Electronic structure investigation of the cubic inverse perovskite Sc3AlN

The electronic structure and chemical bonding of the recently discovered inverse perovskite Sc3AlN, in comparison to ScN and Sc metal have been investigated by bulk-sensitive soft x-ray emission spectroscopy. The measured Sc L, N K, Al L1, and Al L2,3 emission spectra are compared with calculated spectra using first principle density-functional theory including dipole transition matrix elements. The main Sc 3d - N 2p and Sc 3d - Al 3p chemical bond regions are identified at -4 eV and -1.4 eV below the Fermi level, respectively. A strongly modified spectral shape of 3s states in the Al L2,3 emission from Sc3AlN in comparison to pure Al metal is found, which reflects the Sc 3d - Al 3p hybridization observed in the Al L1 emission. The differences between the electronic structure of Sc3AlN, ScN, and Sc metal are discussed in relation to the change of the conductivity and elastic properties.Comment: 11 pages, 5 picture

The GAINS Model for Greenhouse Gases - Version 1.0: Methane (CH4)

Many of the traditional air pollutants and greenhouse gases have common sources, offering a cost-effective potential for simultaneous improvements of traditional air pollution problems and climate change. A methodology has been developed to extend the RAINS integrated assessment model to explore synergies and trade-offs between the control of greenhouse gases and air pollution. With this extension, the GAINS (GHG-Air pollution INteraction and Synergies) model will allow the assessment of emission control costs for the six greenhouse gases covered under the Kyoto Protocol (CO2, CH4, N2O and the three F-gases) together with the emissions of air pollutants SO2, NOx, VOC, NH3 and PM. This report describes the first implementation (Version 1.0) of the model extension model to incorporate CH4 emissions. GAINS Version 1.0 assesses the options for reducing N2O emissions from the various source categories. It quantifies for 43 countries/regions in Europe country-specific application potentials of the various options in the different sectors of the economy, and estimates the societal resource costs of these measures. Mitigation potentials are estimated in relation to an exogenous baseline projection that is considered to reflect current planning. The report identifies 28 control measures, ranging from animal feed changes over waste management options to various approaches for gas recovery and utilization. For each of these options, the report examines country-specific applicability and removal efficiency and determines the costs. As a result, CH4 emissions in Europe are estimated for the year 1990 at 63,600 kt CH4. Assuming the penetration of emission controls as laid down in the current legislation, emissions would decline up to 2020 by 12,600 kt CH4 per year. Full application of the presently available emission control measures could achieve an additional decline in European CH4 emissions by 24,000 kt per year. Seventy percent of this potential could be attained at a cost of less than two billion Euro/year or Euro/ton CO2- equivalent, while the further 7,000 kt CH4/year would require costs of 12 billion Euro/year

The GAINS Model for Greenhouse Gases: Emissions, Control Potentials and Control Costs for Methane

This report estimates current and future emissions of methane in 42 regions in Europe, assesses the potential for reducing emissions and quantifies the costs of the available emission control measures. The report identifies 28 control measures, ranging from animal feed changes over waste management options to various approaches for gas recovery and utilization. For each of these options, the report examines country-specific applicability and removal efficiency and determines the costs. As a result, methane emissions in Europe are estimated for the year 1990 at 64,200 kt CH4. Assuming the penetration of emission controls as laid down in the current legislation, emissions would decline up to 2020 by 11,700 kt CH4 per year. Full application of the presently available emission control measures could achieve an additional decline in European methane emissions by 24,000 kt per year. 75 percent of this potential could be attained at a cost of less than two billion Euros/year or 50 Euros/t CO2-equivalent, while the further 5,000 kt CH4/year would require costs of 12 billion Euros/year

Zero-inflated hierarchical models for faecal egg counts to assess anthelmintic efficacy

