Towards molecular tools for management of oak forests : genetic studies on indigenous Quercus robur L., and Q. petraea (Matt.) Liebl. populations

This thesis describes the genetic composition of indigenous oak populations in the Netherlands using two different molecular marker techniques, AFLP and microsatellites. No diagnostic AFLP marker was found that could differentiate between Q. robur and Q. petraea, but five species-indicative AFLP markers were observed. This indicates that the two oak species are closely related. AFLP and microsatellite analysis of an ancient woodland described large Q. robur and Q. petraea clones with diameters up to 5.8 m. Such large clones are an indication for the old age of such woodlands that have a history of coppicing and grazing. As indigenous oak populations in the Netherlands suffered from large scale deforestation and have been coppiced and grazed for centuries, it was expected that the genetic variation of such populations would be low. However, the genetic variation observed for two indigenous Q. robur populations was as high as for unmanaged French and German Q. robur populations. Molecular markers that are closely linked to quantitative trait loci (QTLs) controlling eco-physiological and morphological traits can be used in ecology and forestry. Therefore, a genetic linkage map of Q. robur was constructed and QTLs controlling eco-physiological and morphological traits were located

Numerical Relativity Beyond General Relativity

Einstein’s theory of general relativity has passed all precision tests to date. At some length scale, however, general relativity (GR) must break down and be reconciled with quantum mechanics in a quantum theory of gravity (a beyond-GR theory). Binary black hole mergers probe the non-linear, highly dynamical regime of gravity, and gravitational waves from these systems may contain signatures of such a theory. In this thesis, we seek to make gravitational wave predictions for binary black hole mergers in a beyond-GR theory. These predictions can then be used to perform model-dependent tests of GR with gravitational wave detections. We make predictions using numerical relativity, the practice of precisely numerically solving the equations governing spacetime. This allows us to probe the behavior of a binary black hole system through full inspiral, merger, and ringdown. We choose to work in dynamical Chern-Simons gravity (dCS), a higher-curvature beyond-GR effective field theory that couples spacetime curvature to a scalar field, and has motivations in string theory and loop quantum gravity. In order to obtain a well-posed initial value formalism, we perturb this theory around GR. We compute the leading-order behavior of the dCS scalar field in a binary black hole merger, as well as the leading-order dCS correction to the spacetime metric and hence gravitational radiation. We produce the first numerical relativity beyond-GR waveforms in a higher-curvature theory of gravity. This thesis contains additional results, all of which harness the power of numerical relativity to test GR. We compute black hole shadows in dCS gravity, numerically prove the leading-order stability of rotating black holes in dCS gravity, and lay out a formalism for determining the start time of binary black hole ringdown using information from the strong-field region of a binary black hole simulation.</p

Reports of planetary astronomy, 1991

A collection is presented of summaries designed to provide information about scientific research projects conducted in the Planetary Astronomy Program in 1990 and 1991, and to facilitate communication and coordination among concerned scientists and interested persons in universities, government, and industry. Highlights of recent accomplishments in planetary astronomy are included

Sustainable Food Production and Consumption

According to the Food and Agriculture Organization of the United Nations, one-third of the world’s food produced for human consumption is lost or discarded. Meanwhile, the world needs to create a sustainable food future to feed the more than 9 billion people that are expected to inhabit the planet by 2050. The United Nations’ Sustainable Development Goals represent a global agenda for improving sustainability at a global level, and one of these goals (goal 12) is devoted to ensuring sustainable production and consumption patterns. This Special Issue intends to unify multidisciplinary areas of knowledge, under the sustainability pillar, based on knowledge about one of the most relevant agents for overall environmental impacts: food production and consumption. Therefore, the aim of this Special Issue is to highlight sustainability assessment in the contexts of agri-food production, food consumption, and food waste reduction to meet the needs of updating knowledge and developing new skills required by multiple social and economic agents. Food waste implies significant economic losses, ethical and social issues, adverse environmental effects, and considerable nutritional consequences, posing a threat to global sustainability. The purpose of this issue is to shine a light on the significance of research and practical initiatives engaged in the United Nations Agenda 2030 for Sustainable Development, specifically in protecting the planet by promoting sustainability in food production and consumption aiming at informing and influencing policy and practice globally

Hydrological connectivity in selected pristine catchments in the Kruger National Park.

