % of the 4 µg dose on the mucosal cell surface, which was 1.9-times greater than 40.7 % for CPFX. As a result, when LPS was added at 24 h of the transport, Lipo-CPFX was still capable of causing 60.1 % inhibition, as its sustained local anti-inflammatory activity; CPFX however also exhibited equipotent inhibition, by virtue of comparable cellular drug uptake/transport.
30
Zetsche, Eva-Maria. "Metabolic activity in intertidal sands : the role of permeability and carbon sources." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59602.
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Vermaak, I., AM Viljoen, JH Hamman, and Vuuren SF Van. "Effect of simulated gastrointestinal conditions and epithelial transport on extracts of green tea and sage." Elsevier, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001730.
Повний текст джерелаАнотація:
A bstract
Few in vitro screening studies on the biological activities of plant extracts that are intended for oral
administration consider the effect of the gastrointestinal system. This study investigated this aspect on
extracts of Camellia sinensis (green tea) and Salvia officinalis (sage) using antimicrobial activity as amodel
for demonstration. Both the crude extracts and their products after exposure to simulated gastric fluid
(SGF) as well as simulated intestinal fluid (SIF) were screened for antimicrobial activity. The
chromatographic profiles of the crude plant extracts and their SGF as well as SIF products were recorded
and compared qualitatively by means of high performance liquid chromatography coupled to mass
spectrometry. The effect of epithelial transport on the crude plant extracts was determined by applying
them to an in vitro intestinal epithelial model (Caco-2). The crude extracts for both plants exhibited
reduced antimicrobial activity after exposure to SGF, while no antimicrobial activity was detected after
exposure to SIF. These results suggested chemical modification or degradation of the antimicrobial
compounds when exposed to gastrointestinal conditions. This was confirmed by a reduction of the peak
areas on the LC–UV–MS chromatograms. From the chromatographic profiles obtained during the
transport study, it is evident that some compounds in the crude plant extracts were either not
transported across the cell monolayer or they were metabolised during passage through the cells. It can
be deduced that the gastrointestinal environment and epithelial transport process can dramatically
affect the chromatographic profiles and biological activity of orally ingested natural products.
32
Garnham-Lee, Katy P. "Predicting physical activity behaviour across early adolescence." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/35275.
Повний текст джерелаАнотація:
Physical activity (PA) has been labelled the miracle drug (Pimlott, 2010) and participating in regular PA has ample physical and mental wellbeing benefits. However, physical inactivity remains a critical public health concern, particularly across adolescence. In England the proportion of adolescents aged 13-15 years meeting the recommended guidelines for PA decreased significantly from those at a younger age (Health and Social Care Information Centre, 2009; 2012; 2015). The adolescent years (13 18 years) have been identified as the age of greatest decline in PA, although it is possible that large declines can also be seen at younger ages (Sallis, 2000). Among girls the decline in PA is greater at younger ages (9 12 years old) and among boys it is greater at older ages (13 16 years old) (Dumith, Gigante, Domingues, & Kohl, 2011). Thus, examining behaviour of early adolescents (aged 11-13 years) is a primary focus of this thesis. Researchers have called for a more comprehensive grasp of PA correlates and determinants and their impact on behaviour (Biddle & Mutrie, 2001, 2008). This broader picture needs to incorporate longitudinal study designs to accurately portray developmental changes (Evenson & Mota, 2011). This thesis aims to work towards a better understanding of associations among variables across aspects of the ecological model in relation to PA behaviour during early adolescence. Early adolescents within their first year of secondary school (year 7, aged 11 12 years) were recruited through schools across the East Midlands, United Kingdom (UK). These participants completed various measures across an 18 month period to compile all data required for the thesis. The thesis begins with a focus on active transport as a means of commuting to school which can significantly contribute to overall PA levels (Aibar, Bois, Generelo, Bengoechea, & Paillard, 2015; Slingerland, Borghouts, & Hesselink, 2012). The distance from home to school is an important influence on the decision to use active transport; however, ecological perspectives would suggest this variable may interact with individual, interpersonal and environmental factors. Therefore, the first study of this thesis investigates whether the relationship between distance to school and active transport is moderated by (i) gender, (ii) biological maturation, (iii) perceived family support for PA and (iv) multiple deprivation. Cross-sectional results from the baseline data collected demonstrated that the relationship between distance to school and the likelihood to actively travel to school is moderated by biological maturation, multiple deprivation and family support of PA in adolescents. Further analysis revealed that late-maturing children, those from less socio-economically deprived backgrounds and children with low family support of PA are less likely to actively commute to school as distance to school increases. Due to the