A class of Baker-Akhiezer arrangements

We study a class of arrangements of lines with multiplicities on the plane which admit the Chalykh–Veselov Baker–Akhiezer function. These arrangements are obtained by adding multiplicity one lines in an invariant way to any dihedral arrangement with invariant multiplicities. We describe all the Baker–Akhiezer arrangements when at most one line has multiplicity higher than 1. We study associated algebras of quasi-invariants which are isomorphic to the commutative algebras of quantum integrals for the generalized Calogero–Moser operators. We compute the Hilbert series of these algebras and we conclude that the algebras are Gorenstein. We also show that there are no other arrangements with Gorenstein algebras of quasi-invariants when at most one line has multiplicity bigger than 1

Comparative anatomical studies of responses of some roadside plants to highway automobile exhausts

Urena lobata and Hyptis suaveolens growing along busy roadsides in Lafia, Nigeria were carefully sampled. This was with a view to investigate the effect of continuous impact of automobile exhausts on internal structures of the plants. Three major highways were chosen for study in Lafia. Plant samples were systematically collected in replicates from 0 m, 10 m and 20 m away from defined points of the roadsides. Leaf and stem anatomical sections were prepared for microscopic examinations following established procedures. The plants were observed to have more stomata and smaller area of guard cells at 0 m than those away from the roadsides. For H. suaveolens, the thickness of epidermis, thickness of vascular bundles, length and number of trichomes at 0 m are higher than those at 10 m and 20 m. The reverse was observed for U. lobata. However, U. lobata showed high number of parenchyma cells closer to the roadsides than those father away. Consequently, H. suaveolens seemed to have ability to withstand and thrive well in areas of heavy air pollution. These anatomical changes were described to be distinct with regards to individual species and could have been as a result of cumulative effects of air pollutants.Keywords: Air pollutants, Anatomy, Hyptis suaveolens, Lafia, Urena lobat

Method of efficiently predicting the conducted emissions of multiple VSCs

Various types of power converters including Voltage Source Converters (VSCs) have been known to produce conducted emissions. The net effect of simultaneously operating multiple VSCs is non-linear and this makes the prediction of the emission level more difficult. This paper presents an efficient method that can be used to predict conducted emissions of multiple VSCs in the presence of various uncertainties. It utilizes the Univariate Dimension Reduction (UDR) and the Bivariate Dimension Reduction (BDR) technique to predict the conducted emission level of multiple VSCs

Phyto-extraction ability of Digitaria exilis (Fonio) to heavy metals

Among the different contaminants in the environment, heavy metals are unique due to the fact that they cannot be broken down to non-toxic forms. The research was conducted to determine the remediation potential of Digitaria exilis and to identify the varieties that can tolerate heavy metals contamination. Soil was collected in an Automobile mechanic workshop, Government Reserved Area (GRA) Ado-Ekiti. Five kilograms (5 kg) of soils collected was air dried, sieved and filled into plastic buckets. The experiment was a completely randomized designed with three replicates. Three different accessions of Digitaria exilis namely; Jakah D Iburua (JAK), Dinat D Iburua (DID) and Jiw D Iburau (JIW) were planted. Soils were watered till field moisture capacity. Plant height was determined every two weeks after planting. Soil analysis was carried out to determine the physical and chemical properties before and after the experiment. Heavy metals including Cd, Fe, Zn, Pb, As and Cu were determined in the plant roots and shoots using Atomic Absorption Spectrophotometer (AAS). Accession JAK Bio-accumulated heavy-metals in their root than shoot, consequently, significant high plant height was recorded. However, shoot of accession JAK accumulated 22 % Pb, 46.78% Cu and 37.5% Cd and 20.3% Zn than others whereas accession DID accumulated As than accession JAK. Therefore, accession JAK demonstrated highest phyto-extraction of heavy-metals potentials at the root. Variety JIW has the lowest plant height, root and shoots heavy metals accumulation. Although heavy metals contaminated soil affected the growth of D. exilis, nevertheless accession JAK has the highest productivity under this condition and can be further recommended in phyto-extraction of heavy-metals in polluted sites.Keywords: Phyto-extraction, Digitaria exilis and Heavy-metal

Gravitationally dresed RG flows and zig-zag invariant strings

We propose a world-sheet realization of the zigzag-invariant bosonic and fermionic strings as a perturbed Wess-Zumino-Novikov-Witten model at large negative level $k$ on a group manifold $G$ coupled to 2D gravity. In the large $k$ limit the zigzag symmetry can be obtained as a result of a self-consistent solution of the gravitationally dressed RG equation. The only solution found for simple group is $G=SL(2)$. More general target-space geometries can be obtained via tensoring of various cosets based on SL(2). In the supersymmetric case the zigzag symmetry fixes the maximal target-space dimension of the confining fermionic string to be seven.Comment: 16 pages, corrected typos, version to be published in Phys.Lett.

