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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Structure Determination of Proteins of Unknown Origin by a Marathon MR Protocol and Investigations on Parameters Important for Molecular Replacement Structure Solution

Hatti, Kaushik S January 2016 (has links) (PDF)
Occasionally, crystallisation of proteins works in mysterious ways! One might obtain crystals of a protein of unknown identity in place of the protein for which crystallisation experiments were performed. If the investigator is not aware of such possibilities, valuable time and resources might be lost in attempting to determine the structure of such proteins. Instances of non-target protein getting crystallised may not come to light at all or may be realised only when attempts to determine the structure completely fail by conventional procedures after collecting and processing the diffraction data. Usually, it is not possible to reproduce the crystals of the same protein as their occurrence is serendipitous. Such rare instances of crystallisation are probably caused by fluctuating environmental or crystallisation conditions and are not reproducible. It could also be due to contaminating microbes, which is more likely when the experimentalist is not well experienced. Therefore, experimental phasing of the data collected on serendipitously obtained crystals could be a challenging task. With the rapid increase in the number of structures deposited in the protein data bank (PDB), molecular replacement has become the method of choice for structure determination in macromolecular X-ray crystallography. This is due to the fact that it is possible to select a suitable phasing model for most target proteins based on their sequence information. However, if the identity of the target protein itself is uncertain, all attempts of structure determination using phasing models selected on the basis of target protein sequence-dependent search would fail. Sequence-independent ab initio phasing techniques such as ARCIMBOLDO (Meindl et al., 2012), which has recently become available, could provide leads only if the non-target protein is an all-α-protein and the associated diffraction data extends to a resolution better than 2 Å. Even then, the success rate with this technique is low. Hence, it becomes important to employ a sequence-independent method of structure determination for such mysteriously obtained crystals. This thesis reports crystal structures of proteins which are serendipitously crystallised using a large-scale application of Molecular Replacement (MR) technique (referred in this thesis as MarathonMR). This thesis also presents an evaluation of molecular replacement strategies for structure determination. The thesis begins with an overview of crystallographic methods of structure determination with an emphasis on the method of molecular replacement (Chapter 1). The most prominent of the results obtained in the course of these investigations pertains to a crystal obtained during routine crystallisation of a viral protein mutant in the year 2011. The cell parameters were different from cell constants of crystals obtained with other known viral protein mutants crystallised earlier in the same laboratory. Unfortunately, this crystal could not be reproduced in the same form in subsequent crystallisation trials. All attempts to determine the structure through conventional molecular replacement techniques using a combination of domains from a nearly identical virus coat protein protomer as the phasing model had failed. The data was shelved as “not-solvable” in late 2011. However, the crystal had diffracted to 1.9 Å and had excellent merging statistics. Therefore, the data was retrieved recently and additional attempts were made to determine the structure through phasing techniques that have become available recently. Techniques such as AMPLE (Bibby et al., 2013) and Rosetta (DiMaio, 2013), which use large-scale homology models coupled with molecular replacement, did not lead to meaningful solutions. A couple of helices identified by ARCIMBOLDO (Meindl et al., 2012) were neither correct (retrospectively) nor sufficient to determine the entire structure. Given the excellent merging statistics of the crystal data, there was significant motivation to determine the structure, though it meant developing a fresh protocol. It was at this time that we came across the work of Stokes-Rees and Sliz (2010) in which they had demonstrated that it is possible to determine structure of proteins of unknown identity by employing almost every known protein structure as a potential phasing model. The work reported in the thesis is a result of an earlier project to examine the relationship between properties of phasing models and the quality of target protein model generated through MR by employing large scale molecular replacement runs. This project was initiated because of the realisation that the recent explosion in crystallographic structural studies has resulted in near complete exploration of the “fold-space” of proteins and PDB now has a representative structure for most plausible folds of proteins. Some folds are highly represented in the PDB. Hence, it is likely that there would be at least one homologue in the PDB which could be used as a phasing model to successfully determine the structure of a protein of unknown identity if the diffraction dataset is of excellent quality. Hence, the single dataset which had diffracted to 1.9 Å resolution was used to develop a MarathonMR procedure for structure determination. MarathonMR procedure takes sequence-independent approach to structure determination and employs large-scale molecular replacement calculations to identify the closest homologue (in structural terms initially). This protocol is described in Chapter 2 (Materials and methods) of the thesis. Through MarathonMR, structure of the dataset which had remained unsolved for 5 years was finally determined. Nearly complete sequence of the polypeptide could be deduced by inspecting the electron density map due to the high resolution and quality of the map. The protein was found to be a phosphate binding protein from a soil bacterium Stenotrophomonas maltophilia (SmPBP). The way in which the structure was determined and possible explanations for the mysterious source of this protein which had crystallised instead of the target protein is discussed in Chapter 3. Though MarathonMR procedure was developed to solve a single dataset, it was soon realised that the same procedure could be applied to other similar datasets, all of which had diffracted to reasonable resolutions with good merging statistics but had remained unsolved for unknown reasons. Among such datasets, one of the