• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 11
  • 4
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 62
  • 62
  • 13
  • 12
  • 9
  • 8
  • 8
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 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.
31

Size-structured competition and predation in red-eyed treefrog tadpoles

Asquith, Christopher 25 March 2010 (has links)
Body size is important in determining the outcome of competition and predator-prey interactions. Size structure of a population (i.e. relative proportion of large and small conspecifics) may be particularly important in organisms with prolonged breeding periods and rapid growth where populations may have multiple cohorts at different stages of development competing for one resource. Both the consumptive and nonconsumptive effects of predators can also be size-dependent and can alter competitive interactions. Here we study the importance of size structure in the Neotropical leaf-breeding tree frog, Agalychnis callidryas. This species is a prolonged breeder such that multiple overlapping cohorts of differing sizes are common. Specifically, we examine size-specific intraspecific competition between A. callidryas tadpoles and then explore how predation affects these interactions. To determine the strength of inter-cohort competition, we manipulated the density and relative proportion of large and hatchling tadpoles in a response surface design and quantified growth. We then observed the effect of a dragonfly larvae predator (Anax amazili) on tadpole growth and survival at different size-structured treatments. Large tadpoles were greater per individual competitors while hatchlings were greater per gram competitors. When predators were added, dragonflies reduced survival and growth of hatchlings substantially, but had no effect on large tadpoles. Further, dragonflies reduced hatchling growth more when other hatchlings were present. The predator effect on hatchling growth was 23% larger than the effect of competition with large tadpoles, such that the importance of size structure for A. callidryas may be mediated more through predation than intercohort competition.
32

Modelo de difusão da inovação para instituto de pesquisa no Brasil / Innovation diffusion model for public research institute in Brazil

Ades, Cely 26 June 2013 (has links)
A proposta de criação de um modelo de difusão da inovação para institutos de pesquisa públicos no Brasil sugere que o inter-relacionamento de instituições de pesquisa e empresas pode ocorrer de maneira diferente da que vem sendo observada na prática. Os NITs são questionados como modelo único para gerir a política de inovação dos institutos de pesquisa para promover a transferência de tecnologia e interação com empresas. Com o objetivo de alavancar o desenvolvimento científico, por meio do aumento da quantidade gerada de produtos e serviços inovadores e do fluxo de conhecimento produzido e transferido para a sociedade, sugere-se que a estratégia de difusão da inovação para institutos de pesquisa pode ocorrer com maior eficiência da que ocorre atualmente. A compatibilização entre a produção, oferta e demanda do conhecimento científico por parte de institutos de pesquisa públicos no Brasil e empresas se dá pela multiplicidade de opções estratégias, como sugerida pela abordagem sistêmica, e com portfólio de modelos de negócios associados. Uma estrutura multicanais de distribuição pode contribuir com a eficiência da difusão da inovação por incorporar funções antes desenvolvidas por componentes da estrutura de canais nem sempre ágeis e/ou com competências específicas para gerir a inter-relação com empresas. Foi utilizada a grounded theory como metodologia que, para a categorização e posterior codificação axial, teve como base 63 fontes de dados, sendo 21 entrevistas e 42 palestras, resultado a criação de modelo teórico para difusão da inovação em institutos de pesquisa públicos no Brasil. / The proposed innovation diffusion model for public research institutes in Brazil suggests that the inter-relationship of research institutions and enterprises can occur differently from what has been observed in practice. More often than rare, one has been questioning NITs primacy on managing innovation policy research institutes to promote technology transfer and interaction with companies. Aiming to leverage the scientific development, by increasing the throughtput of innovative products and services and the flow of knowledge produced and transferred to the society, it is suggested that innovation diffusion strategy for research institutes can occur with higher efficiency than currently occurs. The compatibility between the production, supply and demand of scientific knowledge on the part of public research institutes and companies in Brazil is due to the multiplicity of possible strategies, as suggested by the systemic approach, portfolio and associated business models. A multichannel distribution structure can contribute to the efficiency of innovation diffusion by incorporating functions previously performed by components of channels not always agile and / or with specific skills to manage the relationship with companies. This study is based on the grounded theory as its methodology. For categorization and posterior axial coding purposes, it were used 63 data sources, being 21 interviews and 42 lectures, and as a result it was possible to elaborate a theoretical model for innovation diffusion for research institutes public in Brazil.
33