interaction between these variables described above, the second study focused on the variables collectively using a person-oriented approach, which aimed to classify distinct profiles of early adolescents based on correlates of PA. The outcome variables were also broadened to include active transport and overall PA across two time points. Findings from this second study illustrate that the highly supported, shortest commuters produced the highest levels of self-reported PA and that affluent, short commuters were the most likely to use active transport to travel to school. The affluent, short commuters lived a relatively short distance to school in areas of the lowest deprivation and had relative moderate family support of PA. The highly supported, shortest commuters were characterised by the highest family support of PA and lived the shortest distance to school in areas of low deprivation. Study 1 evidenced an association between biological maturation and PA behaviour; however, study 2 displayed that biological maturation did not meaningfully contribute to the class characteristics, and were not a predictor of PA. Previous evidence as to whether early, average or late maturing adolescents are more likely to disengage from PA is mixed and tends to focus on one gender only (Sherar, Cumming, Eisenmann, Baxter-Jones, & Malina 2010; Bacil, Mazzardo, Rech, Legnani, & Campos, 2015). Thus for the third study a more focused inspection of biological maturity was undertaken. Biological maturity status was investigated as a predictor of PA behaviour at two subsequent time points (6 9 months after baseline and 12 18 months after baseline) and whether there was variation across genders. Findings displayed that biological maturity status does not predict subsequent PA, with no distinction across genders. To conclude, the final study examined additional forms of PA behaviour. For children to develop and maintain healthy PA behaviours, their PA during the school day, particularly during physical education (P.E) classes is important (Owen, Smith, Lubans, Ng, & Lonsdale, 2014). Self-reported PA was divided into school-time PA (during P.E. lessons, break and lunchtimes) and leisure-time PA (after school, during evenings and weekends). The final study fully utilised the longitudinal data collected and utilised longitudinal growth modelling to describe the changes in PA behaviour across 12-18 months during early adolescence. Results displayed that school-time PA and leisure-time PA are distinct. Males; those from less deprived backgrounds and individuals with higher family support of PA all separately reported more school-time PA than their counterparts (females, those from higher deprived backgrounds and individuals with lower family support of PA) at baseline. Males and those with higher family support of PA also reported more leisure-time PA than their respective counterparts at baseline. On average, both genders decreased in school-time PA across 18 months yet for leisure-time PA, on average, there was no change over time and no significant difference in the rate of change between genders. There were no observed significant differences in the rate of change between multiple deprivation status and biological maturation across the 18 months for both behaviours. For family support, on average school-time PA decreased over time and results showed significant difference in the rate of change between individuals with lower or higher levels of family support of PA across the 18 months. On average, there was no change over time for leisure-time PA yet there was a significant difference in the rate of change between individuals and their family support of PA across 18 months. Further analysis demonstrated if an individual s family support increases, so does their leisure-time PA and vice versa. These overall key findings demonstrate the complexity of PA behaviour throughout early adolescence. This thesis works towards predicting individuals, correlates and determinants that may be susceptible to physical inactivity and/or a decrease in activity over time. Results can be used to target and direct PA intervention work.
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Molnar, Matthias [Verfasser], and Rainer [Akademischer Betreuer] Deutzmann. "Molekulare Funktion und Transport von MIA (Melanoma Inhibitory Activity) / Matthias Molnar ; Betreuer: Rainer Deutzmann." Regensburg : Universitätsbibliothek Regensburg, 2016. http://d-nb.info/112995644X/34.
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34
Yolcubal, Irfan. "In-situ monitoring of microbial activity and biodegradation during solute transport in porous media." Diss., The University of Arizona, 2001. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2001_290_sip1_w.pdf&type=application/pdf.
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Capestrano, Mariagrazia. "Molecular mechanisms involved in protein-transport-related membrane remodelling triggered by PLA2 enzyme activity." Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528250.
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36
梁凱倫 and Hoi-lun Helen Leung. "The application of activity-based transport demand modeling in Hong Kong: a feasibility study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41549193.
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Leung, Hoi-lun Helen. "The application of activity-based transport demand modeling in Hong Kong a feasibility study /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41549193.
Повний текст джерела
38
Adams, Emma J. "Understanding and promoting walking for transport in adults." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/33850.