datasets which was collected in 2007 and had diffracted to 2.3 Å resolution had cell parameters very close to that of SmPBP. Hence, a poly-alanine model of the structure of SmPBP, which was determined by then, was used as the phasing model to run molecular replacement and the structure was readily solved. It was surprising to note that SmPBP had crystallised serendipitously not once but twice, once in 2011 resulting in crystals that diffracted to 1.9 Å resolution and earlier in 2007 in crystals that diffracted to 2.3 Å resolution independently by two different investigators in the same laboratory. Both the structures are nearly identical and a comparison of these structures is presented in Chapter 4. Structure of SmPBP determined at 2.3 Å resolution by MarathonMR also corresponds to the dataset that had remained unsolved for the longest period of time (9 years). This success of structure determination after the lapse of such a long period emphasises the importance of carefully preserving X-ray diffraction data irrespective of its immediate outcome. In Chapter 5 of the thesis, another instance of non-target protein crystallisation, the structure of which was determined using the MarathonMR procedure is described. The crystal was obtained while carrying out crystallisation of mutants of a survival protein (SurE) expressed in Salmonella typhimurium when the bacterium is subjected to environmental or internal stresses. The original investigator had used the structure of SurE as the phasing model to determine structure of the mutant crystals and obtained a model with R and Rfree of 35% and 40%, respectively. However, the model did not refine further to lower R-factors suggesting that the solution obtained may not be correct. MarathonMR indicated that the fold of the crystallised protein could be similar to that of glycerol dehydrogenase. As SurE shares some fold similarity with one of the domains of GlyDH, the original investigator might have been able to achieve a limited success with R/Rfree factors of 35% and 40%, respectively. As the merging statistics for this diffraction data set was poor, the diffraction images were reprocessed in XDS program on Xia2 automated spot processing pipeline. The data statistics indicated merohedral twinning (14%). However, using appropriate parameters, it was possible to refine the structure obtained by MarathonMR to acceptable R/Rfree using the Refmac program. Four protomers were present in the crystal asymmetric unit (ASU). Non-crytsallographic symmetry averaging of electron density over these four molecules further improved the electron density. As the data was limited to 2.7 Å resolution, it was not possible to deduce the identity of every residue of the protein unambiguously based solely on the resulting electron density map. With the identity of the amino acids that could be deduced with certainty, it was clear that the protein belongs to glycerol dehydrogenase from a species of Enterobacteriacea family. Though a similar structure of glycerol dehydrogenase has been reported from Serratia, there are clear differences in many unambiguously determined residues which suggest that the protein is not from Serriatia. The protein has been named EnteroGlyDH as the source of the protein is likely to be from a species of Enterobacteriacea family. The structure of the protein, its biochemical implications and possible reasons for the serendipitous crystallisation of a non-target are discussed. Chapter 6 discusses the structure determination of an inorganic pyrophosphatase and catalytic domain of Succinyl transferase, the crystals of which had diffracted to 2.3 Å and 3.1 Å, respectively, but had remained unsolved. Neither of the datasets corresponds to the intended target proteins. The dataset corresponding to the protein whose structure was determined as that of an inorganic pyrophosphatase was provided by a colleague from a different laboratory in the Indian Institute of Science. It is interesting to note that the investigator had carried this dataset to one of the CCP4 workshops and had tried to determine the structure with the help of experts in the workshop. The attempts to determine its structure had however failed for reasons that are obvious now. The original investigator was unfortunately making efforts with an erroneous assumption on the identity of the target protein. As these enzymes are well studied, their structures and functions are briefly discussed. It is already well established that molecular replacement is being used with increasing frequency as the phasing technique when compared to other experimental phasing techniques. With the ever growing number of structures in the PDB, high population of certain folds and a near-plateau attained in the identification and growth of new folds, it is reasonable to expect that molecular replacement will be used even more frequently in the years to come. Therefore, for carrying out molecular replacement for a given diffraction dataset of a target protein, it is very likely that several homologous structures would be available in the PDB that could be used as potential phasing models. Hence, it becomes important to understand the influence of phasing model on the quality and accuracy of model generated through MR to achieve the best structure solution. To understand this relationship between phasing model and model obtained by MR protocol, re-determination of already known structures deposited in the PDB starting with their respective structure factors and various phasing models was initiated. Structures belonging to TIM beta/alpha-barrel (SCOPe ID: c.1) and Lysozyme-like (SCOPe ID: d.2) folds were chosen as targets. The structure of each target was re-determined serially starting with poly-alanine models of all available unique homologues as phasing models. Due to the multi-dimensional nature of this study, the results obtained were represented in a graphical form with nodes and edges. Detailed methodology of the work carried out and the data representation model are discussed in the Chapter 2 (Materials and methods). It was found that after a certain sequence identity cut-off, sequence identity between phasing model and target seems to have little influence on the quality and accuracy of the model generated through MR. Instead, other qualities of the phasing model such as Rfree and RSCC influence the quality of MR models. These results are discussed in Chapter 7. Learning from the work reported in this thesis are discussed in concluding chapter. The possible logical and programmatic upgrades to MarathonMR protocol and future path in which the relationship between phasing models and models generated through MR can be studied are discussed in Chapter 8 (Conclusion and future prospects).
102

