A sensitivity analysis of the prediction of the nitrogen fertilizer requirement of cauliflower crops using the HRI WELL_N computer model

HRI WELL_N is an easy to use computer model, which has been used by farmers and growers since 1994 to predict crop nitrogen (N) requirements for a wide range of agricultural and horticultural crops. A sensitivity analysis was carried out to investigate the model predictions of the N fertilizer requirement of cauliflower crops, and, at that rate, the yield achieved, yield response to the fertilizer applied, N uptake, NO3-N leaching below 30 and 90 cm and mineral N at harvest. The sensitivity to four input factors – soil mineral N before planting, mineralization rate of soil organic matter, expected yield and duration of growth – was assessed. Values of these were chosen to cover ranges between 40% and 160% of values typical for field crops of cauliflowers grown in East Anglia. The assessments were made for three soils – sand, sandy loam and silt – and three rainfall scenarios – an average year and years with 144% or 56% of average rainfall during the growing season. The sensitivity of each output variable to each of the input factors (and interactions between them) was assessed using a unique ‘sequential' analysis of variance approach developed as part of this research project. The most significant factors affecting N fertilizer requirement across all soil types/rainfall amounts were soil mineral N before planting and expected yield. N requirement increased with increasing yield expectation, and decreased with increasing amounts of soil mineral N before planting. The responses to soil mineral N were much greater when higher yields were expected. Retention of N in the rooting zone was predicted to be poor on light soils in the wettest conditions suggesting that to maximize N use, plants needed to grow rapidly and have reasonable yield potential. Assessment of the potential impacts of errors in the values of the input factors indicated that poor estimation of, in particular, yield expectation and soil mineral N before planting could lead to either yield loss or an increased level of potentially leachable soil mineral N at harvest. The research demonstrates the benefits of using computer simulation models to quantify the main factors for which information is needed in order to provide robust N fertilizer recommendations

Optimal Placement of Intrusion Detection Systems to Identify Multi-Stage Attacks in Software Defined Networks

A major threat to network security is the multi-stage attack, where an attacker compromises an outer edge server from which he penetrates an inner server, and so on, until he gains access to protected information deep in the network. Intrusion detection systems (IDS) can detect such attacks, but limited resources constrain the number of IDS deployed. Software defined networking (SDN) provides network flexibility, and combined with network function virtualization (NFV), it enables IDS placement optimizations that can relieve cost constraint pressures. In this work, we develop a novel algorithm for placing IDS to maximize network protection benefits and minimize costs. The benefit of an IDS configuration is given by the probability of reducing an attacker’s chance of success, and the corresponding cost includes IDS installation and operational costs. We find the configuration which yields the highest benefit given a cost constraint by using the genetic algorithm for optimization, and we compare its results to exhaustive techniques. For networks with more than 5 servers, the algorithm consistently maintains over 85% of the maximum benefit with its placement of IDS, while keeping costs as low as 30% of the naive complete-coverage cost. The genetic algorithm error is less than 5% when compared to exhaustive techniques; and for networks larger than 10 servers, the genetic algorithm runtime is less than a third of the exhaustive search runtime. Using our solution, network administrators can reduce the costs of protecting their systems from multi-stage attacks

Electronic properties of H on vicinal Pt surfaces: A first-principles study

In this work, we use the first-principle density-functional approach to study the electronic structure of a H atom adsorbed on the ideal Pt(111) and vicinal Pt(211) and Pt(331) surfaces. Full three-dimensional potential-energy surfaces (3D PES's) as well as local electronic density of states on various adsorption sites are obtained. The results show that the steps modify the PES considerably. The effect is nonlocal and extends into the region of the (111) terraces. We also find that different type of steps have different kind of influence on the PES when compared to the one of the ideal Pt(111) surface. The full 3D PES's calculated in this work provide a starting point for the theoretical study of vibrational and diffusive dynamics of H adatoms adsorbed on these vicinal surfaces.Comment: 8 pages with 5 figures and 3 tables. In version 2, there have been made some minor changes and a bigger one in Section III.A.1 where the results of the test calculations dealt with the accuracy of the present results have been adde

The Adoption of the Euro, Choice of Currency Regime and Integration of Payment Systems

1) The Adoption of the Euro by New Member States: Challenges and Vulnerabilities by Michael C. Bonello 2) The Economics of Offshore Financial Services and the Choice of Tax, Currency, and Exchange-Rate Regimes by George M. von Furstenberg 3) Promoting Integration of European Retail Payment Systems: Role of Competition, Cooperation and Regulation (Kari Kemppainen and Sinikka Salo