Повний текст джерелаАнотація:
BACKGROUND. The benefits of physical activity for physical and mental health and well-being are well evidenced. Despite this, a substantial proportion of the adult population in England do not meet current recommended guidelines for physical activity leading to a significant burden on individuals, health services and the economy. Strategies are needed which lead to sustainable increases in physical activity at the population level. Walking is a free and accessible behaviour which is acceptable to most people and can be incorporated into everyday activities. Walking for transport is a type of walking which is undertaken specifically to travel from one point to another to reach a destination. Gaining an understanding of behavioural and contextual influences on walking for transport is important to facilitate specificity in designing effective interventions. Evaluating both the implementation and effectiveness of interventions to promote walking for transport in real-world settings may help to improve interventions and determine how they can be implemented at scale to impact population levels of physical activity. The research in this thesis aimed to contribute to the evidence base relating to understanding the factors influencing and the promotion of walking for transport in adults to address the problem of how to increase population levels of physical activity to improve health and well-being. Eight research articles are presented which used data collected as part of three research projects: Impact of Constructing Non-motorised Networks and Evaluating Changes in Travel (iConnect), Walking Works and Fitter for Walking. RESULTS. The Transport and Physical Activity Questionnaire (TPAQ) was developed and its measurement properties for assessing different domains of physical activity were tested. It was found to be suitable for use in comprehensively assessing transport and physical activity behaviour with comparable reliability and validity to other similar measures. A new 13-item scale was developed to assess adults perceptions of the environment in the neighbourhood (PENS) in the UK context. This was found to have comparable reliability to other similar scales. Using PENS and TPAQ, walking for transport was found to be positively associated with perceptions of supportive infrastructure, availability of local amenities, and general environment quality in the residential neighbourhood. Walking to and from work was found to be positively associated with the perceived presence of convenient walking routes, suitable pavements, maintained pavements or convenient public transport in the workplace neighbourhood. Walking to and from work was also positively associated with employees who were aged < 30 years, did not have a car, had no free car parking at work, were confident of including some walking or intended to walk to or from work on a regular basis, and had support from colleagues for walking. It was negatively associated with employees perceptions that they lived too far away from work to walk, walking was less convenient than using a car for commuting, they did not have time to walk, they needed a car for work, or they had always travelled the same way. In a community-based intervention to promote walking for transport, a wide variety of small-scale environmental changes were made which were led by local authorities (e.g. removal of encroaching vegetation, new/improved pedestrian signage, new dropped kerbs/kerb improvements, and new, repaired or improved footpaths) or by communities (e.g. planting bulbs, shrubs or bedding plants, clean-up days and litter pick-ups). Additional activities were undertaken to help increase awareness of the benefits of walking and promote the newly improved routes (e.g. led walks, themed walks, development of maps/resources and community events). After 12 months, there was a decrease in pedestrian route use overall and in four out of the five case studies where data collection took place. However, after 14-20 months there was an increase in pedestrian route use overall and in all case studies. Participants in the intervention perceived the main impacts to be improved physical and social environments. Implementing the intervention was found to be complex and required considerable resource and time. Processes required for implementation of the intervention were identified which included planning, preparation and delivery phases. Adaptability of the intervention to fit the local context was highlighted as being critical for successful programme delivery. In a whole-workplace walking to work intervention, no changes in walking behaviour were observed which may have resulted from barriers in using volunteer employee walking champions to deliver activities, the programme components not being delivered as originally intended, the types of activities which were delivered, and lack of awareness and participation by employees. CONCLUSIONS. A range of factors operating at different levels which influence walking for transport behaviour in adults were identified, confirming the need for specificity in studying both the behaviour and the contexts in which the behaviour is undertaken. Evidence is provided of the barriers and facilitators for implementing community-based and workplace interventions which aim to promote the behaviour. These should be addressed to maximise the effectiveness of interventions. Researchers, practitioners and policy-makers should take these research findings into consideration in the future design, planning and implementation of co-produced, multi-level interventions which aim to promote walking for transport. Future research should identify causal factors influencing walking for transport, improve intervention content and optimise intervention implementation. Researchers should address methodological limitations of work in this area, including the application of more rigorous study designs and the use of more reliable and valid measures of walking for transport and overall physical activity. Together this will maximise the potential impact of walking for transport interventions for promoting physical activity and improving health and well-being at the population level.
39
Avila-Palencia, Ione 1985. "Urban environment, transport behaviours, and health." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/665298.
Повний текст джерелаАнотація:
Urban environments are very complex systems with a myriad of factors intricately related. Built environment, transport, physical activity and sedentary behaviours, air pollution, and social contacts and feelings of loneliness can have effects on urban population’s health and well-being. Also, some of these determinants can be associated and can interact between them modifying their effects on health. According to the World Health Organisation (WHO), health is “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. Taking into account this comprehensive health definition, this thesis covered different layers of health: general, mental, and physical. With four different studies, the results of the present thesis suggest that it is possible to design urban environments that can increase physical activity levels, mainly through active transport, and that the crime-safety perceptions can have an important role in terms of reinforcing the effects of the built environment on physical activity and sedentary behaviours. Furthermore, active transport, mainly bicycle use, seems to be a source of good mental health and well-being, and a tool to boost social capital production. Increasing physical activity levels also seems to be a good way to improve cardiovascular health through blood pressure levels reduction.
