It is increasingly argued that we are entering into a “biotech century”, in which biotechnology promises major advances in agricultural productivity. The development of biotechnology is not a straightforward affair, however, and the advent of GMOs has led to public protest and consumer resistance. This paper draws upon a comparative Australian-UK project concerned with the role of regulation and governance in mediating the debates and managing the associated risks. Regulatory responses and the mediation of conflicts by the Australian and UK governments have been shaped by the institutional and policy environments in these two countries. The implications of these public debates and regulatory responses for the capture of competitive opportunities are considered. The fact that the two countries have broadly similar systems of governance and regulation reveals how alike the circumstances are in many respects. But at the same time there are important differences in both the style and the content of the policy debates. In both the UK and Australia, the respective central governments remain committed to a ‘biotechnology future’. Against this background, there is little doubt that the choices about biotechnology will play a defining role in shaping the future of rural places. 相似文献
This paper will describe an enhancement to the GPS double difference carrier phase measurements on a single airborne platform
by smoothing them with inertial measurements while preserving the dynamic bandwidth. This enhancement will reduce the impact
of carrier phase multipath and carrier phase noise on baseline determination between multiple antennas on an aircraft when
in flight. This type of measurement system has numerous applications where platform pointing and relative body motion must
be determined at the mm-level for applications such as sensor stabilization, Synthetic Aperture Radar, long range RADAR (i.e.
angle-of-arrival measurements). Lower noise levels (mm-level and below) enable more performance to the stabilized system such
as increased aperture for longer range, operation at higher frequencies, and more image resolution. The focus of this paper
will be on a technique to provide this enhanced performance for these various applications using the available navigation
systems. Additionally, this type of smoothing can effectively remove the additional noise induced by carrier phase measurement
differencing. The noise level of a double or triple difference can be reduced below that of the raw measurement. A complimentary
synthesized double difference quantity with ultra-low-noise characteristics will be used to smooth the GPS carrier phase double
difference measurements without losing dynamic bandwidth since it follows the airborne dynamics. Flight test data will be
presented to demonstrate the performance improvement in the midst of aircraft dynamics. Results will show that the noise reduction
follows the theoretical prediction. 相似文献
A numerical model is described for coupled flow and mechanical deformation in fractured rock. The mechanical response of rock joints to changes in hydraulic pressure is strongly influenced by the geometric characteristics of the joint surfaces. The concept of this work is to combine straightforward finite element solutions with complex and realistic fracture surface geometry in order to reproduce the non-linear stress-deformation-permeability coupling that is commonly observed in fractures. Building on the numerous studies that have expanded the understanding of the key parameters needed to describe natural rough-walled fractures, new methods have been developed to generate a finite element mesh representing discrete fractures with realistic rough surface geometries embedded in a rock matrix. The finite element code GeoSys/Rockflow was then used to simulate the coupled effects of hydraulic stress, mechanical stress, and surface geometry on the evolving permeability of a single discrete fracture. The modeling concept was experimentally verified against examples from the literature. Modeling results were also compared to a simple interpenetration model. 相似文献
While the physical forcing mechanisms that govern the outflows of major rivers throughout the world are well documented in the literature, comparably less research has been done to examine the mechanisms that govern the contributions of small rivers and streams to coastal ocean systems. These rivers and streams provide a direct means for the transport of anthropogenic and terrigenous materials from watersheds to coastal oceans. This study describes the temporal and spatial variability of freshwater plumes from Kaneohe Stream, Hawaii, USA, after storm events in the Kaneohe Bay watershed. Freshwater plumes were examined using a combination of fixed moorings, synoptic shipboard surveys, and lagrangian surface drifters. Data sets were collected over the course of 19 months from August 2005 to March 2007 with particular attention paid to storms during the boreal winters. Stream discharge and duration were found to exert a primary control on plume persistence in the southern Kaneohe Bay system. Time series data show a strong coherence between wind forcing and surface currents, which, in combination with data derived from shipboard and aerial surveys, indicate that the spatial variability of freshwater plumes is primarily determined by atmospheric forcing. 相似文献
Ethiopia experiences significant climate-induced drought and stress on crop and livestock productivity, contributing to widespread food insecurity. Here, we present subseasonal crop water stress analyses that indicate degrading, growing conditions along Ethiopia’s eastern highlands, including productive and populated highland regions. These seasonally shifting areas of increasing water stress stretch from the north to south across eastern Ethiopia, intersecting regions of acute food insecurity and/or high population. Crop model simulations indicate that between 1982 and 2014, parts of eastern Amhara and eastern Oromia experienced increasing water deficits during the critical sowing, flowering, and ripening periods of crop growth. These trends occurred while population in these regions increased by 143% between 2000 and 2015. These areas of enhanced crop water stress in south-central Ethiopia coincide with regions of high population growth and ongoing crop extensification. Conversely, large regions of relatively unpopulated western Ethiopia are becoming wetter. These areas may therefore be good targets for agricultural development. 相似文献
In the current climate of economic restructuring, technological change and demographic transition, cities such as Melbourne are experiencing new and different pressures. That these pressures are exerted upon an already developed urban structure, and within a particular planning and administrative structure, means that outcomes vary from city to city. However, Melbourne, in common with a number of cities, is facing substantial changes in many aspects including the nature and location of economic enterprise, the structure and composition of the population, and the relative competitive strength of the region. The result is that Melbourne has experienced problems both in its ability to hold and continue to attract activities which provide a basis for further growth and development, and in the exacerbation of internal variations in the level of opportunity and quality of life available to different groups in the population.