Identifying barriers to the implementation of bus policy at a local level in Great Britain using a decision support framework

McTigue, Clare January 2018 (has links)
The current debate on transport policy in the UK is focused on the need for a sustainable transport system. Buses play a vital role in achieving this, as they are the most frequently used and most accessible mode of public transport. However, the literature shows that the delivery of sustainable transport policies is not producing the desired outcomes (Hull, 2009) and the application of such policies in real situations remains inconsistent. This is evident across the UK where there has been a decrease in bus patronage and bus mileage. To address this gap, the aim of this research is to identify why bus policies are not imple-mented successfully at a local level and to provide recommendations for implementation and decision making that will aid policy makers, local authority staff, regional transport partnerships, bus operating companies and other practitioners working within the field of transport. A mixed methodology was chosen for this research and is divided into three key stages to address the research problem. The first methodology included an online ques-tionnaire and 143 questionnaires were sent to all public transport officers in Great Britain. 80 surveys were returned giving a response rate of 56%. The second methodology in-cluded telephone interviews conducted with 10 of those public transport officers who responded to the questionnaire in order to elicit a deeper understanding of the results, which could not be achieved from the questionnaire results alone. Finally, the third meth-odology included four case studies on specific bus schemes within Great Britain. These case studies were the Quality Contract Scheme in Tyne and Wear, Fastlink Scheme in Glasgow, Bus Priority Scheme in Solihull and Smart Ticketing Scheme in Dundee. While the questionnaires and telephone interviews provide an overview of bus policy imple-mentation across Great Britain, the multiple case studies were required to investigate the topic in depth, thus identifying the greatest barriers to bus policy implementation. Analysis of the three sets of data is based on the application of a new decision support frame-work developed in this research. The findings in this thesis reveal that local authorities in Great Britain are under-performing in the implementation of bus policy due to the barriers they face. The greatest barriers to implementation include the lack of a policy document; the characteristics of the organisation; availability of resources; intra-organisation support and communication; economic, social and political environments; and opposition, conflict, and ambiguities. Overall, this research has identified several concerns with bus policy implementation. The most obvious concern is the unclear link between policy objectives and measures and the setting and monitoring of performance targets. Meanwhile, the deregulation of the bus sector in the UK means that, in some cases, a lack of control over the implementation of certain measures places limits on policy implementation and results in the frequent im-plementation of policy measures that are achievable rather than those that are necessary to the achievement of policy objectives. The findings from this research also help policy-makers and transport planners to predict what makes implementation successful and to address problems and issues through improved policies and regulations, as well as to an-ticipate and plan for likely barriers. Moreover, addressing these barriers can help tackle the decline in bus mileage and bus usage across Great Britain.
34

Simulation Modeling of Karst Aquifer Conduit Evolution and Relations to Climate

Broome, John D 01 December 2008 (has links)
ABSTRACT Karst regions of the world that receive relatively similar amounts of precipitation display a wide variety of landscapes. It has been suggested (Groves and Meiman, 2005) that climates exhibiting larger discrete storm events have more dissolving power and consequently higher rates of conduit growth than climates with more uniform precipitation distributions. To study this concept, a computer program “Cave Growth” was developed that modeled the growth of a cross-section of a cave passage under dynamic flow and chemical conditions. A series of 46 simulation datasets were created to represent different climatic conditions. These simulations had the same total annual discharge, but demonstrated a range of flow distributions quantified by use of a gamma distribution index, along with two special theoretical cases. After simulating a year of conduit growth for each of the various flow distributions in a series of model runs, and repeating these sets of simulations for three different passage cross-section geometries, it was evident that the annual temporal distribution of flow did indeed impact the amount of cave growth. However, an increase in the “storminess” of the climate did not simply equate to more dissolution and thus conduit growth. Rather, the quantity and duration of surface contact between water and the conduit walls combined with dissolution rates to affect the total growth. The amount of wetted perimeter (contact between fluid and passage floor/walls) generated by specific conduit to capacity were shown to be very effective at growing the cave. Above this level, the dissolving power of additional water was essentially wasted. This investigation suggests that the maximum amount of passage flow levels depended upon the shape of the passage. Flow conditions that filled the growth occurs under flow conditions that result in the most wetted perimeter for the longest period of time at the highest dissolution rate.
35