The present thesis suggests that urban and transport planning have a great potential to promote healthy behaviours and ensure mental and physical health of city dwellers, mainly through active transport promotion. In order to improve the health promotion through urban environment, more research about aesthetics urban attributes, urban social capital production, effects on mental health and well-being, and effectiveness of urban interventions is needed.Los entornos urbanos son sistemas muy complejos con una miríada de factores intrincadamente relacionados. El entorno construido, el transporte, la actividad física y los comportamientos sedentarios, la contaminación del aire y los contactos sociales y los sentimientos de soledad pueden tener efectos en la salud y el bienestar de la población urbana. Además, algunos de estos determinantes se pueden asociar y pueden interactuar entre ellos modificando sus efectos sobre la salud. Según la Organización Mundial de la Salud (OMS), la salud es "un estado de completo bienestar físico, mental y social y no simplemente la ausencia de enfermedades o dolencias". Teniendo en cuenta esta definición integral de salud, esta tesis cubre diferentes niveles de salud: general, mental y física. Con cuatro estudios diferentes, los resultados de la presente tesis sugieren que es posible diseñar entornos urbanos que puedan aumentar los niveles de actividad física, principalmente a través del transporte activo, y que las percepciones de seguridad con respecto al crimen pueden tener un papel importante en términos de reforzar los efectos del entorno construido sobre la actividad física y los comportamientos sedentarios. Además, el transporte activo, principalmente el uso de bicicletas, parece ser una fuente de buena salud mental y bienestar, y una herramienta para impulsar la producción de capital social. El aumento de los niveles de actividad física también parece ser una buena forma de mejorar la salud cardiovascular a través de la reducción de los niveles de presión arterial. La presente tesis sugiere que la planificación urbana y de transporte tienen un gran potencial para promover comportamientos saludables y garantizar la salud mental y física de los habitantes de las ciudades, principalmente a través de la promoción del transporte activo. Para ir mejorando la promoción de la salud a través del entorno urbano, se necesita más investigación sobre los atributos urbanos estéticos, la producción de capital social urbano, los efectos sobre la salud mental y el bienestar, y la efectividad de las intervenciones urbanas
40
Donovan, Edward Robert. "Lactate transport and metabolism: An integrative study of the energetics of brief activity in lizards." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p3190394.
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41
Yu, Xin 1964. "Metabolic flux, transport activity, and subcellular communication in intact hearts from dynamic ¹³C NMR spectroscopy." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/38855.
Повний текст джерелаАнотація:
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998.Includes bibliographical references (leaves 98-109).
The control of oxidative metabolism was studied using carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy to determine the ratelimiting steps in 13C labeling of glutamate. 13C NMR spectra were acquired from isolated rabbit hearts perfused with either 2.5 mM [2- 13C] acetate or 2.5 mM [2- 13C] butyrate, and with or without KCl arrest. The tricarboxylic acid (TCA) cycle flux and the interconversion rate between (-ketoglutarate and glutamate were determined by least-square fitting of a kinetic model to NMR data. Rates were compared to flux through glutamate-oxaloacetate transaminase (GOT). Despite similar oxygen use, hearts oxidizing butyrate showed delayed incorporation of 13C label into glutamate and lower TCA cycle flux due to the influence of [beta]-oxidation: 8.0±0.2 [mu]moles/min/g dry weight with butyrate versus 10.5±0.4 with acetate at normal workload; 1.7±0.1 with butyrate versus 2.9±0.1 with acetate at potassium arrest (mean±SD). The interconversion rate between ca-ketoglutarate and glutamate ranged from 4.1±0.9 (butyrate+KC1) to 10.7±1.0 gmoles/min/g dry weight (acetate), at least 20-fold slower than the flux through GOT, and this proved to be the ratelimiting step in glutamate labeling. The results indicate that dynamic 13C NMR is sensitive not only to TCA cycle flux but also to metabolite transport rate across the mithochondrial membrane. To explore the effect of altered transport rates on the kinetics of glutamate labeling, metabolite exchange across the mitochondrial membrane was observed with 13C NMR spectroscopy in hearts oxidizing 2.5 mM [2- 13 C] butyrate at normal (no lactate) or high cytosolic redox state (2.5 mM lactate). High cytosolic redox state showed little effect on substrate utilization and TCA cycle activity. The TCA cycle flux was 9.7±0.5 [mu]moles/min/g dry weight with butyrate only and 10.2±0.3 with butyrate plus lactate. However, lactate induced a more than four-fold increase in the interconversion rate, from 3.1±0.2 gmoles/min/g dry weight to 14.3±2.0. These data indicate increased metabolite transport across the mitochondrial membrane due to stimulated malate-aspartate shuttle activity in response to elevated cytosolic redox state.
by Xin Yu.
