Trend reversal of nitrate in Danish groundwater--a reflection of agricultural practices and nitrogen surpluses since 1950

This paper assesses the long-term development in the oxic groundwater nitrate concentration and nitrogen (N) loss due to intensive farming in Denmark. First, up to 20-year time-series from the national groundwater monitoring network enable a statistically systematic analysis of distribution, trends, and trend reversals in the groundwater nitrate concentration. Second, knowledge about the N surplus in Danish agriculture since 1950 is used as an indicator of the potential loss of N. Third, groundwater recharge CFC (chlorofluorocarbon) age determination allows linking of the first two data sets. The development in the nitrate concentration of oxic groundwater clearly mirrors the development in the national agricultural N surplus, and a corresponding trend reversal is found in groundwater. Regulation and technical improvements in the intensive farming in Denmark have succeeded in decreasing the N surplus by 40% since the mid 1980s, while at the same time maintaining crop yields and increasing the animal production of especially pigs. Trend analyses prove that the youngest (0-15 years old) oxic groundwater shows more pronounced significant downward nitrate trends (44%) than the oldest (25-50 years old) oxic groundwater (9%). This amounts to clear evidence of the effect of reduced nitrate leaching on groundwater nitrate concentrations in Denmark.     

Optimal joint utility based load balancing algorithm for heterogeneous wireless networks

The rapid development of mobile broadband services with continuously increasing traffic volumes has resulted in a number of challenges, including ubiquitous network coverage, high bandwidth, and reliable services for reasonable price, etc. To address these challenges, evolved packet system (EPS) is proposed as the evolution of the packet core network. While resource management and load balancing issues in EPS are discussed in 3GPP standardization, relatively few research works consider mechanism design for load information monitoring and evaluation. Furthermore, even though some load balancing algorithms have been proposed for integrated networks, the load balancing scheme design which achieves the optimization of joint system performance has not been extensively studied. In this paper, an inter-access system anchor based load balancing mechanism is introduced which performs load monitoring and evaluation for access gateways and networks, and an optimal load balancing algorithm is proposed for heterogeneous integrated networks. To characterize the performance of integrated networks, the concept of utility function is introduced and the comprehensive performance of integrated networks which support both single type service and multimedia service is modeled mathematically. Applying vertical handoff as an efficient mechanism for achieving load balancing, the optimal number of handoff users is obtained through solving the optimization problem. Numerical results demonstrate that load balancing between access networks can be achieved, and the optimal number of handoff users corresponding to the maximal joint network utility can be obtained.     

Trace ratio criterion based generalized discriminative learning for semi-supervised dimensionality reduction

Dealing with high-dimensional data has always been a major problem in many pattern recognition and machine learning applications. Trace ratio criterion is a criterion that can be applicable to many dimensionality reduction methods as it directly reflects Euclidean distance between data points of within or between classes. In this paper, we analyze the trace ratio problem and propose a new efficient algorithm to find the optimal solution. Based on the proposed algorithm, we are able to derive an orthogonal constrained semi-supervised learning framework. The new algorithm incorporates unlabeled data into training procedure so that it is able to preserve the discriminative structure as well as geometrical structure embedded in the original dataset. Under such a framework, many existing semi-supervised dimensionality reduction methods such as SDA, Lap-LDA, SSDR, SSMMC, can be improved using our proposed framework, which can also be used to formulate a corresponding kernel framework for handling nonlinear problems. Theoretical analysis indicates that there are certain relationships between linear and nonlinear methods. Finally, extensive simulations on synthetic dataset and real world dataset are presented to show the effectiveness of our algorithms. The results demonstrate that our proposed algorithm can achieve great superiority to other state-of-art algorithms.     

Influence of Loss Model on Design Discharge of Homogeneous Plane

By applying the kinematic wave method to a homogeneous, rectangular overland plane, the influence of the constant and proportional-loss models on the design discharge are examined. The examination shows that with the use of the proportional-loss model, there is no partial-area effect and the design discharge is governed by the full-area contribution. On the other hand, with the use of the constant-loss model, there is no partial-area effect if the loss rate is small. For larger loss rates, there is a partial-area effect; and for this case, the design is complicated, since there is a need to search for the critical storm that governs the partial-area effect. The characteristic of the critical storm is that its rate of decrease in rainfall intensity with duration equals the corresponding rate of increase in the contributing area. The preceding findings are consistent with the design concept in the rational method that uses the proportional-loss model, and the results from earlier studies that used the constant-loss model.     