The Hunted/r

Vice President Research, Office of the 06 1900 (has links)
Jeff Carroll's research into Huntington's disease is not only offering hope for the afflicted; it's changing the course of his own genetic destiny.
36

Modelo de difusão da inovação para instituto de pesquisa no Brasil / Innovation diffusion model for public research institute in Brazil

Cely Ades 26 June 2013 (has links)
A proposta de criação de um modelo de difusão da inovação para institutos de pesquisa públicos no Brasil sugere que o inter-relacionamento de instituições de pesquisa e empresas pode ocorrer de maneira diferente da que vem sendo observada na prática. Os NITs são questionados como modelo único para gerir a política de inovação dos institutos de pesquisa para promover a transferência de tecnologia e interação com empresas. Com o objetivo de alavancar o desenvolvimento científico, por meio do aumento da quantidade gerada de produtos e serviços inovadores e do fluxo de conhecimento produzido e transferido para a sociedade, sugere-se que a estratégia de difusão da inovação para institutos de pesquisa pode ocorrer com maior eficiência da que ocorre atualmente. A compatibilização entre a produção, oferta e demanda do conhecimento científico por parte de institutos de pesquisa públicos no Brasil e empresas se dá pela multiplicidade de opções estratégias, como sugerida pela abordagem sistêmica, e com portfólio de modelos de negócios associados. Uma estrutura multicanais de distribuição pode contribuir com a eficiência da difusão da inovação por incorporar funções antes desenvolvidas por componentes da estrutura de canais nem sempre ágeis e/ou com competências específicas para gerir a inter-relação com empresas. Foi utilizada a grounded theory como metodologia que, para a categorização e posterior codificação axial, teve como base 63 fontes de dados, sendo 21 entrevistas e 42 palestras, resultado a criação de modelo teórico para difusão da inovação em institutos de pesquisa públicos no Brasil. / The proposed innovation diffusion model for public research institutes in Brazil suggests that the inter-relationship of research institutions and enterprises can occur differently from what has been observed in practice. More often than rare, one has been questioning NITs primacy on managing innovation policy research institutes to promote technology transfer and interaction with companies. Aiming to leverage the scientific development, by increasing the throughtput of innovative products and services and the flow of knowledge produced and transferred to the society, it is suggested that innovation diffusion strategy for research institutes can occur with higher efficiency than currently occurs. The compatibility between the production, supply and demand of scientific knowledge on the part of public research institutes and companies in Brazil is due to the multiplicity of possible strategies, as suggested by the systemic approach, portfolio and associated business models. A multichannel distribution structure can contribute to the efficiency of innovation diffusion by incorporating functions previously performed by components of channels not always agile and / or with specific skills to manage the relationship with companies. This study is based on the grounded theory as its methodology. For categorization and posterior axial coding purposes, it were used 63 data sources, being 21 interviews and 42 lectures, and as a result it was possible to elaborate a theoretical model for innovation diffusion for research institutes public in Brazil.
37

Site selection and community participation in the development of Gracilaria Gracilts (stackhouse) steentoft, irvine and farnham mariculture in the Western Cape province, South Africa.

