• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1751
  • 1265
  • 459
  • 395
  • 185
  • 126
  • 61
  • 61
  • 49
  • 45
  • 36
  • 32
  • 27
  • 27
  • 27
  • Tagged with
  • 5481
  • 1171
  • 800
  • 684
  • 672
  • 443
  • 440
  • 440
  • 394
  • 365
  • 355
  • 317
  • 311
  • 290
  • 272
  • 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.
251

A Qualitative Approach Using the Self Determination Theory To Understand Motivation Within the Concept of Physical Literacy

McClelland, Kathryn A. 09 October 2013 (has links)
The relevance of motivation has saturated many physical literacy definitions (Mandigo et al., 2006); however, the study of motivation in this context has generated minimal attention. Thus, the purpose of this study was to explore motivation with respect to physical literacy related to self-reported variety of physical activity engagement and predilection towards physical activity. Participants included 218 male and female students in grades 4-6. Deci and Ryan’s (1985) basic needs theory guided a thematic analysis of open-ended questions from the Canadian Assessment of Physical Literacy. Results indicated participants’ engagement in a variety of physical activities, and predilection towards physical activity was influenced by self-reported need satisfaction. Competence related more to engagement in a wide variety of physical activities while relatedness was found to relate more to predilection towards physical activity. Children who engaged in their physical activities for fun, and health benefits on average participated in a greater variety of physical activities.
252

The Effects of Feedstock Pre-treatment on the Fluidized Bed Gasification of Biomass

Bronson, Benjamin 12 March 2014 (has links)
Gasification is a promising technique for transforming solid biomass into a gas that can be used to produce renewable heat, power, fuels or chemicals. Biomass materials, such as forestry residues, can be high moisture, heterogeneous mixtures with low bulk density - properties that make them difficult to handle and convert. Consequently, this means that feedstock pre-treatment is usually necessary in order to facilitate its conversion by gasification. Pre-treatments methods, which include comminution, drying, pelletization, torrefaction, or carbonization will affect the properties of the biomass which will affect their gasification in a fluidized bed. The objective of this thesis was to determine how biomass pre-treatment can influence gasification in a fluidized bed. A single forestry residue was processed using five pre-treatment process levels: sieving (as a surrogate for comminution), drying (moisture content), pelletization, torrefaction, and carbonization. The fractions derived from these processes were gasified in a small pilot-scale air blown bubbling fluidized bed gasifier (feed rate 8 – 25 kg/h). The particle size and form had an impact on the gas composition, tar content, and cold gas efficiency of the gasification. Over the conditions tested, the finest fraction produced a gas with a H2/CO ratio of 0.36 – 0.47 containing 7 – 59 g/m3 tar (gravimetric) at a cold gas efficiency of 30 - 41%. The pellets on the other hand yielded a gas with a H2/CO ratio of 0.89 - 1.14, containing 3 – 37 g/m3 tar (gravimetric) at a cold gas efficiency of 41 – 60%. Drying, torrefaction and carbonization also had an impact on the gasification performance. Carbonization was able to reduce the yield of tar (as measured by gas chromatography) by more than 95% relative to the parent material. Finally, four different forestry residues were gasified in a large pilot-scale bubbling fluidized bed with air and steam-oxygen mixtures (feed rate 200 – 245 kg/h) in order to assess whether the comminution effect could be observed at the large scale. One feedstock with a significant portion of small particles showed the expected effects compared to the feed materials with large feed particles: lower H2/CO ratio, greater tar yield, lower cold gas efficiency while the other feed material containing a substantial amount of small particles did not show these effects.
253

Pre-cooling during steady-state rowing decreases physiological strain and enhances self-paced rowing performance in elite rowers

Johnson, Elizabeth A.R. 31 December 2005 (has links)
To determine the effects of torso cooling with ice (ICE) or water-perfused (WP) vests during rest and warm-up on subsequent 1500 m time trial rowing performance in the heat. Eight male rowers (23 ± 4 y) completed 3 sessions on an ergometer in an environmental chamber (38ºC, 47% RH) 1 week apart. Pre-cooling was applied during rest (45 min) and warm-up (30 min) in 2 trials using ICE or WP vests, but not in the control condition (CON). Rectal (Tre) and skin (Tsk) temperature, HR, RPE, thermal comfort (TC) and sensation (TS) were monitored throughout. HR, RPE or TS were not different between conditions. TC, Tre and Tsk were lower in WP and ICE than CON post warm-up (P<0.05). The reduction in strain was reflected by increased power output during the 1500 m time trial in ICE (11±1.2 %) and WP (9.6±1.1%) compared to CON (P<0.05). Pre-cooling with ICE or WP vests enhanced performance in a 1500 m rowing time trial and power output was higher from the onset.
254

Urban inequalities : social geography and demography in seventeenth century York

Hibberd, Deborah Joan January 1981 (has links)
No description available.
255

The history of phantasmagoria

Heard, Mervyn January 2001 (has links)
No description available.
256

The influence of tumour angiogenesis on the metastatic potential of colorectal carcinomas

