• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2763
  • 1484
  • 659
  • 395
  • 284
  • 99
  • 83
  • 65
  • 59
  • 56
  • 45
  • 42
  • 31
  • 31
  • 31
  • Tagged with
  • 7669
  • 1056
  • 706
  • 705
  • 675
  • 621
  • 606
  • 551
  • 497
  • 493
  • 442
  • 428
  • 421
  • 401
  • 369
  • 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.
701

Caractérisation de l'exposition aux pyréthrinoïdes dans la population rurale agricole de la Montérégie

Couture, Caroline January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
702

Le français au Québec : école, travail et foyer

Bouchnafa, Jalil January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
703

Spatial dynamics of cyclic field vole, Microtus agrestis, populations

MacKinnon, James L. January 1998 (has links)
1. Many ecologists have recently advocated the study of spatial patterns of abundance or growth rates as a means of better understanding population dynamics. In this study I described the spatial pattern of abundance of the field vole, Microtus agrestis, which has previously been shown to have cyclic temporal fluctuations of abundance in my study area in Kielder Forest, northern England. A combination of techniques was then used to investigate which processes determine the spatial pattern of dynamics in these vole populations.2. Previous analysis of spatial patterns in density of field voles from an area of approximately 80 km2 within Kielder forest over a 13-year period indicate that density varies as a periodic travelling wave moving across the landscape. I collected data on vole density from a larger area (approximately 600 km2) over a 2.5-year period and used the same analysis to show that the spatio-temporal variation in density was well explained by a travelling wave of density moving across the entire region. Estimates of the wave's speed of 14 kmyr-1 and direction of 66° from north were consistent with the estimates obtained from the data set covering a smaller spatial extent but spanning a longer temporal scale.3. Processes that determine population abundance do so by acting on vital demographic rates. Spatial patterns in demographic rates were therefore described to help identify potential causes of the spatial patterns of density. Eight 0.3 ha live-trapping grids were established within the study area and animals were trapped at monthly intervals during a period of extended low density and during a period of increasing densities. Capture-mark-recapture techniques were used to estimate abundance, juvenile recruitment rate, apparent survival rate and immigration rate at these sampling sites. The synchrony of changes in these parameters between sites was measured as the cross-correlation coefficient between the time series of each parameter and the spatial patterns in the synchrony of each demographic rate were described using Mantel correlations. Field vole abundance, juvenile recruitment rate and a derived estimate of mortality rate were most synchronous between the closest sites, however no directionality was found in these patterns and they could not therefore be related to the travelling wave pattern of density. I concluded that the process responsible for the wave probably only acted during the period of declining density and that therefore the factors causing spatial patterns in abundance could differ at different stages of the population cycle.
704

Small scale genetic and morphological structure in an island population of European starlings (Sturnus vulgaris)

Walkup, Jessica A. January 2013 (has links)
Variation in morphology and genotype among individuals of the same species occurs almost everywhere in the natural world. Such variation underlies natural selection and any resulting evolution, and therefore needs to be quantified in order to predict and understand phenotypic and evolutionary dynamics. Where morphology or genotype vary non-randomly in space, structured spatial variation can arise. Such spatial variation can arise from, and cause, further evolutionary processes including local adaptation and speciation. Here, I quantify spatial variation in neutral genetics and morphology, and in selection on morphology, occurring at a very small spatial scale within a single population of European starlings (Sturnus vulgaris) resident to the Island of Fair Isle. I demonstrate weak but statistically significant genetic structure in microsatellite loci by FST comparison but that similar structure is not supported by Bayesian cluster analysis. I also show significant genetic structure between populations of starlings within the UK from England, Scotland, Colonsay, Orkney and Shetland, and show that there are two main genetic clusters supported by Bayesian cluster analysis. I show there are significant differences in weight, tarsus lengths, bill lengths, bill size and, body condition among three, spatially proximate, spatial areas within Fair Isle thereby demonstrating significant small-scale spatial variation in morphology within this island population Using capture mark recapture analysis to estimate survival probabilities I evidence the occurrence of stabilizing selection on weight and disruptive selection on tarsus length in starlings but find no evidence that selection on morphology differed between sexes or among areas within Fair Isle. I conclude that small scale spatial variation in morphology and neutral genetics can occur on small spatial scales even in species with high potential mobility and where there are no distinct differences in environment and movement is not physically inhibited.
705