Brown, Bernadette January 1999 (has links)
Magister Artium (Development Studies) - MA(DVS) / The seaweed Gracilaria gracilis has been shown in previous studies to have potential for mariculture along the West Coast of South Africa. However, the selection of suitable sites is crucial for the success of a farming enterprise. The variables important in the success or sustainability of suspended raft culture, and the environmental factors influencing these variables, were identified through a literature review. A suitable site was defined as a site with surface water temperature of between 10 and 17 "C, water depth of between 2 and 10 m below surface, and wave heights of less than 4 m. Data and information about these factors were obtained from sources such as the Sea Fisheries Research Institute, the SADCO database, the CSIR and from volunteers in St Helena Bay. The objectives of this study were to convert available data into formats that could be used in a Geographical Information System (GIS), and to predict suitable and available sites for suspended cultivation of Gracilaria gracilis in Saldanha Bay, Langebaan Lagoon and St. Helena Bay. Data were converted to digital format and data layers created. Each data layer represented suitable and unsuitable areas. Areas with existing mariculture, harbours, ship traffic zones and other uses were excluded to determine the real available areas. The Saldanha Bay-Langebaan lagoon system and St Helena Bay, have sites that show potential for suspended cultivation of G. eracilis. The total sizes of the areas selected as suitable are 975.4 ha in Saldanha Bay and 474.8 ha in St. Helena Bay. Some sites predicted as suitable are located in areas known to be subject to conditions not suitable for seaweed mariculture, and led to the conclusion that the accuracy of input data or method of analysis must be improved.
38

The strategic management of a DERI

Smuts, Petrus Gerhardus 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The term DERI stands for Defence Evaluation and Research Institute. DERls are strategic institutes, established primarily to provide technological support to the Department of Defence. They are responsible for the cost-effective development, maintenance and application of advanced technologies and concentrate on specific application areas in the South African Defence Force, corresponding to the User Support Teams in the Armament Technology Acquisition Secretariat. The research problem is how to strategically manage such a DERI in terms of vision, mission, goals, structure of organisation, clients, alliances and resources such as funding, personnel, facilities and equipment, to optimally provide the best possible service to the main client, the DoD and in the process ensure the long term sustainability of the DERI. An interview was held with the senior executive manager of each of the five official DERls and also with two very knowledgeable persons on the subject of Defence and Evaluation Research management, with the aim of determining which attributes or factors they deem important in the strategic management of a DERI. The interviews were typed ver batim and all the attributes were included in a questionnaire. A few more attributes determined from literature and discussions with De Wet, were also added. Afterwards the abovementioned managers completed a questionnaire in which they indicated the relative importance of the various attributes. The attributes that scored the highest rating were grouped into clusters and are analysed accordingly. The clusters are as follows: • ''people" cluster since it is about the knowledge, skills and trust of people • ''value-for-money cluster since the attributes are about planning, funding and objectives • "you-have-to-earn-your-survival cluster since it is about disciplines, application of R&D and the right of existence of a DERI All three clusters are enlightened by the comments, remarks, suggestions and concerns raised during the interviews with the senior executive managers. People attributes came out as being the most critical success factor in