Sc.D.
42
Brett, Kendra Elizabeth. "Maternal Phenotype, Directly Measured Physical Activity and Associations with Placenta Nutrient Transport Related Gene Expression." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32514.
Повний текст джерелаАнотація:
The intrauterine environment plays an important role in fetal development and downstream health. Given the rise in maternal obesity and the incidence of babies being born large-for-gestational-age, research is needed exploring the mechanisms through which maternal obesity and health behaviours affect the delivery of nutrients to the fetus. This thesis includes three manuscripts in the pursuit of two objectives: 1) To determine whether there are changes in placenta nutrient transport-related gene expression in response to obesity, excess gestational weight gain, and variations physical activity and diet, and 2) To examine whether the Pregnancy Physical Activity Questionnaire is a reliable estimate of physical activity during the second trimester of pregnancy. In manuscript 1, we found that maternal obesity was not related to placenta nutrient transport-related gene expression, with the exception of lower placental mTOR expression in obese women who delivered male offspring, however, gestational weight gain was related to the gene expression of key proteins in the placenta. In manuscript 2, it was determined that the Pregnancy Physical Activity Questionnaire significantly overestimates physical activity and is not correlated with direct measures of activity and thus should not be used in future research. In manuscript 3, we found that physical activity and diet modify the expression of the genes involved in placenta nutrient transport. Meeting physical activity guidelines was associated with lower expression of a fatty acid transporter and higher expression of an amino acid transporter, while sugar intake was related to the expression of a glucose transporter. Together, the studies that make up this thesis suggest that there are numerous factors that may be contributing to placenta nutrient transport-related gene expression in humans and that future research on the placenta ought to include direct measures of physical activity and maternal diet, as well as account for gestational weight gain with respect to the guidelines and fetal sex.
43
Villafuerte, Francisco C. "Carbonic anhydrase activity and its role in membrane H+-equivalent transport in mammalian ventricular myocytes." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:f355ea40-a6a8-45ed-bc78-408bec2c16d2.
Повний текст джерелаАнотація:
Carbonic anhydrases (CAs) are fundamental and ubiquitous enzymes that catalyse the reversible hydration of CO2 to form HCO3- and H+ ions. Evidence derived from heterologous expression systems has led to the proposal of a novel role for CA in intracellular pH regulation, where its physical and functional coupling to membrane H+ -equivalent transport proteins appears to enhance their activity. It has yet to be established whether such a functional association occurs naturally in wild-type cells. Additional evidence on CA activity in-vitro, has also suggested that certain CA isoforms are regulated by physiological changes of pH, an effect that may then affect their ability to enhance H+ -equivalent transport. No information, however, exists on the pH sensitivity of CA in intact cells. Finally, pharmacological inhibition of CA activity has been reported previously for various compounds, in addition to those designed specifically as CA inhibitors. It is possible that some compounds, currently used to inhibit membrane H+ transport, may also target CA. The present work has examined functional aspects of CA activity in ventricular myocytes isolated enzymically from rat heart, focusing on the potential role of C A in controlling sarcolemmal Na+/H+ exchange (NHE) and sarcolemmal Na+-HCO3- cotransport (NEC). NHE and NEC activity were estimated from the rate of recovery of intracellular pH (pHi), following an intracellular acid load in myocytes loaded with carboxy-SNARF-1 (a pH-sensitive fluorescent dye, used to measure pHi)). In other experiments, in-vitro CA activity was assessed from the time-course of pH change after addition of CO2-saturated water to a buffered solution containing either CA II or a cardiac homogenate. In further experiments, intracellular CA activity was assessed from the rate of CO2-induced fall of pHi. Three major results emerged, (i) In intact myocytes, CA activity doubles acid extrusion on sarcolemmal NBC, but has no effect on NHE activity. Facilitation of NBC activity by CA is likely to be mediated by an intracellular CA isoform. (ii) In-vitro and intracellular CA activity displays strong pH-dependence within the physiological pH range, activity declining with a fall of pH. (iii) The NHE inhibitor, cariporide, the bicarbonate transport inhibitors DIDS (4,4'- diisothiocyanatostilbene-2,2'-disulphonic acid) and S0859 (an experimental compound from Sanofi-Aventis), and the aquaporin blocker, pCMBS (p-chloromercuribenzene sulphonate), all showed strong inhibitory activity towards CA in-vitro, but had no effect on intracellular CA activity. Overall, the work provides the first clear demonstration of a functional role of CA activity in H+-equivalent transport in a wild-type cell. CA thus represents an important regulatory mechanism of H+ -equivalent transport. The pH sensitivity displayed by in-vitro and intracellular CA activity may also have significant functional consequences for pHi regulation. CA inhibition by various membrane transport inhibitors highlights the need for careful drug and experimental design, to avoid secondary inhibition of CA activity and its side-effects. The present work thus provides insight into the functional roles of CA, plus important new information on the enzyme's pharmacological properties.