Effect of exogenous melatonin on antioxidant defense system and osmo-regulatory solutes of drought-stressed Morinda citrifolia

Morinda citrifolia is a small tropical tree that contains active natural metabolites in its leaves, stem, roots, and fruits. Despite these properties, drought stress has always been one of the limiting factors affecting its growth and productivity. This study investigated the role of melatonin in the regeneration of M. citrifolia in vitro under simulated drought stress. Nodal cuttings of six-month-old M. citrifolia were inoculated into Murashige and Skoog (MS) media supplemented with 2, 4-dichlorophenoxy-acetic acid (0.5 mg/L), indole acetic acid (0.5 mg/L) and varying concentrations of melatonin (0 μM, 50 μM and 100 μM) and polyethylene glycol (PEG) 6000 (0%, 20% and 40%). M. citrifolia experienced a significant increase in plant growth, stabilized chlorophyll contents, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities under drought stress possibly because it is a drought-tolerant plant. However, melatonin was involved in the accumulation of proline and ascorbic acid at 20% PEG. Osmoregulation of solutes stimulated and stabilized the production of catalase, GPx, and SOD activities. Upregulation of glutathione S-transferase augmented the biosynthesis of glutathione during drought stress. Also, a high accumulation of carotenoid function as photo-protectants and shields chlorophyll contents from drought-induced reactive oxygen species. Consequently, 40% of hydrogen peroxide was detoxified and plant growth was boosted. Therefore, melatonin acts as a stimulant of carotenoid, compatible solutes, enzymatic and non-enzymatic anti-oxidant defensive system, protects plants against oxidative injury, and boosted the growth of Morinda. citrifolia in vitro under drought stress

OntoMathPROOntoMath^{PRO} Ontology: A Linked Data Hub for Mathematics

In this paper, we present an ontology of mathematical knowledge concepts that covers a wide range of the fields of mathematics and introduces a balanced representation between comprehensive and sensible models. We demonstrate the applications of this representation in information extraction, semantic search, and education. We argue that the ontology can be a core of future integration of math-aware data sets in the Web of Data and, therefore, provide mappings onto relevant datasets, such as DBpedia and ScienceWISE.Comment: 15 pages, 6 images, 1 table, Knowledge Engineering and the Semantic Web - 5th International Conferenc

Towards c=0 Flows

We discuss some implications of the gravitational dressing of the renormalization group for conformal field theories perturbed by relevant operators. The renormalization group flows are defined with respect to the dilatation operator associated with the $J_0^{(0)}$ mode of the $SL(2,R)$ affine algebra. We discuss the possibility of passing under the $c=25$ barrier along renormalization group flows in some models.Comment: LaTex file, 11 pages, QMW Preprint, QMW 94-2

Use of fibroscan in assessment of hepatic fibrosis in patients with chronic hepatitis B infection

Introduction: Assessment of the stage of liver fibrosis plays a prominent role in the decision process of treatment in chronic viral hepatitis.Objective: To determine the stage of fibrosis in patients with chronic HBV infection using fibroscan.Method: This is a cross sectional descriptive study involving patients with CHB with a valid transient elastography (TE) measurement. Liver function test and platelet count was determined. APRI and FIB-4 were calculated and Spermans rank coefficient was applied for correlation of transient elastography (TE) with either serum biomarkers.Results: 190 patients were enrolled, mean age 36.3years, 64.2% males and 89.9% were asymptomatic. TE correlated significantly with APRI and FIB-4 (r = 0.58; P < 0.001 and r = 0.42; P < 0.001, respectively). Most of the patients 131(68.9%) had no significant fibrosis (F0,F1) while those with significant fibrosis and cirrhosis were 59 (31.1%) and 23(12.1%) respectively.Conclusion: The prevalence of significant fibrosis and cirrhosis is high in this population.Keywords: Fibroscan, Hepatic fibrosis, APRI, FIB-

Orthology guided transcriptome assembly of Italian ryegrass and meadow fescue for single-nucleotide polymorphism discovery

Single-nucleotide polymorphisms (SNPs) represent natural DNA sequence variation. They can be used for various applications including the construction of high-density genetic maps, analysis of genetic variability, genome-wide association studies, and mapbased cloning. Here we report on transcriptome sequencing in the two forage grasses, meadow fescue (Festuca pratensis Huds.) and Italian ryegrass (Lolium multiflorum Lam.), and identification of various classes of SNPs. Using the Orthology Guided Assembly (OGA) strategy, we assembled and annotated a total of 18,952 and 19,036 transcripts for Italian ryegrass and meadow fescue, respectively. In addition, we used transcriptome sequence data of perennial ryegrass (L. perenne L.) from a previous study to identify 16,613 transcripts shared across all three species. Large numbers of intraspecific SNPs were identified in all three species: 248,000 in meadow fescue, 715,000 in Italian ryegrass, and 529,000 in perennial ryegrass. Moreover, we identified almost 25,000 interspecific SNPs located in 5343 genes that can distinguish meadow fescue from Italian ryegrass and 15,000 SNPs located in 3976 genes that discriminate meadow fescue from both Lolium species. All identified SNPs were positioned in silico on the seven linkage groups (LGs) of L. perenne using the GenomeZipper approach. With the identification and positioning of interspecific SNPs, our study provides a valuable resource for the grass research and breeding community and will enable detailed characterization of genomic composition and gene expression analysis in prospective Festuca Lolium hybrids