Khan, Humma January 2007 (has links)
Colon cancer is the fourth most common cause of cancer death in the world. It kills approximately 529,000 people annually and around two thirds of these deaths are in the developed world. These figures can be attributed to the fact that colorectal cancers are well advanced before they are detected. Effective prevention of the disease is early detection and removal of pre-cancerous polyps. In cases where cancer has already developed, early detection still significantly improves the chances of cure by surgically removing the cancer before the disease is able to metastasise. However, in metastatic colorectal cancers, in order to ascertain an effective treatment regimen and determine the prognosis of a patient after surgery a prognostic tool that accurately portrays the extent of the disease needs to be developed. Currently, the most commonly used prognostic tool to assess colorectal cancer spread is the clinicopathological staging system. However, there is a need for additional markers of metastasis as nearly one-third of patients with a clinical diagnosis of Dukes' B, a commonly used pathological staging system for colorectal cancer prognosis, will die of the disease despite complete resection of the primary tumour. In several human cancers such as breast, prostate and the lung, tumour vascularity has been shown to be of prognostic value. However, studies correlating the significance of the number of tumour vessels to prognosis in colorectal cancers are relatively lacking or show conflicting results. Moreover, it is not yet fully understood if factors involved in the complicated cascade of tumour blood vessel formation (tumour angiogenesis), such as proteases cathepsin B and dipeptidyl peptidase IV aid colorectal cancer progression. Two of the most potent angiogenic growth factors: vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) playa significant role in the development of tumour vessels; however, their influence on the production of these proteases is not clear. Therefore, this study set out to i) establish a reliable method to quantify colorectal tumour vessels ii) to assess the correlation between vessel counts and prognostic parameters associated with metastasis iii) to ascertain the pattern of spatial distribution of tumour vessels in order to defme the relationship between the positions of the vessels in relation to areas of tumour growth iv) investigate the levels of the enzyme expression of tumour associated proteases cathepsin B and dipeptidyl peptidase IV, at both protein and mRNA level, in colorectal tumours of varying clinicopathological grades and to v) assess the influence of VEGF and bFGF on CB and DPPIV proteolytic enzyme activity in human colon, rectal cancer cells and normal human umbilical vein endothelial cells. The study established that an effective method to examine tumour vascularity, was by immunolocalising tumour endothelial cells by CD31 and quantifying all of stained vessels present within each cross-sectional area. As a result of tumour endothelial cell marker assessment it was noted that CD34 was highly specific to certain vessels and distinctly immunonegative to others and that the same vessels were positive to CD31. These vessels were morphologically assessed by using the standard histological criteria identified as lymph vessels. Tumour blood and lymph vessels were quantified and a positive correlation to prognostic parameters relating to cancer spread was identified. The pattern of distribution of colorectal tumour vessels was also examined and a distinct pattern was observed in metastatic tumours with greater numbers of vessels in the peripheral regions and the invasive fronts. Qualitative analysis of protease expression and mRNA intensity, in colorectal tumours, revealed increased levels of CB and DPPIV in tumours with clinicopathological parameters associated with metastasis. mRNA localization near tumour vessels highlighted the potential for, not only cancer cells but also tumour endothelial cells, to produce proteolytic enzymes to aid the process of tumour angiogenesis and hence tumour growth and metastasis. The study also demonstrated that the angiogenic factors VEGF and bFGF up-regulated CB and DPPIV activity in human colon, rectal cancer cells and normal human umbilical vein endothelial cells.The presence of tumour lymph vessels and their positive correlation to metastatic parameters signifies an important role for such vessels in the process of colorectal cancer spread. The positive relationship of tumour blood vessels to parameters associated with metastasis re-instates the important role of tumour angiogenesis in colorectal cancer. Other factors that were investigated such as tumour associated proteases CB and DPPIV and the influence of the potent angiogenic proteins upon their activity suggests that these factors have a direct role in colorectal cancer metastasis. Therefore, it can be concluded from the results of this thesis that tumour blood vessel counts can be used as a reliable prognostic marker in colorectal cancer. Tumour angiogenic factors as well as the colorectal tumour lymph vessels have the potential to be used as additional prognostic markers in clinical prognostic evaluations. This has important implications in allowing clinicians to accurately assess post-operative survival rates and to devise an effective treatment regimen in order to prolong the lives and possibly cure colorectal cancer patients.
257

”Man blir specialist på sitt barn" : En studie kring hur sex föräldrar till barn i behov av särskilt stöd upplevt kontakten med förskolan