Facing the future : scanning, synthesizing and sense-making in horizon scanning

Erworben im Rahmen der Schweizer Nationallizenen (http://www.nationallizenz.ch)In this paper, we discuss key issues in harnessing horizon scanning to shape systemic policies, particularly in the light of the foresight exercise ‘Facing the future: Time for the EU to meet global challenges’ which was carried out for the Bureau of European Policy Advisors. This exercise illustrates how horizon scanning can enable collective sense-making processes which assist in the identification of emerging signals and policy issues; the synthesis of such issues into encompassing clusters; and the interpretation of resulting clusters as an important step towards the coordinated development of joint policy measures. In order to achieve such objectives, horizon scanning can benefit from methods of multi-criteria decision-making and network analysis for prioritizing, clustering and combining issues. Furthermore, these methods provide support for traceability, which in turn contributes to the enhanced transparency and legitimacy of foresight

Spatial Structure and Coherent Motion in Dense Planetary Rings Induced by Self-Gravitational Instability

We investigate the formation of spatial structure in dense, self-gravitating particle systems such as Saturn's B-ring through local $N$-body simulations to clarify the intrinsic physics based on individual particle motion. In such a system, Salo (1995) showed that the formation of spatial structure such as wake-like structure and particle grouping (clump) arises spontaneously due to gravitational instability and the radial velocity dispersion increases as the formation of the wake structure. However, intrinsic physics of the phenomena has not been clarified. We performed local $N$-body simulations including mutual gravitational forces between ring particles as well as direct (inelastic) collisions with identical (up to $N\sim40000$) particles. In the wake structure particles no longer move randomly but coherently. We found that particle motion was similar to Keplerian motion even in the wake structure and that the coherent motion was produced since the particles in a clump had similar eccentricity and longitude of perihelion. This coherent motion causes the increase and oscillation in the radial velocity dispersion. The mean velocity dispersion is rather larger in a more dissipative case with a smaller restitution coefficient and/or a larger surface density since the coherence is stronger in the more dissipative case. Our simulations showed that the wavelength of the wake structure was approximately given by the longest wavelength \hs{\lambda}{cr} = 4\pi^2 G\Sigma/\kappa^2 in the linear theory of axisymmetric gravitational instability in a thin disk, where $G$, $\Sigma$, and $\kappa$ are the gravitational constant, surface density, and a epicyclic frequency.Comment: Accepted by Earth, Planets, and Space. 39 pages, 20 figures. PostScript files also available from http://www.geo.titech.ac.jp/nakazawalab/hdaisaka/works

Impact of Astroprincin (FAM171A1) Expression in Oral Tongue Cancer

Astroprincin (APCN, FAM171A1) is a recently characterized transmembrane glycoprotein that is abundant in brain astrocytes and is overexpressed in some tumors. However, the expression and role of APCN is unknown in oral tongue squamous cell carcinoma (OTSCC). Aim of this study was to investigate the expression of APCN in OTSCC tissue samples and to analyze possible association of APCN with clinicopathological features and survival rates. This study included 76 patients treated for OTSCC. Expression of APCN in OTSCC tissue sections was examined by immunohistochemistry with a rabbit polyclonal antibody (MAP346) against APCN. All tumors were scored for intensity and percentage of APCN staining at the superficial, middle, and invasive front areas. High expression of APCN was significantly associated with increased tumor size (P = 0.013) and with OTSCC recurrence (P = 0.026). In this pilot study, we observed that the amount of APCN is associated with the size and recurrence of OTSCC. This finding suggests a role of APCN during OTSCC progression.Peer reviewe

Searching for transition paths in multidimensional space with a fixed repulsive bias potential

An efficient method for searching for transition paths in a multidimensional configuration space is proposed. It is based on using a fixed, locally repulsive bias potential, which forces the system to move from a given initial state to a different final state. This simple method is very effective in determining nearby configurations and possible transition paths for many-particle systems. Once the approximate transition paths are known, the corresponding activation energies can be computed using, e.g., the nudged elastic band method. The usefulness of the present method is demonstrated for both classical and quantum-mechanical systems.Peer reviewe

Minimum energy paths for dislocation nucleation in strained epitaxial layers

We study numerically the minimum energy path and energy barriers for dislocation nucleation in a two-dimensional atomistic model of strained epitaxial layers on a substrate with lattice misfit. Stress relaxation processes from coherent to incoherent states for different transition paths are determined using saddle point search based on a combination of repulsive potential minimization and the Nudged Elastic Band method. The minimum energy barrier leading to a final state with a single misfit dislocation nucleation is determined. A strong tensile-compressive asymmetry is observed. This asymmetry can be understood in terms of the qualitatively different transition paths for the tensile and compressive strains.Peer reviewe