the strategic management of a DERI. "People" can effectively be divided into two categories - the DERI's employees on the one hand and the clients' employees on the other. Everything concerning people is seen as important namely: training. remuneration, quality service (internal and external), trust, growth and development, communication, Black Economic Empowerment, stakeholder interface, etc. There is a concern about the longer-term survival of the DERls because they are currently situated in two different organisations in two different state departments with different visions, missions and goals. A clear indication of the road ahead should be given as soon as possible. A solution to the integration question would be an independent investigation by people who have no vested interests in the outcome of the decision. Whatever the final answer (one of the two current state departments or a new organisation or the slatus quo), both departments (Arts, Science and Technology and Defence) should not feel endangered and the solution should be a win-win situation for both parties. / AFRIKAANSE OPSOMMING: DERI is die verkorte vorm vir Defence Evaluation and Research Institute oftewel Evaluasie- en Navorsingsinstituut vir die Weermag. DERI's is strategiese institute wat daargestel is om tegnologiese ondersteuning aan die Departement van Verdediging te bied. DERI's is verantwoordelik vir die koste-effektiewe ontwikkeling, instandhouding en aanwending van gevorderde tegnologiee en fokus op spesifieke toepassingsareas in die Suid-Afrikaanse Weermag. Die ondersteuning vind plaas in ooreenstemming met die behoeftes van gebruiker ondersteuningspanne in die Wapen Tegnologie Aanskaffingsekretariaat. Die navorsingsonderwerp is hoe om 'n DERI strategies te bestuur in terme van visie, missie, doelwitte, struktuur van organisasie, kliente en bronne soos befondsing, personeel, fasiliteite en toerusting, Ten einde die bes moontlike diens aan die hoofklient, die Departement van Verdediging, te lewer en terselfdertyd die DERI volhoubaar te maak oor die lang termyn. 'n Onderhoud is gevoer met die senior uitvoerende bestuurder van elke DERI sowel as met twee baie kundige persone op die gebied van Verdedigingsevaluasie en Navorsingsbestuur. Die doel hiervan was om te bepaal watter faktore as die belangrikste in die strategiese bestuur van 'n DERI, beskou word. Die onderhoude is woordeliks getik en al die faktore aangedui, in 'n vraelys opgeneem. 'n Verdere aantal faktore, wat uit literatuurstudies en gesprekke met De Wet verkry is. is ook ingesluit in die vraelys. Die vraelys is aan die betrokke persone gestuur met die versoek om die relatiewe belangrikheid van die faktore aan te dui. Die faktore wat die meeste gewig dra, is in groepe saamgevoeg en sodanig ontleed. Die groeperings is as volg: • "mense" groepering aangesien dit handel oor kennis, vaardighede en onderlinge vertroue tussen mense • "waarde-vir-geld" groepering aangesien dit handel oor beplanning, befondsing en strategiese doelstellings • "moet-jou-oorlewing-verdien" groepering aangesien dit handel oor dissiplines, die toepassing van navorsing en ontwikkeling en die bestaansreg van 'n DERI Die drie groepe word toegelig deur kommentaar, opmerkings en voorstelle van die bestuurders tydens die onderhoude. Die "mens"-faktor is verreweg die belangrikste sukses faktor in die strategiese bestuur van 'n DERI. "Mense" kan in twee kategoriee verdeel word - die DERI se werknemers aan die een kant en die van die klient aan die ander kant. Alle aspekte rakende mense, word beskou as belangrik naamlik: opleiding, vergoeding, kwaliteit van diens (intern sowel as ekstern), vertroue, groei en ontwikkeling, kommunikasie, Swart Ekonomiese bemagtiging, kontak met belangehouers, ensovoorts. Daar bestaan onsekerheid oor die voortbestaan van die DERl's oor die langtermyn as gevolg van die feit dat hulle tans deel is van twee organisasies binne twee verskillende staatsdepartemente. Hierdie departemente het verskillende visies, missies en doelstellings. 'n Aanduiding van die pad vorentoe moet so gou as moontlik verskaf word.
39