44
Walker, Glen William, and not available. "Electron Transfer Reactivity, Synthesis, Surface Chemistry and Liquid-Membrane Transport of Sarcophagine-Type Poly-Aza Cage Complexes." The Australian National University, 1997. http://thesis.anu.edu.au./public/adt-ANU20010702.124104.
Повний текст джерелаАнотація:
[Formulae and special characters can only be approximated here. Please see the pdf version of the Abstract for an accurate reproduction.]
The kinetics for outer-sphere electron transfer between a series of cobalt(II) poly-aza
cage ligand complexes and the iron(III) sarcophagine-type hexa-aza cage complex,
[Fe(sar)]3+ (sar = 3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane), in aqueous solution
have been investigated and the Marcus correlation is used to deduce the electron self-exchange rate constant for the [Fe(sar)]3+/2+ couple from these cross-reactions. The
deduced electron self-exchange rate constant is in relatively good agreement with the
experimentally determined rate constant (k ex calc = 4 ´ 10 5 M -1 s -1 ; k ex obs = 8 ´ 10 5 M -1
s -1 ). The successful application of the Marcus correlation to the electron transfer
reactions of the Fe cage complex is consistent with the trend for the Co, Mn, Ni and Ru
cage complexes which all follow the pattern of outer-sphere electron transfer reactivity
expected from the Marcus-Hush formalism. A comparison of predictions based on the
Marcus correlation with the experimentally determined kinetics of an extended series of
cross reactions involving cobalt cage complexes with low-spin-high-spin cobalt(III)/(II)
couples shows that electron transfer reactions involving large spin changes at the metal
centre are not necessarily anomalous in the context of the adiabatic Marcus-Hush
formalism. The results of this study also show that for suitable systems, the Marcus
correlation can be used to reliably calculate the rates of outer-sphere electron transfer
cross-reactions, with reaction free-energy changes spanning the range -6 to -41 kJ mol -1
and many different combinations of initial electronic configurations. Together, these
results provide a coherent and internally consistent set of experimental data in support
of the Marcus-Hush formalism for outer-sphere electron transfer. The results with the
caged metal-ion systems also highlight the special nature of the mechanism of electron
transfer in reactions of metal-aqua ions.
¶
A new range of symmetrically disubstituted hexa-aza sarcophagine-type cage
ligand complexes are prepared in this study by the base-catalysed co-condensation of
formaldehyde and a-methylene aliphatic aldehydes with cobalt(III) tris(1,2-diamine)
precursors in acetonitrile solution. Encapsulation reactions based on the condensation
of the weak carbon di-acids propanal and decanal with formaldehyde and the cobalt(III)
tris(1,2-diamine) precursors, [Co(en)3 ] 3+ (en = 1,2-ethanediamine) and D-lel3 -[Co((R,
R)-chxn)3 ] 3+ (chxn = 1,2-cyclohexanediamine), yield unsaturated cobalt(III) cage
complexes with an endo-cyclic imine function in each cap. The Co III -coordinated endo-cyclic imine units of the cage ligands are reactive electrophiles that are readily reduced
by the BH4 - ion to give the corresponding symmetrically di-substituted hexaamine
macrobicyclic cage ligands. The nitromethane carbanion is also shown to add at the
endo-cyclic imine function to yield a novel nitromethylated cage ligand complex. The
latter reaction introduces a new method for the regioselective functionalisation of cage
ligands at sites removed from the more commonly substituted bridgehead positions.
The capping of cobalt(III) tris(1,2-diamine)-type complexes with weak CH-acids
developed in this study introduces a new and more direct route to symmetrically di-substituted cage ligand complexes.
¶
A new range of cobalt(III) surfactant cage complexes, with linear octyl, dodecyl
and hexadecyl hydrocarbon chains built directly into the bridgehead structure of the
cage ligand, have been prepared by the base catalysed co-condensation of formaldehyde
and long chain aliphatic aldehydes with the tripodal cobalt(III) hexaamine complex,
[Co(sen)]3+ (sen = 4,4',4''-ethylidynetris(3-azabutan-1-amine)), in acetonitrile solution.