Exploring the uses of mental skills by competitive road running athletes

Ngobese, Khayelihle Mbongeleni Emmanuel January 2015 (has links)
Research on athletes has shown that mental skills are an important component of being a successful athlete. The importance of these mental skills is seen in the number of athletes who have formally started training using mental skills training programmes (MST) according to the literature. The study of mental skills in South Africa lags behind other countries like USA, UK and Sweden. This particular study explored the use of mental skills by road running athletes. The study was conducted with six competitive marathon athletes. Semi-structured interviews were conducted as part of an elaborate qualitative methodology design. The data collected from these semi-structured interviews was analysed using thematic analysis. The results show that road running athletes use mental skills that include; mental rehearsal, planning, goal setting and self-talk. The athletes in this research showed the importance of mental skills and it is recommended that formal training in these mental skills will be highly beneficial not only to road running athletes but for all South African sports people in general
103

Motivace dobrovolníků a péče o ně v rámci běžeckých závodů RunCzech / Volunteer motivation and care in the RunCzech running events

Štenclová, Markéta January 2018 (has links)
Title: Volunteer motivation and care in the RunCzech running events Purpose: The main aim of this master's thesis is to find the motives contributing to be a volunteer at the RunCzech running events which are organized by the Prague International Marathon. Another goal is to discover how the organizer takes care of their volunteers, and how the leadership and volunteer coordination really works. Method: For this research on volunteer motivation questionnaires were used in electronic Google forms. The link for this survey was sent via e-mail and shared via social networks. The other methods were structural and semi-structural interviews with two employees of PIM, who are responsible for their volunteers during the organisation of RunCzech running events. The results were analysed with graphs and tables in MS Excel. Results: Based on the results the survey suggests more than half of volunteers are motivated by more than one motive at once. The atmosphere during the events and new experiences are two of the most important motives for volunteers. The behaviour of volunteer leaders also has an important influence on volunteer's motivation. The interviews showed that PIM searches for volunteers primarily from high schools. They try to motivate volunteers with the possibility to choose a volunteer...
104

Visibility, conviviality and active listening : A case study of an exogenous project in Africa´s last colony