Aufbereitung und Recycling in Freiberg

Heegn, Hanspeter 07 October 2016 (has links) (PDF)
Ausgehend von der mit der Bergakademie verbundenen Geschichte der Aufbereitung in Freiberg werden die 1954 erfolgte Gründung und die in der Zeit der DDR erfolgreiche Tätigkeit des Forschungsinstitutes für Aufbereitung (FIA) dargestellt. Auch nach der Schließung des Instituts 1991 wurden die Forschungsarbeiten in gemeinnützigen Vereinen und schließlich als UVR-FIA GmbH bis in die Gegenwart weitergeführt. Mit der 2011 erfolgten Gründung des Helmholtz-Instituts für Ressourcentechnologie (HIF) besteht die Hoffnung, dass im Gebäudekomplex des ehemaligen FIA in Kooperation mit UVR-FIA GmbH, die durch die Initiative von Prof. Helmut Kirchberg Anfang der 1950er Jahre in Freiberg begründete, außeruniversitäre Forschung zur Rohstoffnutzung eine würdige Fortsetzung am traditionellen Standort findet.
40

Field assessment of agronomic traits and in vitro acetolactate synthase characterisation of imazapyr herbicide tolerant sugarcane.

Maphalala, Kwanele Zakhele. January 2013 (has links)
Weed control is a major cost for growers in the sugarcane industry, especially for monocotyledonous species such as Cynodon and Rottboellia spp. The introduction of imazapyr-tolerant sugarcane would be advantageous as this herbicide has shown to be effective against the above-mentioned weeds but it also kills sugarcane. In a previous study in our laboratory, several sugarcane putative-mutant lines of variety N12 were generated by in vitro exposure of embryogenic callus to 16 mM ethyl methanesulfonate (EMS), followed by selection on imazapyr-containing medium. Tolerance to a low dose of imazapyr was confirmed in seven of those lines when the herbicide was applied (182 g a.i. ha-1) to 3 month-old plants in pots. The aim of the present study was to identify which of the seven herbicide mutant lines had agronomic characteristics at least equivalent to un-mutated N12. The objectives were to: 1) confirm tolerance to increased rate (312 and 625 g a.i. ha-1) of imazapyr in field plants; 2) measure the agronomic characteristics of these lines; 3) determine the effect of residual soil herbicide activity on germination of sugarcane setts. The seven mutant lines (Mut1-Mut7) and un-mutated N12 were clonally propagated in vitro by shoot multiplication followed by rooting and planted in three plots (untreated, sprayed with 312 or 625 g a.i. ha-1 imazapyr), in the field, in a randomized complete block design. In the untreated control plot there were no significant differences between the control and the mutant plants for agronomic traits (tiller number/plot, stalk height and stalk diameter) or estimated yield (kg/plot) after 10 months, indicating that the mutation process had no effect on general plant phenotype. In the sprayed (312 and 625 g a.i. ha-1) plots, Mut1, Mut4, Mut5, Mut6 and Mut7 plants showed tolerance to imazapyr as the leaves remained green compared with Mut2, Mut3 and N12 control plants, which displayed chlorotic leaves and eventually died in the plot sprayed with 625 g a.i. ha-1. Post-herbicide application, the yields of Mut5, Mut6 and Mut7 (52.33, 43.43 and 41.43 kg/plot, respectively) from the 312 g a.i. ha-1 plot were not significantly different from that of N12 control (53. 61 kg/plot) in the untreated plot. However, in the 312 g a.i. ha-1 plot, the yield and agronomic trait measurements of the untreated N12 control were significantly higher than those of the herbicide-susceptible plants Mut2 and Mut3. Similarly, in the 625 g a.i. ha-1 plot, the recorded yields for Mut4, Mut6 and Mut7 were 41.60, 43.44 and 36.30 kg/plot, respectively, indicating that their imazapyr tolerance and yield characteristics were comparable to the untreated N12 control. Imazapyr is conventionally applied to a fallow field 3-4 months prior to planting sugarcane as there is residual herbicide activity in the soil that suppresses sugarcane germination and growth. Therefore, in order to establish if the herbicide-tolerant mutants could germinate in iii an imazapyr-treated field, 3-budded setts of the mutant lines (Mut1-Mut7) and N12 control were planted in two plots, one unsprayed and one sprayed with 1254 g a.i. ha-1 imazapyr, 2 weeks previously. Germination was calculated after 3 weeks as the number of germinated setts in each plot/no. germinated setts in unsprayed plot x100. In the sprayed plot, the setts from Mut1, Mut4 and Mut6 displayed the highest germination percentages (60, 71 and 74%, respectively) compared with Mut2 (24%), Mut3 (46%), Mut5 (34%), Mut7 (40%) and the N12 control (12%). The in vitro acetolactate synthase (ALS) enzyme activity of 10 month-old plants from the untreated plot was assessed in the presence of 0-30 μM imazapyr to determine the herbicide concentration that inhibited ALS activity by 50% (IC50). The IC50 values for the mutated lines were between 3 and 30 μM, i.e. 1.5-8.8 times more tolerant to imazapyr than the N12 control plants, with Mut6 displaying the highest IC50 value (30 μM). On the basis of the results, it was concluded that Mut1, Mut6 and Mut7 lines were more tolerant to imazapyr than N12 and the other tested lines. Future work includes phenotypically assessing these lines for traits including sucrose content, fibre content, actual yield (tons cane ha-1) and altered pest and disease resistance. Once isolated and sequenced, the ALS gene conferring imazapyr tolerance can be used in genetic bombardment in the genetic modification approach as the gene of interest or as a selectable marker. In addition, the imazapyr-tolerant line can be used for commercial purposes in the field and as the parent plant in the breeding programme. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Durban, 2013.

Page generated in 0.039 seconds