Chiral surfactant cage complexes are obtained by capping reactions beginning with the
optically pure L-[Co(sen)]3+ precursor complex. The cobalt(III) cage complexes with
octyl to hexadecyl substituents are surface active and reduce the surface tension of
water to levels approaching those of organic solvents. The dodecyl substituted cage
complex forms micelles in aqueous solution when the concentration of cage complex is
> 1 ´ 10 -3 mol dm -3 at 25 °C. The cobalt(III) cage head-group of these surfactants
undergoes an electrochemically reversible one-electron reduction to the corresponding
cobalt(II) cage complex. The reduction potential of the surfactant head group can be
tuned to more positive potentials by replacing the bridgehead hydrocarbon chain
substituent with an ether linked hydrocarbon chain. The cobalt(III) surfactant-cage
complexes are biologically active and are lethal to the tapeworm Hymenolepis diminuta,
and the vaginal parasites, Trichomonas vaginalis and Tritrichomonas foetus. The
surfactant cage complexes also cause lysis in red-blood cell membranes at
concentrations as low 10 -5 mol dm -3 . Their biological activity is linked to the high
head-group charge (3+) and size which cause distortions in biological membranes when
the membrane is treated with these molecules. The combination of the chemically
reversible outer-sphere redox properties of the cobalt cage head-groups and the chirality
of the head group introduces a new and possibly unique series of chiral surfactant
coordination complexes which are also redox active.
¶
The chiral carboxylic-acid ionophore, lasalocid A, has been used to promote the
selective supramolecular transport and extraction of cobalt(III) hexa-aza cage cations
and related tripodal cobalt(III) complexes. The conjugate base anion of lasalocid A
forms stoichiometric outer-sphere complexes with the cobalt(III) cage and tripod
complexes. These outer-sphere complexes are highly lipophilic and partition strongly
from water into a chloroform phase. The extraction of the dissymmetric cobalt(III)
complexes by the chiral polyether anion is enantioselective for many systems and
results in the partial resolution of initially racemic complexes in the aqueous phase. A
strong structural preference was demonstrated by the ionophore for symmetrically
disubstituted cobalt(III) hexa-aza cage cations with a D-absolute configuration of the
ligand about the metal-ion and an R configuration of the coordinated secondary amine
N-H groups. The lasalocid A anion was also shown to promote the transport of the
complexes, intact, across a chloroform bulk-liquid membrane against an NH4 +
concentration gradient. The transport of the cobalt(III) complexes was also
enantioselective and resulted in partial resolution of the initially racemic aqueous phase.
The most efficiently transported enantiomer of each complex was also the most
efficiently extracted isomer in all systems examined, consistent with a transport process
limited by interfacial diffusion. The magnitude of the enantiomer separation obtained in
some systems was sufficient to indicate that lasalocid A mediated extraction and
transport may become a practical method for the resolution of particular types of
kinetically-inert chiral metal-amine complexes.
45
Bai, Jing. "Dopamine transporter (DAT) activity regulates the induction of synaptic plasticity in rodent prefontal cortex." Paris 6, 2011. http://www.theses.fr/2011PA066210.
Повний текст джерелаАнотація:
Le transporteur de la dopamine (DAT) est la principale cible des psychostimulants. Dans cette thèse, par l’utilisation d’outils génétiques et pharmacologiques chez le rongeur, nous avons étudié le rôle de DAT sur l’induction de la plasticité synaptique dans le cortex préfrontal (CPF). 1) sur des coupes de PFC chez le rat, nous pouvions induire une dépression à long terme (DLT) dopamine (DA) dépendante. Cette DLT requérait les activations de PLC, PKC et ERK1/2 et était bloquée par un inhibiteur spécifique de DAT: GBR12909. L’augmentation excessive de DA, due à l’inhibition de DAT, bloquait la DLT en agissant sur D1R. De plus la co-application du potentiateur allostérique du récepteur mGluR5 CDPPB annulait l’effet bloquant de GBR12909 et rétablissait ainsi la DLT. Ces induction et rétablissement de DLT étaient corrélés avec le niveau de phosphorylation de ERK1/2. 2) en utilisant des souris DAT-KO, un modèle génétique d’hyperdopaminergie, nous trouvions que la stimulation à haute fréquence (SHF) induisant une potentiation à court terme chez les souris sauvages mène à une potentiation à long terme (PLT) chez les souris DAT-KO. La PLT facilitée était dépendante de la suractivation des D1R durant la stimulation et abolie par CDPPB. La facilitation de la PLT était reproduite chez les souris sauvages par l’application de GBR12909 durant la SHF. Ces résultats indiquent que l’hyperdopaminergie causée par la dysfonction de DAT facilite la LTP et bloque la LTD dans le CPF du rongeur, ainsi DAT dans le CPF joue des rôles fonctionnels importants. Nous suggérons alors que l’anormalité de la plasticité synaptique causée par la dysfonction de DAT doit mener à des troubles cognitifs
46
Estmer, Nilsson Camilla. "Viral Control of SR Protein Activity." Doctoral thesis, Uppsala : Acta Universatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5124-1/.