Sánchez-Valladares Barahona, Celia January 2021 (has links)
The occupation of Western Sahara is a question of a forgotten colonization with a very limited framework of international recognition, media acknowledgment and talks. To break the remaining silence and invisibility, human rights activists have developed different initiatives, shedding light on the current situation of Western Sahara. This study investigates the Sahara Marathon campaign, an international sport event that has been developed in the Western Sahara refugee camps of Smara, El Aaiún and Auserd for twenty consecutive years.  Framing the Sahara Marathon as a case study, this degree project aims at inquiring into the potential impact and long-term implications of the international sport campaign, seeking “if” and “how” it contributes towards a social change and an end to the enforced invisibility of “Africa's last colony”, (Güell, 2015). In particular, this qualitative study examines the participatory approach and community engagement promoted through the campaign as well as the awareness-raising and dialogical processes triggered as a result of the Sahara Marathon sport event. The study is grounded on 23 in-depth interviews that have contributed to the external reliability of the research, underlining the reflections shared by organizers of the Sahara Marathon, drivers, freelancers, runners and most importantly human rights activists from Western Sahara. Findings reveal that the Sahara Marathon campaign raises awareness about the current situation in Western Sahara, contributing to a transnational acknowledgment of the conflict. The study also shows that active listening and convivial experiences are promoted throughout the campaign, dismantling stereotypes among communities coming from abroad and Saharawi people living in the refugee camps. In terms of participation, it has been concluded that the campaign uses a participation by consultation approach, needing a new model to showcase the utility and effectiveness of the event as well as to ensure its sustainability in the future.
105

Détection de ruptures de signaux physiologiques en situation in vivo via la méthode FDpV : cas de la fréquence cardiaque et de l'activité électrodermale de marathoniens / Change point detection of physiological signals within in vivo settings via the FDpV method : case of the heart rate and the electrodermal activity of marathoners

Cheikh Khalfa, Nadia 25 September 2015 (has links)
Cette thèse a été réalisée dans un cadre pluridisciplinaire alliant protocole expérimental, instrumentation dans des conditions de mesures in vivo, détection de ruptures associées à des changements d'états physiologiques et identification et prétraitement d'artefacts de mesures chez des coureurs de marathons. Nous avons considéré l'analyse de la variabilité du rythme cardiaque (VRC) et l'analyse de l'activité électrodermale (AED) pendant une course et lors des phases qui la précèdent et la suivent. La détection de ruptures de moyenne et de tendance est effectuée par la méthode Filtered Derivative with p-Value (FDpV) tout au long de cette thèse. La méthode FDpV est basée sur une analyse dynamique faisant appel à un modèle stationnaire par morceaux. Elle a permis en particulier d'introduire un indice de régulation cardiaque pour les coureurs. Un suivi des changements des états d'éveil et de motivation à travers l'AED par la détection de ruptures de la tendance pendant la course d'un semi-marathonien est également proposée. Ceci a permis de définir des signatures de début et de fin de course. Une attention particulière a été apportée à la composante tonique de l'AED reflétant le niveau d'activation affectif. Nous avons comparé trois méthodes d'extraction du niveau tonique en tenant compte des artefacts potentiels présents. Ce travail concerne des études de cas; il peut être étendu à une cohorte et englober plus de paramètres physiologiques (VO2, EEG,...). Ainsi, une classification des états d'éveil et de motivation peut être envisagée et représente des éléments significatifs de caractérisation des données physiologiques in vivo pour l'optimisation des performances sportives. / This thesis was carried out in a multidisciplinary approach that combines experimental protocol, instrumentation, in vivo measurements, physiological change detection instants and identification and preprocessing of measurement artefacts for marathon runners. We considered the analysis of the heart rate variability (HRV) and the electrodermal activity (EDA) recorded during a semi-marathon including pre and post competition periods. A study of the HRV and EDA change detection was carried based on the mean and the trend using the Filtered Derivative with pValue method (FDpV) throughout this thesis. This segmentation method is based on a dynamical approach using a piece-wise stationary model. As a result, itallowed to introduce an index of cardiac regulation for semi-marathon runners. Physiological state changes tracking of affective dimension i.e. "stress" and motivation via the EDA by change detection on its tonic component which reflects the EDA general trend throughout a semi-marathon was also proposed. This enabled us to characterize start and finish phases of a race which are key elements in any competition. A special attention was given to the tonic component of the EDA reflecting the overall level of affective activation. We compared three methods of tonic level extraction by taking into account the present potential artefacts. Thiswork focused on case studies; It can be generalized over a cohort and include more physiological parameters such that VO2 or EEG. Hence, a classification of stress states may also be considered and represent other significant features for characterizing in vivo physiological data for sport performance optimization.
106

