A study of the dense Uniform Electron Gas with high orders of Coupled Cluster

We investigate the accuracies of different coupled cluster levels in a finite model solid, the 14 electron spin-non-polarised uniform electron gas. For densities between $\mathrm{r}_\mathrm{s}$ = 0.5 $\mathrm{a}_\mathrm{0}$ and $\mathrm{r}_\mathrm{s}$ = 5 $\mathrm{a}_\mathrm{0}$, we calculate ground state correlation energies with stochastic coupled cluster ranging from coupled cluster singles and doubles (CCSD) to coupled cluster including all excitations up to quintuples (CCSDTQ5). We find the need to add triple excitations for an accuracy of 0.01eV/electron beyond $\mathrm{r}_\mathrm{s}$ = 0.5 $\mathrm{a}_\mathrm{0}$. Quadruple excitations start being significant past $\mathrm{r}_\mathrm{s}$ = 3 $\mathrm{a}_\mathrm{0}$ . At $\mathrm{r}_\mathrm{s}$ = 5 $\mathrm{a}_\mathrm{0}$, CCSD gives a correlation energy with a 16% error and CCSDT is in error by 2% compared to the CCSDTQ5 result. CCSDTQ5 gives an energy in agreement with full configuration interaction quantum Monte Carlo results.Comment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in "Neufeld, V.A. and Thom, A.J.W., J. Chem. Phys. 147, 194105 (2017)" and may be found at https://aip.scitation.org/doi/abs/10.1063/1.5003794. The data and further information can be accessed at https://doi.org/10.17863/CAM.1433

The Measures and the loss - Case Study on non-tariff barriers related to veterinary export certificates in Dutch exports

Case study research into the mandatory veterinary requirements on Dutch exports of live animals and animal products provides empirical evidence on the trade effects of nontariff measures (NTMs). The paper discusses the analytical approach to assess how veterinary health attestation may create (temporary) obstacles for Dutch exports, what these obstacles are, and whether competing exporters in EU countries have encountered similar barriers. We have a dataset on 166 cases in 2004-06 where the process of issuing veterinary certificates for Dutch exports to non- EU destinations was disrupted. Products covered are animal-based products, live animals and feed. We use a sample of 30 cases that continued after 2006, the ‘longlasting problems’, and 39 cases that came up and got solved between 2004 and 2006, the temporary problems. The main challenge is to link the available record of recognition problems to the disruptions in exports. In order to assess trade disruptions, statistical tests of outliers and trend breaches are performed on detailed monthly trade data, and the issue of not-observed trade needs to be addressed. This raises the need to address disruption patterns around the imposition of measures in trade. The alternative patterns under examination are (i) measures that have an immediate trade impact, (ii) measures due to which trade gradually expands or reduces, and (iii) measures that divert trade to alternative export destinations. Finally, we want to examine whether the impact of veterinary health attestation on trade can be specified towards the type of trade barrier. For that, we suggest to introduce a distinction between three different types of barriers, based on whether obstacles relate to the non-conformity of products to import requirements or a failure in the conformity assessment or both.non-tariff measures, conformity assessment, animal products, International Relations/Trade, Livestock Production/Industries,

DSIF station schedules

System manages Deep Space Instrumentation Facilities /DSIF/ equipment construction and modification planning. Versatile program applies to such tasks as employee time and task schedules, pay schedules, operations schedules, and plant and equipment procurement, construction, modification or service

Magnetically controlled plasma accelerator Patent

Magnetically controlled plasma accelerator capable of ignition in low density gaseous environmen

Cattle Trade and the Risk of Importing Animal Diseases into the Netherlands

Projections of live cattle trade in the EU-25 assist to reduce the uncertainty on the risk of importing animal diseases in the Netherlands. The accession of 10 member states to the European Union has a potentially large impact on livestock trade in the EU as it liberalized in one stroke a trade that was administered by the Management Committee for Beef until May 1, 2004. The approach combines AG-Memod partial equilibrium with GTAP general equilibrium modelling in order to estimate the impact of quota liberalization. Quota removal will substantially alter the regional structure of livestock imports, as the share of new EU member states in the east triples to 25%. The risk outlook indicates a need for enhanced animal health services in the new member states.livestock, animal disease, trade, projections, quota, EU-enlargement, Risk and Uncertainty, F17, I18, Q17,

Granule Cell Dispersion in Human Temporal Lobe Epilepsy: Proteomics investigation of neurodevelopmental migratory pathways