Protein-protein and protein-DNA interactions in the type I restriction endonuclease R.EcoR124I

The type I restriction-modification system EcoR124I recognizes and binds to the split DNA recognition sequence 5'-GAAN(6)RTCG-3'. The methyltransferase, consisting of HsdM and HsdS subunits with the composition M2S, can interact with one or more subunits of the HsdR subunit to form the endonuclease. The interaction of the methyltransferase with HsdR has been investigated by surface plasmon resonance, showing that there are two non-equivalent binding sites for HsdR which differ in binding affinity by at least two orders of magnitude. DNA footprinting experiments using Exonuclease III suggest that the addition of HsdR to the methyltransferase (at a stoichiometry of either 1:1 or 2:1) increases the stability of the resulting DNA-protein complex but does not increase the size of the footprint. More extensive in situ footprinting experiments using copper-phenanthroline on the DNA-protein complexes formed by M2S, R1M2S and R2M2S also show no difference in the detailed cleavage pattern, with approximately 18 nucleotides protected on both strands in each complex. Thus the HsdR subunit(s) of the endonuclease stabilise the interaction of the M2S complex with DNA, but do not directly contribute to DNA binding. In addition, the thymidine nucleotide in the tetranucleotide recognition sequence GTCG is hyper-reactive to cleavage in each case, suggesting that the DNA structure in this region is altered in these complexes.     

Proton magnetic resonance imaging of lipid in pecan embryos

Magnetic resonance images of plant tissues typically are manifestations of water protons in tissues. Within oilseeds, however, lipids contain a major portion of the mobile protons, which should enable specific imaging of lipids. In this study, experiments were done to demonstrate spin-echo imaging (SEI) and chemical-shift imaging (CSI) of lipid within nonimbibed and imbibed embryos of pecan (Carya illinoensis), a high-lipid seed. Magnetic resonance spectra of airdry embryos contained a single major peak for lipid, whereas those of imbibed embryos contained separate peaks for water and lipid. This separation of spectral peaks enabled CSI of distributions of either lipids or water in imbibed embryos. A longer spin-spin relaxation time of lipid protons than of water protons in imbibed embryos allowed selective SEI of lipids in those embryos. SEI of normal, dry embryos revealed fairly uniform distribution of lipids across tissues. Similar images of embryos damaged by the fungusPhoma exocarpina or the insectZerara viridula were less intense than those of a normal embryo, reflecting the lower oil contents of the damaged embryos. Magnetic resonance imaging should provide a useful technology for studying lipid distribution and metabolism within oil seeds.     

The Dynamics of Indonesia's Urbanisation, 1980-2006

This study examines continuity and change in patterns of Indonesia's urbanisation during the boom economy until the decentralisation era, using data mainly from the National Population Census 1980-2000 and from the Village Potential (PODES) 2006. Urbanisation in Indonesia is still characterised by a heavy concentration of the urban population in a few large cities, notably the Jakarta Metropolitan Area (JMA), which might reflect an integration of Jakarta into the global economy. It might also reflect an interurban disparity, between large and smaller cities. The population on the fringes of large cities is growing rapidly, while in the inner cities it is increasing at a very low rate of growth. Urban spatial development in Java is shaping belts, which connect many of the large cities. The intermediate cities and small towns on the outer islands have a relatively higher population growth rate compared with those in Java, which might suggest that those towns and cities are playing a more significant role in regional development.     

Telephone administration of the SF-36 health survey: validation studies and population norms for adults in Queensland

The Rand Corporation medical outcomes short-form 36 health survey (SF-36) is a multidimensional measure of self-perceived general health status, which has been validated in adult populations in the United States and Great Britain, and, more recently, in an Australian population. The SF-36 is increasingly being used in health outcomes research internationally, mainly as a self-administered tool, and clearly has potential for use in Australia. This study aimed to assess the acceptability, reliability and validity of telephone administration of the instrument in the Queensland adult population, and to provide reliable population norms. We report the results of a telephone survey in which we interviewed 12,793 adults. It was the first large-scale, statewide application of the SF-36 in Australia. A response rate of 82 per cent was achieved, and the SF-36 satisfied psychometric criteria for reliability and construct validity. Population norms broken down by age and sex are provided. They will be important for the interpretation of future studies using the SF-36 in particular population or patient groups.