Nestius, Siri, Ahrén, Linda January 2014 (has links)
The purpose of this study is to increase understanding of how parents of children in need of special support have experienced their interaction with the pre-school. Our three main areas of interest were to investigate how several parents experienced their contact with the pre-school, if there were any experienced factors that had played a part in the contact with the pre-school and if we could conclude anything about how the curriculum had been followed in these cases, with assistance of the parents’ experiences. Our study is qualitative and we chose to interview six parents. We both participated in all of the interviews. The theoretical base of this study is rooted in the phenomenological theory and we also used the framework factor theory to complement our analysis. One of our conclusions was that the parents expressed so many different experiences that we decide not to try compare them in general. On the other hand, all of the parents expressed that they were the ones who knew their children best and due to that, another conclusion that we interpreted was that the pre-school educators should pay attention to the parents so as to ensure that their contact would work as well as possible.
258

Fine resolution pollen analysis of late Flandrian II peat at North Gill, North York moors

Innes, James B. January 1989 (has links)
Pollen and charcoal percentage and concentration analyses have been conducted upon several upland peat profiles of late Flandrian II and early Flandrian III age at North Gill, North York Moors, where earlier research had proven recurrent major pre Elm Decline woodland disturbance, supported in one profile by radiocarbon dating. Fine temporal resolution pollen analysis (FRPA) involving the use of contiguous millimetre sampling was applied to Flandrian II disturbance phases at five of the North Gill profiles. At North Gill 1A a further phase of disturbance near the end of Flandrian II was examined using FRPA to study evidence of pre Elm Decline agricultural activity, and at this profile both the horizontal and vertical resolution limits of the technique were tested by progressively finer sub-sampling. The millimetre level FRPA analyses showed that each of the examined pre Elm Decline disturbance phases was an aggregate feature, composed of a number of smaller sub-phases, the ecological effects of which in terms of spatially-precise woodland successions and community structures were assessed and contrasted. Inter-profile spatial comparison of the ecology of woodland disturbances has been made at both FRPA and conventional scales of temporal resolution. FRPA study of the late Flandrian II disturbance phase at North Gill 1A showed that cereal cultivation had occurred prior to the Elm Decline as part of a multi-phase period of agricultural land-use activity. The high resolution spatial and temporal data from North Gill have shown FRPA to be a most sensitive palaeoecological technique, and are discussed in relation to the effects of disturbance upon mire and woodland ecosystems, Mesolithic land-use, pre Elm Decline cereal cultivation and early Neolithic land-use.
259

Newborn Screening Education: A Survey of Ontario Mothers

Araia, Makda 27 October 2011 (has links)
Purpose and methods: Effective parental education about newborn screening (NBS) may help to maximize the benefits and minimize the harms of screening. We investigated experiences, knowledge and opinions regarding NBS education among Ontario mothers. Mothers whose infants recently received NBS were invited to complete a mailed survey (n=1712). Results: Of the 750 participants, 93% recalled their infant receiving NBS, while 69% recalled receiving information about NBS. Of this group, fewer than 50% reported receiving information prenatally, yet a majority of mothers (64%) viewed this as the most important time for education. Those who received information prenatally reported higher satisfaction (OR 2.4). The 40% of mothers who recalled being informed about the meaning of results had higher knowledge about NBS (OR 2.7) and reported higher satisfaction (OR 4.2). Conclusions: Parental education about NBS could place greater emphasis on the prenatal period and on fostering understanding about the meaning of results.
260

Device driver reuse via virtual machines

LeVasseur, Joshua Thomas, Computer Science & Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Device drivers constitute a significant portion of an operating system's source code. The effort to develop a new driver set is a sobering hurdle to the pursuit of novel operating system ventures. A practical solution is to reuse drivers, but this can contradict design goals in a new operating system. We offer a new approach to device-driver reuse, with a focus on promoting novel operating-system construction, which insulates the new operating system from the invariants of the reused drivers, while also addressing development effort. Our solution runs the drivers along with their original operating systems inside virtual machines, with some minor reuse infrastructure added to the driver's operating system to interface with the rest of the system. This approach turns the drivers into de-privileged applications of the new operating system, which separates their architectures and reduces cross-influences, and improves system dependability. Virtual machines help reuse drivers, but they also penalize performance. The known solution for improving virtual machine performance, para-virtualization, modifies the operating system to run on a hypervisor, which has an enormous cost: substantial development effort, and abandonment of many of virtualization's benefits such as modularity. These costs contradict our goals for driver reuse: to reduce development effort, and to easily reuse from a variety of operating systems. Thus we introduce a new approach to constructing virtual machines: pre-virtualization. Our solution combines the performance of para-virtualization with the modularity of traditional virtual machines. We still modify the operating system, but according to a set of principles called soft layering that preserves modularity, and via automation which reduces implementation costs. With pre-virtualization we can easily reuse device drivers. We describe our driver-reuse approach applied to a real system: we run virtual machines on the L4Ka::Pistachio microkernel, with reused Linux drivers. We include an evaluation and demonstrate that we achieve throughput comparable to the native Linux drivers, but with moderately higher CPU and memory utilization. Additionally, we describe how to apply pre-virtualization to multiple hypervisor environments. We include an evaluation of pre-virtualization, and demonstrate that it achieves comparable performance to para-virtualization for both the L4Ka::Pistachio and Xen hypervisors, with modularity.

Page generated in 0.0563 seconds