The prevalence of anthelmintic resistance has increased in recent years, as a result of the extensive use of anthelmintic drugs to reduce the infection of parasitic worms in livestock. In order to detect the resistance, the number of parasite eggs in animal faeces is counted. Typically a subsample of the diluted faeces is examined, and the mean egg counts from both untreated and treated animals are compared. However, the conventional method ignores the variabilities introduced by the counting process and by different infection levels across animals. In addition, there can be extra zero counts, which arise as a result of the unexposed animals in an infected population or animals. In this paper, we propose the zero-inflated Bayesian hierarchical models to estimate the reduction in faecal egg counts. The simulation study compares the Bayesian models with the conventional faecal egg count reduction test and other methods such as bootstrap and quasi-Poisson regression. The results show the Bayesian models are more robust and they perform well in terms of both the bias and the coverage. We further illustrate the advantages of our proposed model using a case study about the anthelmintic resistance in Swedish sheep flocks

Genome-wide analysis of the response to ivermectin treatment by a Swedish field population of Haemonchus contortus

Haemonchus contortus is a pathogenic gastrointestinal nematode of small ruminants and, in part due to its capacity to develop resistance to drugs, contributes to significant losses in the animal production sector worldwide. Despite decades of research, comparatively little is known about the specific mechanism(s) driving resistance to drugs such as ivermectin in this species. Here we describe a genome-wide approach to detect evidence of selection by ivermectin treatment in a field population of H. contortus from Sweden, using parasites sampled from the same animals before and seven days after ivermectin exposure followed by whole-genome sequencing. Despite an 89% reduction in parasites recovered after treatment measured by the fecal egg count reduction test, the surviving population was highly genetically similar to the population before treatment, suggesting that resistance has likely evolved over time and that resistance alleles are present on diverse haplotypes. Pairwise gene and SNP frequency comparisons indicated the highest degree of differentiation was found at the terminal end of chromosome 4, whereas the most striking difference in nucleotide diversity was observed in a region on chromosome 5 previously reported to harbor a major quantitative trait locus involved in ivermectin resistance. These data provide novel insight into the genome-wide effect of ivermectin selection in a field population as well as confirm the importance of the previously established quantitative trait locus in the development of resistance to ivermectin

The Lanczos potential for Weyl-candidate tensors exists only in four dimensions

We prove that a Lanczos potential L_abc for the Weyl candidate tensor W_abcd does not generally exist for dimensions higher than four. The technique is simply to assume the existence of such a potential in dimension n, and then check the integrability conditions for the assumed system of differential equations; if the integrability conditions yield another non-trivial differential system for L_abc and W_abcd, then this system's integrability conditions should be checked; and so on. When we find a non-trivial condition involving only W_abcd and its derivatives, then clearly Weyl candidate tensors failing to satisfy that condition cannot be written in terms of a Lanczos potential L_abc.Comment: 11 pages, LaTeX, Heavily revised April 200

Risk factors for severe postoperative complications in dogs with cranial cruciate ligament disease-A survival analysis

Objective: To analyze the effect of surgical technique and other risk factors on severe postoperative complications in dogs with cranial cruciate ligament disease (CCLD). Materials and Methods: A cohort study of 255 dogs (287 stifles) surgically treated for CCLD at two veterinary university hospitals (2011 & ndash;2016) was performed. The electronic medical records were reviewed and dog owners and referring veterinarians contacted for additional information. The complications were classified as minor, major and catastrophic, where major and catastrophic were considered severe. A multivariable Cox proportional hazards model was applied to assess risk factors for severe postoperative complications.Results: Three surgical techniques were used; lateral fabellotibial suture (LFS, 141 stifles), tibial plateau leveling osteotomy (TPLO, 77 stifles) and tibial tuberosity advancement (TTA, 69 stifles). The most common severe postoperative complications were surgical site infections or complications related to the surgical implant. Severe postoperative complications occurred in 31 % of the stifles treated with TPLO, 22 % of the stifles treated with LFS and 25 % of the stifles treated with TTA. The multivariable Cox proportional hazards model identified surgical technique (p = 0.0258) as a risk factor for severe postoperative complications; TPLO had a significantly lower hazard than LFS (hazard ratio (HR) = 0.37, p = 0.007) when controlling for body weight and age, which also were identified as risk factors (HR = 1.05, p < 0.001 and HR = 0.91, p = 0.047, respectively).Conclusion and Clinical relevance: Although TPLO procedures had the highest occurrence of severe postoperative complications, the hazard was lower than for LFS after adjusting for body weight and age. This implies that it is important to consider potential effect-modifiers when comparing postoperative complications after CCLD surgery