M. Sc. Eng. University of KwaZulu-Natal, Pietermaritzburg 2014.The understanding of interactions between hydrological processes is essential, especially in water limited ecosystems in semi-arid environments. It is through this understanding that informed planning and management decisions for ecosystem conservation are developed. Assessment of groundwater- surface water connectivity at catchment scale provides a holistic view of the abiotic template that sustains life systems within the catchment. Spatial differences in hydrological responses are thus understood since these are characterised by nonlinearities emanating from catchment heterogeneity across spatial and temporal scales. This study involved an assessment of groundwater-surface water interaction across incremental contributing areas which were based on stream orders. The study areas, Southern Granites and Southern Basalts, are located on the two dominant geologies in the Kruger National Park (KNP). At Southern Granites the 1st order, 2nd order and 3rd order contributing catchments have an area of 0.3km2, 0.9km2 and 1.5km2 respectively. At the Southern Basalts site the areas for similar incremental catchments were 15.4km2, 31.6km2 and 47.8km2 respectively. Both study sites had streamflow levelloggers installed at each outlet the 1st to 3rd order contributing areas. The assessment was done through a combination of hydrometric techniques, Electrical Resistivity Tomography (ERT) and tracer analysis methods. Monitoring of water levels and sampling in the stream, riparian boreholes and piezometers was conducted from September 2012 to May 2013. The monitoring network consisted of 28 piezometers and 19 boreholes at Southern Granites while 6 piezometers and 4 boreholes were installed at the Southern Basalts sites. Streambed hydraulic conductivities were determined using slug tests. Hydraulic gradients between the stream, piezometers and groundwater boreholes were calculated and used to determine direction of fluxes. Connectivity mechanisms were determined and contributions of different water sources to streamflow were quantified using two and three component tracer based hydrograph separations. Results showed that rainfall intensity was the major control to connectivity between surface and groundwater resources in these catchments. Contribution of event water to streamflow was estimated between 60% and 86% across the nested spatial scales for two monitored rainfall events (19 January and 20 February 2013) at Southern Granites study site. Although event water emerged as the dominant source at all scales, higher pre-event contributions were noted for lower order subcatchments at this site. A 2nd order stream channel, previously conceptualised as gaining was demonstrated through hydrometry and tracers to be increasingly losing subsequently behaving as an indirect recharge point at Southern Granites site. The study, therefore, revealed that lower order reaches on the granitic geology are important water sources that sustain baseflow at higher order perennial streams. At Southern Basalts study site limited subsurface contribution to streamflow was observed due to very low interfluvial gradients and low aquifer transmissivities that characterise the basalt geology. Assessment of groundwater-surface water interaction at this site was conducted only at the 3rd order catchment due to a limited network of groundwater boreholes. At this reach the contribution of event water was estimated between 51% and 64% for two monitored events (19 January and 20 February 2013). Groundwater contribution to streamflow through localised preferential fractured rock flow ranged between 36% and 49%

Middle schools: a sociological interpretation of their development and practice

Middle schools as separate and distinct institutions are still a relatively recent feature in the maintained school system in England. This new category of schools is not a homogeneous one. The two main types of middle school tater for pupils aged either 8 - 12 or 9 - 13 years, but there are other variants whose pupils are in the age range 9 - 12, 10 - 13 and 10 - 14 years. Administratively middle schools are 'deemed' either primary or secondary. First, this study sets out to analyse the development of middle schools in England within the context of comprehensive secondary school re-organisation. Then the decision to adopt middle schools of different types in two L.E.A.'s is examined in some detail. The intention is to explore how far decision making at the L.E.A. level about the form of school systems illustrates the considerations which appear to operate at the level of central government. In the second part, aspects of life in two specific middle schools are explored from the points of view of teachers and pupils. Again the intention is to explore how far and in what ways issues relating to middle school planning at the central and local government level make their impact in particular schools. The central theme throughout this study is the degree of congruence between the rhetoric used to legitimate middle schools and the reality experienced within them. The problem of linking 'macro' and 'micro' levels of analysis is a familiar and persistent one in the sociology of education. In this study a theoretical synthesis to link decisions made about middle schools at central, government, local education authority and school ,level is made by way of an adaptation of exchange theory. It is suggested that this theoretical stance both clarifies and illuminates the data presented in the thesis and provides a framework in which future middle school developments can be located and interpreted