Rural sociability in the digital world

Wilson, Ruth January 2015 (has links)
The nature of sociability in the digital world has attracted much attention, with theories of the network society describing the formation of networked connections across distant geographies. Policymakers are optimistic about the potential for these new forms of connectivity to overcome some of the longstanding disadvantages of rural life. However, a prerequisite for full and meaningful participation in the network society is equal access to digital infrastructure, and a persistent urban–rural divide in this regard has been documented across Britain. The thesis argues that the meaning of the divide has been under-investigated with the result that our understanding of rural sociability in contemporary society is theoretically underdeveloped. This is addressed through a study of sociability in rural Britain, which adopts a “facet methodology” approach, examining the research problem from different angles using a range of methods. The first facet of the research compares the perceptions of rural and urban Internet users through an analysis of the Oxford Internet Survey. The second facet conducts a social network analysis of the online connections formed by a group of bloggers in the Scottish islands. The third facet explores the discursive interactions of the same set of bloggers through a thematic analysis of their writings. Together, the methods shed light on key aspects of the research problem. The findings reveal that people living in the country's rural areas are experiencing a different relationship with digital technology from urban residents. Rather than occupying peripheral or inferior positions in the network society, however, they are cultivating unique forms of digital sociability, informed by particular influences and motivations that set their social behaviour apart from the networked norm. Throughout the thesis, an understanding of the place of rural in the digital world is elaborated and the network society is shown to be differentiated across multiple dimensions.
706

Pharmacocinétique de population de la marbofloxacine chez le cheval

Peyrou, Mathieu January 2003 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
707

The role of migration in demographic development in the East Kazakhstan Region

Sagynbayeva, Ayaulym January 2010 (has links)
No description available.
708

Petroleum production and population change in north central Kansas

Harding, Jack Eugene January 1961 (has links)
No description available.
709

Future Population and Human Capital in Heterogeneous India

KC, Samir, Wurzer, Marcus, Speringer, Markus, Lutz, Wolfgang January 2018 (has links) (PDF)
Within the next decade India is expected to surpass China as the world's most populous country due to still higher fertility and a younger population. Around 2025 each country will be home to around 1.5 billion people. India is demographically very heterogeneous with some rural illiterate populations still having more than four children on average while educated urban women have fewer than 1.5 children and with great differences between states. We show that the population outlook greatly depends on the degree to which this heterogeneity is explicitly incorporated into the population projection model used. The conventional projection model, considering only the age and sex structures of the population at the national level, results in a lower projected population than the same model applied at the level of states because over time the high-fertility states gain more weight, thus applying the higher rates to more people. The opposite outcome results from an explicit consideration of education differentials because over time the proportion of more educated women with lower fertility increases, thus leading to lower predicted growth than in the conventional model. To comprehensively address this issue, we develop a five-dimensional model of India's population by state, rural/urban place of residence, age, sex, and level of education and show the impacts of different degrees of aggregation. We also provide human capital scenarios for all Indian states that suggest that India will rapidly catch up with other more developed countries in Asia if the recent pace of education expansion is maintained.
710

Water utilization and population demography in South Africa: key ethical and human rights issues

Mugabi, Brian 23 September 2010 (has links)
MMed,Bioethics and Health Law, Faculty of Health Sciences, University of the Witwatersrand / Access to sufficient water is a constitutionally recognized right in the Republic of South Africa as well as being a Universal Human Right. Despite this however, the world wide population numbers are ever growing and water is known to be finite. The Constitution’s Bill of Rights gives South African citizens the right to reproductive choices. South Africa is a water stressed country, with three forces feeding into availability of freshwater, namely; climate change, demographic factors, and policies. Currently, the problem of accessing safe freshwater is under question. This is presents a problem as the Constitution also addresses the right to a healthy environment. Uncontrolled population growth is detrimental to environmental integrity. It is arguable as to whether it is possible to conserve the environment, and at the same time realize human reproductive rights as envisioned in the Constitution. In this research report I reflect on the state of water and environmental resources in view of the right to procreate. I suggest that environmental education could play a major role in finding “the right balance”.

Page generated in 0.0762 seconds