智慧型跑者商業企劃書 / A BUSINESS PLAN FOR SMART RUNNERS

車培凱, Karmegam, Prakash Unknown Date (has links)
In the modern world, marathon running is taking over the fitness world and studies show that regular running will make people healthier, happier and fit. In India the yearly growth rate of marathon event is more than 150%. As more people gets boarded, the whole running industry is seeing boom and demand arises in all the services associated with these events. The evolution of technology and social media makes all the products and services migrate towards digital platform. Services associated with marathon events include race event management, getting connected with runners and clubs, reliable guidance and training techniques for preparing to run 42+ km, expert feedback on running gadgets like GSM watches, shoes, apparels etc. In current market, all these services served through different channels like runners club, Facebook, health magazines, websites for events and many more. Effective way to serve this group is to come up with “SMART Runners” which is exclusive for runners and serve all the needs associated with running events in single platform. This digital platform will use the crowd sourcing concepts to create contents that fits the Indian market needs with reliable information. For the event organizers, this platform will also act as a cloud service through which they can reach the runners, communicate and manage their race events effectively. As an investor, the proposal for creating a basic SMART Runners portal has positive NPV of INR 3,940,623 with CAGR of 20%. Though it may not be highly attractive however in short span it will become the leading “Running Portal” in India with approximately two million subscriptions. In the future this customer base can help the company to expand into various running related services and has bright prospects.
107

The role of strategic communication in sport events : The challenges of the PR RACE in attracting amateur athletes to distance running events in Romania / Rolul comunicării strategice în evenimentele sportive : Provocările PR RACE în atragerea atleților amatori la evenimentele de alergare pe distanțe lungi în România

Vavilov, Elena - Maria January 2018 (has links)
This year will be the 110th since the first time that athletes ran the exact distance of 42.195 km at the Olympic Games in London, the length known today as the standard distance for a marathon. Since then, the world of distance competitions has gone through remarkable transformations in structure, vision, strategy and location. Attending distance running events is a social global phenomenon, and thousands became hundreds of thousands in terms of participation rate. Starting 1980 the sport communication research experienced an exponential growth due to fast technological changes in sport events organization and promotion channels. The aim of this current research is to study the role of strategic communication in attracting amateur runners to engage in distance races, and the concept of Intelligence-led PR and its functionality during the challenges faced by PR practitioners. The concept is part of strategic communication theory and it has a key role in the communication process due to the significant social and economic impact of these events on the participants’ life and on the local markets. The study will focus on the content and data analysis of two distance running competitions organized in 2016 in Romania. The data collection was made by conducting two interviews with the representatives of the biggest sport event organizers in Romania - Bucharest RUNNING Club Association and Media Production Group, and examining several market reports. The main conclusions of this Master thesis are that research and planning, as well as using modern communication tools and new technologies, as part of strategic communication, have helped the big sport event organizers to reach targeted audiences, form and shape public’s perception about recreational activities and engage people to participate in running competitions. Another finding is that PR Intelligence, as a concept of strategic communication, is represented by a set of knowledge that can be gained both by education and relevant practice and makes this type of communication essential for an organization becoming one of the essential managerial functions. / <p>I would like to show my gratitude for the support I received from Bucharest RUNNING Club Association and Media Production Group Romania in conducting this study. Likewise, I express my hope that this research will be a useful input to the current literature in the sport communication area and strategic communication and it will be considered as inspiration for further research, and at the same time it will bring additional knowledge to other PR practitioners.</p>
108

China Run

Grant, Michael E. (Michael Edward) 12 1900 (has links)
China Run is a 92 1/2 minute documentary film which portrays an ultramarathon runner's record-setting 2,125 mile run across China in 53 days, starting at the Great Wall north of Beijing and concluding in Guangjhou (Canton). It is a story of the difficulties, both physical and emotional, suffered by the runner, as well as the story of his encounters with the people of China.
109

Education for Citizenship: A Study of the Effects of Cocurricular Student Philanthropy Education on Prosocial Behavior

Alonso, Félix José 25 October 2022 (has links)
No description available.
110

The Language of Sport: Understanding Chile and chilenidad through Marathon Races and Fútbol Games

Drafts-Johnson, Lilah, 12 December 2018 (has links)
No description available.

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