The role of government has traditionally been relatively minor in guiding the process of urban development in Australia. However, since 1982 the state government in Victoria has made a concerted effort to reorganise and coordinate urban management and planning, integrating these with other strategic initiatives relating to economic development and social justice. While there is evidence that many of the initiatives are proving effective, there are still a number of problem areas. Some of these, such as global economic trends, are beyond the scope of government to control. Others, such as measures to facilitate the development of new economic activities, are within the power of government, but require careful formulation and management. The extent to which such measures are successful depends upon both the correct identification of problems and solutions, and the ability of government to gain a wide degree of acceptance of its goals. It is these that will prove the most difficult to achieve in the long run. 相似文献
Summary In this article, we argue that the spatial reorganization of local government structures may pose a significant threat to fragile local cultures. A recognition at the national level that policy structures are culturally specific (and not converging) is not always conceded at the very local level. Drawing on observations from Wales, we show how political change brings the danger of cultural neglect. 相似文献
This paper describes work undertaken and sponsored by the Energy Commission to improve transportation energy demand forecasting
and policy analysis for California. Two different, but related, modeling systems are presented: the Vehicle Transactions Simulator
and the Activity and Mobility Simulator. In addition, the paper discusses some of the important energy issues and analysis
that will be addressed in the next few years with the help of these models.
This paper was prepared as the result of work at the California Energy Commission. It does not necessarily represent the views
of the Energy Commission, its employees, or the State of California. 相似文献
A computational scheme has been constructed for solving the equations that describe strong thermal convection in a two-dimensional gas layer that is heated from below and is stratified across many scaleheights by a uniform gravitational field. The purpose of this scheme is to mimic the physical conditions that may have existed in a section of the proto-solar cloud from which the planetary system formed. The vertical temperature gradient of the initial quiescent layer of diatomic gas is strongly superadiabatic and matches that of a polytrope of index m = 1. The temperature at the upper boundary is kept fixed during the computation. Because of the highly compressible nature of the gas and the steep spatial gradients, a modified version of a flux-corrected transport scheme due to Zalesak is devised. The computations show that after the convection adopts a steady-state configuration, the flow consists of horizontal pairs of giant convective cells of opposing circulation. At the cell boundaries, the downflows are rapid and spatially concentrated while the upflows are broad and sluggish. Supersonic speeds are easily achieved in the downflows. Contrary to the expectations of the mixing length theory of convection, there is a net downward flux of kinetic energy at each level in the layer. The convecting layer is cooler on average compared with the initial temperature profile, and there is a net shift of mass towards the lower boundary. The implications of these results for the modern Laplacian theory of Solar system origin are briefly discussed. 相似文献
The results of 37 h of high-speed photometry of KPD 2109+4401 are described. At least five periodicities in the range 182–198 s are consistently present in the observations, with amplitudes in the range 1–6 mmag. Results of simultaneous multicolour high-speed photometry with the Stiening photometer are also presented; these data could in principle be used for mode identification of the periodicities. The results of a preliminary study suggest that the pulsations may all be ℓ = 1 and 2 modes. Properties of the star are compared with those of the other EC 14026 stars. 相似文献