Повний текст джерела
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Veizis, Ilir Elias. "Enhanced ERK1/2 activity a central feature of cystogenesis in ARPKD implications for ion transport phenotype /." Connect to text online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1102023062.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Case Western Reserve University, 2005.[School of Medicine] Department of Physiology and Biophysics. Includes bibliographical references. Available online via OhioLINK's ETD Center.
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Su, Jing S. M. Massachusetts Institute of Technology. "Reclaiming residual space from elevated transport infrastructure : time, space, and activity under the Chicago Brown Line." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33744.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2005.Includes bibliographical references (p. 95).
This thesis studies the non-transport functions of the residual space generated by elevated transport infrastructure and its relationship with abutting neighborhoods The space under the Chicago Brown Line, among all other elevated train lines, is often considered as an undesirable and useless urban eyesore. As part of the transit authority's right of way, such space is usually labeled "mass transportation corridor" on planner's land use maps. However, more careful observations reveal that a considerable portion of the land underneath the train tracks has been actively used by the adjacent residents or business owners for a variety of purposes other than providing transit service. These observations place an interesting question mark on the stubborn negative common perception of the residual space associated with the elevated train lines and other large scale transport infrastructure: why the fact that such residual space is actually being used cannot change the notion that it is not usable? By categorizing the observed activities under the Brown Line into private, quasi-public, and public use types, it is clear that most of the spontaneous reclamation actions are intended for private activities.
(cont.) This in a sense indicates that private activities have limited contribution to the entire image of the social character of the residual space. Analysis of the physical characteristics of the residual space shows that although the physical condition of a given plot of residual space does not determine the occurrence of activities on it, the quality of the physical environment is an important factor of the quality of the social activity. Therefore, this thesis argues that one effective way to reclaim the residual spaces both physically and psychologically is to showcase a series of key projects that transform them into delightful places well-programmed for public/quasi-public activities. Following this argument, the main body of the thesis explores strategies of reclaiming the residual space by presenting cases of similar practice in other places and proposing implementation prototypes designed for the Brown Line. The lessons learned from the case studies and the design exercises are conceptualized into guidelines that cover a broad range of considerations from engaging participants, programming activities to spatial design and temporal planning.
(cont.) In all, this thesis attempts to provide alternative view points for the transit authority to upgrade, manage, and maintain its right of way, to urge city planners to look into flexible and overlapped land use patterns, and to express my strong belief in good urban environment.
by Jing Su.
S.M.
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Hutchinson, Kelly Ann. "Assessing the Effect of Exercise During Pregnancy on Myokine Response and Placental Growth and Function In Vitro." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39808.
Повний текст джерелаАнотація:
Background: It is well established throughout the literature that regularly engaging in physical activity throughout pregnancy is associated with optimized health outcomes for both the mother and the fetus. The mediators and mechanistic pathways through which these observed exercise-induced outcomes are achieved are largely unknown. This thesis attempts to address this gap in knowledge.
Methods: The objective of the first study was to develop an exercise protocol based on the recommendations from the ‘2019 Canadian guideline for physical activity throughout pregnancy’ and to subsequently evaluate the myokine response post-exercise. Pregnant (n=13) and non-pregnant (n=17) women performed a moderate-intensity bout of treadmill walking following which pre- and post-exercise serum for a panel of ten well-characterized myokines was analyzed. The objective of the second study was to evaluate whether acute and/or chronic exercise elicited changes in metrics of placental growth and development – thereby proposing possible mechanisms through which physical activity may be conferring health benefits to the fetus. Serum (pre- and post-exercise) collected from the first study was used to treat placental cell lines to assess the effect of acute exercise on cellular proliferation as well as nutrient transporter (GLUT1, SNAT1, FATP4) expression and localization. Term placental tissue collected from active (n=10) and non-active (n=10) participants in the PLACENTA study were used to evaluate the role of chronic exercise on changes in nutrient transporter (GLUT1, SNAT1, FATP4) expression and localization.
Results: Pregnant women from the first study exhibited higher levels of four myokines post- versus pre-exercise: FGF21, EPO, BDNF and IL-15. As for the second study, BeWo cell lines treated with serum collected from pregnant women yielded higher GLUT1 expression compared to non-pregnant serum, independently of exercise. Lastly, FATP4 expression was found to be higher in term placentas of active compared to non-active pregnant women.
Conclusion: This thesis identified four myokines that are elevated in the serum of pregnant women following a bout of acute exercise. The role of these myokines in pregnancy remains to be elucidated. Further, chronic and acute exercise are shown to alter expression of key placental macronutrient transporters.
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Miller, Timothy J. "FXYD5 modulates Na,K-ATPase activity and is increased in cystic fibrosis airway epithelia." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1208379285.
Повний текст джерела