Granule cell dispersion (GCD) is a common pathological feature observed in the hippocampus of patients with Mesial Temporal Lobe Epilepsy (MTLE). Pathomechanisms underlying GCD remain to be elucidated, but one hypothesis proposes aberrant reactivation of neurodevelopmental migratory pathways, possibly triggered by febrile seizures. This study aims to compare the proteomes of basal and dispersed granule cells in the hippocampus of eight MTLE patients with GCD to identify proteins that may mediate GCD in MTLE. Quantitative proteomics identified 1882 proteins, of which 29% were found in basal granule cells only, 17% in dispersed only and 54% in both samples. Bioinformatics analyses revealed upregulated proteins in dispersed samples were involved in developmental cellular migratory processes, including cytoskeletal remodelling, axon guidance and signalling by Ras homologous (Rho) family of GTPases (P<0.01). The expression of two Rho GTPases, RhoA and Rac1, was subsequently explored in immunohistochemical and in situ hybridisation studies involving eighteen MTLE cases with or without GCD, and three normal post mortem cases. In cases with GCD, most dispersed granule cells in the outer-granular and molecular layers have an elongated soma and bipolar processes, with intense RhoA immunolabelling at opposite poles of the cell soma, while most granule cells in the basal granule cell layer were devoid of RhoA. A higher density and percentage of cells expressing RhoA was observed in cases with GCD than without GCD (P<0.004). In GCD cases, the density and percentage of cells expressing RhoA was significantly higher in the inner molecular layer than granule cell layer (P<0.026), supporting proteomic findings. In situ hybridisation studies using probes against RHOA and RAC1 mRNAs revealed fine peri- and nuclear puncta in granule cells of all cases. The density of cells expressing RHOA mRNAs were significantly higher in the inner molecular layer of cases with GCD than without GCD(P=0.05). In summary, our study has found limited evidence for ongoing adult neurogenesis in the hippocampus of patients with MTLE, but evidence of differential dysmaturation between dispersed and basal granule cells has been demonstrated, and elevated expression of Rho GTPases in dispersed granule cells may contribute to the pathomechanisms underpinning GCD in MTLE

Diagrammatic Coupled Cluster Monte Carlo

We propose a modified coupled cluster Monte Carlo algorithm that stochastically samples connected terms within the truncated Baker--Campbell--Hausdorff expansion of the similarity transformed Hamiltonian by construction of coupled cluster diagrams on the fly. Our new approach -- diagCCMC -- allows propagation to be performed using only the connected components of the similarity-transformed Hamiltonian, greatly reducing the memory cost associated with the stochastic solution of the coupled cluster equations. We show that for perfectly local, noninteracting systems, diagCCMC is able to represent the coupled cluster wavefunction with a memory cost that scales linearly with system size. The favorable memory cost is observed with the only assumption of fixed stochastic granularity and is valid for arbitrary levels of coupled cluster theory. Significant reduction in memory cost is also shown to smoothly appear with dissociation of a finite chain of helium atoms. This approach is also shown not to break down in the presence of strong correlation through the example of a stretched nitrogen molecule. Our novel methodology moves the theoretical basis of coupled cluster Monte Carlo closer to deterministic approaches.Comment: 31 pages, 6 figure

A Compact High Velocity Cloud near the Magellanic Stream: Metallicity and Small-Scale Structure

The Magellanic Stream (MS) is a well-resolved gaseous tail originating from the Magellanic Clouds. Studies of its physical properties and chemical composition are needed to understand its role in Galactic evolution. We investigate the properties of a compact HVC (CHVC 224.0-83.4-197) lying close on the sky to the MS to determine whether it is physically connected to the Stream and to examine its internal structure. Our study is based on analysis of HST/COS spectra of three QSOs (Ton S210, B0120-28, and B0117-2837) all of which pass through this single cloud at small angular separation (\lessim 0.72{\deg}), allowing us to compare physical conditions on small spatial scales. No significant variation is detected in the ionization structure from one part of the cloud to the other. Using Cloudy photoionization models, toward Ton S210 we derive elemental abundances of [C/H] = -1.21 +/- 0.11, [Si/H] = -1.16 +/- 0.11, [Al/H] = -1.19 +/- 0.17 and [O/H] = -1.12 +/- 0.22, which agree within 0.09 dex. The CHVC abundances match the 0.1 solar abundances measured along the main body of the Stream. This suggests that the CHVC (and by extension the extended network of filaments to which it belongs) has an origin in the MS. It may represent a fragment that has been removed from the Stream as it interacts with the gaseous Galactic halo.Comment: ApJ, accepted, 13 pages, 12 figures, 4 table

Developments in Stochastic Coupled Cluster Theory: The initiator approximation and application to the Uniform Electron Gas

We describe further details of the Stochastic Coupled Cluster method and a diagnostic of such calculations, the shoulder height, akin to the plateau found in Full Configuration Interaction Quantum Monte Carlo. We describe an initiator modification to Stochastic Coupled Cluster Theory and show that initiator calculations can be extrapolated to the unbiased limit. We apply this method to the 3D 14-electron uniform electron gas and present complete basis set limit values of the CCSD and previously unattainable CCSDT correlation energies for up to rs = 2, showing a requirement to include triple excitations to accurately calculate energies at high densities.Comment: 14 pages, 12 figure

Product differentiation under the WTO; An analysis of labelling and tariff or tax measures concerning farm animal welfare

This report examines the possibility of giving preferential treatment to imports of meat products that meet improved standards in terms of animal welfare in production. Three specific forms of preferential treatment are considered here as possible measures for increasing levels of animal welfare in meat production in the EU and its exporting partners: labelling of products (either voluntary or compulsory), differentiated import tariffs and differentiated consumer taxes. The likely admissibility of such measures under WTO rules is assessed by means of an analysis of previous decisions by WTO dispute settlement panels. It is concluded that all of the measures analysed have a possibility of being upheld, based on a defence relying on Article XX of the GATT and perhaps also the TBT Agreement. While the incentives offered by labelling could be reinforced with differentiated tariffs or taxes, these financial instruments involve various additional complications. They could best be considered after the possibilities of regulated labelling schemes have been exhausted.International Relations/Trade,