The perturbation bound of the extended vertical linear complementarity problem

In this paper, we discuss the perturbation analysis of the extended vertical linear complementarity problem (EVLCP). Under the assumption of the row $\mathcal{W}$-property, several absolute and relative perturbation bounds of EVLCP are given, which can be reduced to some existing results. Some numerical examples are given to show the proposed bounds

Estimating the Spatial Distribution of Groundwater Demand In the Texas High Plains

Developing groundwater management plans requires a good understanding of the interdependence of groundwater hydrology and producer water use behavior. While state-of-the-art groundwater models require water demand data at highly disaggregated levels, the lack of producer water use data has held up the progress to meet that need. This paper proposes an econometric framework that links county-level crop acreage data to well-level hydrologic data to produce heterogeneous patterns of crop choice and irrigation practices within a county. Together with agronomic data on irrigation water requirements of various crops and irrigation practices, this model permits estimation of the water demand distribution within a county. We apply this model to a panel of 16 counties in the Southern Texas High Plains from 1972 to 2000. The results obtained not only are consistent with those from the traditional multinomial logit land use model, but also indicate the presence of large intra- and inter-county heterogeneity in producer water use behavior.Discrete Choice Model, Random-coefficients Discrete Choice Model, Crop Choice, BLP, Groundwater, Texas High Plains, Ogallala Aquifer, Crop Production/Industries, Resource /Energy Economics and Policy,

Neutron powder diffraction study on the iron-based nitride superconductor ThFeAsN

We report neutron diffraction and transport results on the newly discovered superconducting nitride ThFeAsN with $T_c=$ 30 K. No magnetic transition, but a weak structural distortion around 160 K, is observed cooling from 300 K to 6 K. Analysis on the resistivity, Hall transport and crystal structure suggests this material behaves as an electron optimally doped pnictide superconductors due to extra electrons from nitrogen deficiency or oxygen occupancy at the nitrogen site, which together with the low arsenic height may enhance the electron itinerancy and reduce the electron correlations, thus suppress the static magnetic order.Comment: 4 pages, 4 figures, Accepted by EP

Dissecting the Genetic Architecture of Complex Traits: Hot Spots and Vascular Collaterals

Collateral arteries are endogenous “bypass vessels” that minimize tissue injury during arterial obstruction. Recent studies from our laboratory demonstrate that wide variation exists among individuals in the extent (number and diameter) of native (pre-existing) collaterals in healthy tissue and their outward remodeling (increase in anatomic diameter) in obstructive disease. Evidence suggests this variation contributes importantly to the wide variation in thromboembolic stroke, ischemic heart disease and peripheral arterial disease in humans. We hypothesized that genetic components contribute significantly to this variation. We tested this hypothesis in 243 C57BL/6 X BALB/c (CXB) F2 mice, wherein number and diameter of native cerebral collaterals and collateral remodeling after middle cerebral artery occlusion (MCAO) were measured. Linkage analysis identified a major QTL on chromosome 7 (Canq1) responsible for more than 30% of the variation in collateral extent. Three additional QTL were obtained for collateral number. Analysis of chromosome substitution and CXB recombinant inbred strains confirmed the dominant role of the Canq1 locus. We also identified a QTL on chromosome 11 linked to variation in collateral remodeling. Efficient mix model association mapping (EMMA) of collateral number among 15 inbred strains delineated 172k (p=0.00002) and 290k (p=0.0004) base-pair regions containing 2 and 7 candidate genes, respectively, within Canq1. Analysis of six additional inbred strains, chosen according to their haplotype within the 172 kb EMMA region, strengthened and narrowed the locus from 172 kb interval to 2 kb. In candidate gene analyses, we found that collateral extent, infarct volume after MCAO, bleeding and re-bleeding times did not differ between Itgal-/,-IL4-/- or IL4-receptor-α-/- and wildtype mice. mRNA expression of 120 genes within the 95% confidence interval of Canq1, measured in the pial vasculature of C57BL/6 and BALB/c at embryonic day-14.5, -16.5 and -18.5 when the collateral circulation forms, identified 19 differentially expressed genes. These results demonstrate that native collateral extent and collateral remodeling are heritable complex traits, with a highly significant QTL on chromosome 7 governing the majority of the variation in these traits. Furthermore, my work prioritizes a set of genes for future analysis as candidates underlying the process of collateral formation and its variation among individuals

Plastome organization and evolution of chloroplast genes in Cardamine species adapted to contrasting habitats

© 2015 Hu et al.; licensee BioMed Central. Background: Plastid genomes, also known as plastomes, are shaped by the selective forces acting on the fundamental cellular functions they code for and thus they are expected to preserve signatures of the adaptive path undertaken by different plant species during evolution. To identify molecular signatures of positive selection associated to adaptation to contrasting ecological niches, we sequenced with Solexa technology the plastomes of two congeneric Brassicaceae species with different habitat preference, Cardamine resedifolia and Cardamine impatiens. Results: Following in-depth characterization of plastome organization, repeat patterns and gene space, the comparison of the newly sequenced plastomes between each other and with 15 fully sequenced Brassicaceae plastomes publically available in GenBank uncovered dynamic variation of the IR boundaries in the Cardamine lineage. We further detected signatures of positive selection in ten of the 75 protein-coding genes of the examined plastomes, identifying a range of chloroplast functions putatively involved in adaptive processes within the family. For instance, the three residues found to be under positive selection in RUBISCO could possibly be involved in the modulation of RUBISCO aggregation/activation and enzymatic specificty in Brassicaceae. In addition, our results points to differential evolutionary rates in Cardamine plastomes. Conclusions: Overall our results support the existence of wider signatures of positive selection in the plastome of C. resedifolia, possibly as a consequence of adaptation to high altitude environments. We further provide a first characterization of the selective patterns shaping the Brassicaceae plastomes, which could help elucidate the driving forces underlying adaptation and evolution in this important plant family